WoodWorks Shearwalls Canada - Change History
This document
provides descriptions of all new features, bug fixes, and other changes made to
the Canadian version of the WoodWorks Shearwalls program since its inception.
The most recent major
release of Shearwalls is Shearwalls 2020, released on December 22, 2020. The most
recent service update is Update 3, released on June 21, 2022.
This file last
updated with changes on Dec 11, 2024.
Click on the links
below to go to the changes for the corresponding release.
Shearwalls 11.4.1 – July 12, 2024
This update was released to fix problems with features implemented in
11.4 along with other bug fixes and small improvements.
A detailed description of the changes is
not yet available.
Shearwalls 2020, Update 4 (Version 11.4) – Dec 21, 2023
This update provided several new features along with numerous bug fixes
and small improvements, including
-
Input, design check, and deflection calculations
for proprietary or non-wood shear resisting elements. Note that the ability to
manually enter rigidities or ignore height-to-width ratios was removed for
standard wood shear walls, as these were intended to allow for proprietary
elements.
-
Design for compressive resistance of wall bottom
plate under end stud pack.
-
Automatic generation of dead loads on wall lines
using wall self-weights and supported weights entered for each wall.
-
Control of amount of dead load to be distributed
to shear wall end chords
-
Maximum of 7 levels rather than 6 to allow you
to model rooftop structures
-
More accurate calculation of
hold-down/compression force offset, with application to hold-down/compression
force moment arm and amplification of anchorage term in deflection equation.
-
Calculation of crushing component of deflection
equation.
-
Calculation of bending term in deflection
equation for unequal no. of end studs.
-
Updated Simpson hold-down database and present
hold-down names in the output tables more readably.
A detailed description of the changes is
not yet available.
Shearwalls 2020, Update 3 (Version 11.3) – June 21, 2022
A: Engineering Design and Loads Analysis
1. Association between Sheathing Capacity and Nail Spacing for O86-09 Design (Bug 3662)
When O86-09 design code was selected, the program
included the 5” nail spacing input choice that had been added for the Version
11, even though O86-09 table 9.5.1A did not include this option. This caused the
association between input nail spacing and the sheathing capacities to be
broken such that for 5”, 4” and 3” nail spacing, the program used the capacity
for the next lowest nail spacing listed in the O08-09. For
2” spacing the program assigns zero capacity and zero loads to a shearline with
such walls.
For the O86-14 and O86-19 design codes, there were no such problems because a mechanics-based rather than tabular approach is used for shear wall capacities.
2. Negative Dead Loads (Bug 3718)
Dead loads entered with a negative sign are now considered to be oriented upwards. Previously they were treated the same as positive dead loads.
This change allows you to adjust the distribution of dead forces to the ends of shear wall segments to account for different assumptions than those we use in distributing these forces, such as to account for mechanical uplift from cantilevered floors.
Negative dead loads are shown with the direction of the arrow reversed to point upwards. When combined with wind loads the load combination factor used is the 0.9 counteracting factor at the compression end rather than the tension end, and the 1.25 factor at the tension end.
3. Deflection and Hold-down Analysis for Overlapping Offset Shear Walls
(Bug
3665)
The analyses of hold-down forces and of shear wall deflection were not properly handling the case where offset shear walls overlap longitudinally within the same shearline.
The hold-down forces on the overlapping segments were sometimes being assigned to the wrong overlapping wall segment, and these forces were used for the hold-down component of the deflection calculation.
In the Hold-down design output table, the program was outputting the wrong hold-down wall name, location and/or position incorrectly for these hold-downs.
In practical structures, this can occur if you create a large shear wall offset, for example 4 feet, which is generally not recommended. It has been corrected, nonetheless.
4. Minimum Shearline Requirements for Torsional Analysis Message (Change 69)
The message indicating that there are not sufficient shear lines to ensure torsions for rigid diaphragm design has changed from saying that two are required in each direction to two in one direction and one in the orthogonal direction.
B: Input and Program Operation
1. Keyboard Shortcuts in Load Generation Details (Bug 3401)
In Load Generation Details and Torsional Analysis Details output viewer, the assignment of the Ctrl+V shortcut key has been changed to allow you to paste content into the document. Previously this shortcut was used to tile the view vertically, which can still be done using a command under the Window menu.
2. File Save of
Ceiling as Diaphragm Checkbox (Bug 3583)
After a project was saved with the Ceiling acts as upper-level diaphragm checkbox in Structure Input view checked, it did not remain checked when the file was reopened. This has been corrected.
3. Input Nomenclature for Foundation Elevation (Change 126)
In the Levels data group of the Structure Input Foundation elevation has been changed to Base elevation to reflect the fact that some light-frame wood buildings are on top of non-wood above-ground level such a concrete podium rather than a foundation.
4.
Crash
upon Change of Multiply Selected Sheathing after Design (Bug 3690)
After design, if the exterior sheathing type for multiply selected walls was changed to a non-wood structural panel (gypsum-based, lumber sheathing, or fiberboard), the program immediately shut down without issuing a warning.
This did not happen for interior sheathing but did happen when Both sides the same is selected. The first selection does not have to be wood structural panel (WSP), it happened when you start with one non-WSP and change to another non-WSP. It has been corrected.
C: Output and Graphics
1. Display of Manually Entered Building Masses (Bug 3458)
The display of building masses in Load Generation view now includes manually entered masses. Previously they were not included because they are not automatically generated, but since they are intermediate to generating seismic loads, they should be shown.
Since by default building masses are not shown in Loads and Forces view, it was unclear to many users where these masses were.
2. Output of Hold-down Information Instead of Vertical Elements (Bug 3665)
Occasionally, hold-down forces that came down over a segment that is
too narrow to be considered a full-height segment, or over a gap between shear walls,
were not associated with a vertical element on the level below as they
ordinarily are. No vertical element appeared in Elevation view or in the Location
column of the Hold-down Design output table. In the line in this table for the lower
level, sometimes a hold-down model from a neighboring wall is shown, along with
capacity and design ratio, when it should say Refer to upper level. At
other times these lines are blank.
This has been corrected and vertical elements now appear at all such locations.
3. Hold-down Force Symbols and Shear Force
Descriptions in Elevation View (Bug 3690)
The following changes have been made to the Elevation view legend and symbols:
a) Overturning Hold-Down Forces
The symbol S that appears below the hold-down
symbol and before the magnitude of the overturning forcehas been changed to T
for tension (upwards) forces and C for compression (downwards) forces. Separate
lines explaining T and C in the legend replace the single line for S.
The “S” meant “overturning due to shear force”,
which was not apparent to many users.
b) Horizontal Shear Force Descriptions
The descriptions under Factored Forces, Horizontal
that used to say
Vs – Shearline force
Vs / diaphragm
length
V / full height sheathing
now say
Shear line or wall
segment force V (lbs)
Diaphragm-to-collector
force V/L (plf)
Shear wall design force v = V/FHS (plf)
The descriptions were changed to indicate the
significance of each force.
4. Column Headings in Hold-down Displacement Table (Change 116)
The following changes have been made to the headings of the columns in the Hold-down displacement table of the Design Results,
a) Horizontal Hold-down Deflection Column
The final column entitled Hold defl has be changed to Horz defl, because it confused some users into thinking the value corresponds to the vertical hold-down displacement from the hold-down database, whereas it refers to the horizontal deflection given in the fourth term of the deflection equation in O86 Table 11.7.1.2.
b) Vertical Hold-down Displacement Column
The final column entitled Elong/disp has changed to Vert Displacement. Elong is an obsolete term referring to the separate calculation of the hold-down device elongation without including fastener slippage. This method is not included in the current version of the program.
5. Table Notes to Gravity-induced Lateral Demand Irregularity (Feature 266)
The notes and descriptions under the Irregularities table explaining why the program does not consider Irregularity 9, Gravity-induced Lateral Demand, have been revised to better explain why, that is, that predominant yielding mechanism, the sheathing nails, are unaffected by gravity-induced lateral demand as from a cantilevered floor contributing to overturning. Hold-downs are affected, but they do not provide significant ductility so are not the predominant yielding mechanism.
a) Numbered Note
The numbered note referring to this irregularity
has been changed from
Not applicable, as Shearwalls
does not include gravity-loaded elements that can induce lateral forces.
to
Not applicable to structures
using wood shear walls.
b) Description
In the list of descriptions of all the
irregularities,
Pertains to elements such as sloped columns that impart gravity loads to the lateral system. Shearwalls does not include such elements, so this irregularity does not apply.
has been changed to
Any such demands in a typical wood-frame structure, such as from cantilevered floors, affect the overturning force on hold-downs; however these are not the predominant yielding mechanism so this irregularity does not apply.
6. Out of Plane Shear Strength Symbol in Components and Cladding Output (Change 109)
When either O86-14 or 086-19 design codes are selected, in the legend
to the Components and Cladding table, the symbol vpb for planar shear in
out-of-plane bending has been changed to vpsb, in accordance with the
change in nomenclature in O86-14 Tables 9.3A-C.
7. Default Values in Site Information Output (Bug 3601)
Following a sequence of steps involving running design, closing, reopening, and re-running design, all the information shown in the Site Information table of the Design Results were the default values that come with the program when first installed, rather than the ones that were set before the design was originally run. However, the design results are correctly based on loads generated using the using your inputs and not the default values.
For example, if 0.52 kPa velocity pressure and gust factor of 2.4 were input in the Site Information dialog box, the output table showed 0.45 kPa and 2.0, the default values, instead of the values you input, but 0.52 kPa and 2.4 were used to generate loads.
This has been corrected and the data used for design are now shown in the output.
Previous Versions
An asterisk (*) indicates that the change was added to this record after the release of the version in which the change occurred
Shearwalls
2020, Update 2 (Version 11.2) – April 19, 2021
1. License Server Connection Error on Startup (Bug 3642)
If the current user was not the one to install WoodWorks and had not already run WoodWorks 2020 prior to update 1, an error message stating "Unable to run WoodWorks because you are not connected to the Internet or unable to contact license server" was incorrectly being displayed on start-up preventing WoodWorks from running. This happened to a small but significant number of users.
Shearwalls 2020, Update 1 (Version 11.1) – March 3, 2021
1. Crash on Design for Structures with
Non-Shearwalls (Bug 3609)
Starting with version 11.0, for any structure having a non-shearwall, the
program crashed upon running design. This has been corrected.
2. Crash on Accept Design for Shearwalls Combined
with Non-Shearwalls (Bug 3635)
For structures that have interior non-shearwalls and shear walls on the same shearline, the program crashed when the Accept Design button was pressed, even prior to version 11.0. This has now been corrected.
Examples of this configuration are a line with exterior shear walls and interior non-shear walls, and any interior line with shear walls and non-shearwalls.
3. Crash on Generating Low-Rise Wind Loads on Variable
Height Blocks (Bug 3625)
When low-rise wind loads were generated on buildings in which attached
blocks have a difference of two or more in the number of levels, the program
crashed. This has been corrected.
4. Plywood and OSB Wall Sheathing Materials (Change
124)
a) Sheathing Thicknesses
Published metric plywood and OSB wall sheathing thicknesses when converted to Imperial and shown in Wall Input view are now rounded in most cases to the nearest 32nd to conform with current publications and marketing. They had been shown to the closest 16th.
i. OSB
12 mm OSB is now shown as 15/32” rather than ˝”. This eliminates the duplicate size ˝” corresponding to 12 mm and 12.5 mm sheathing. 15 mm is now 19/32” rather than 9/16 and 18 mm is 23/32” rather than 11/16”. 18.5 mm OSB remains ľ” rather then 23/32” to distinguish it from the 18.0 mm size.
ii. Plywood
18.5 mm plywood has been changed to 23/32” from ľ”. 7.5mm plywood is still shown as 5/16”, although it is closer to 9/32”.
b) Design Thickness
When Imperial units were used, the program designed for shear resistance from both panel bending and nail strength from O86 11.6.2.2 with the nominal Imperial thickness rather than the actual metric thickness. When combined with the coarse rounding, this led to errors as much as 6% in the thickness used in these calculations. The program now uses the published metric value for design calculations even when working with Imperial units.
c) OSB Material Name
In the input list of sheathing Materials, the name OSB const has been changed to OSB.
5. Repeated Input of Non-uniform Closed Openings Category (Bug 3634)
In the Openings drop list input of the Load Generation Site Information, the second of three choices, Non-uniform, resistant, closed was repeated in place of the third choice, which should be Large, often open. When the third choice was selected, the program generated loads for an open structure, the problem was only in the wording, which has been corrected.
Shearwalls 2020 (Version 11.0) – December 22, 2020
The links below lead to descriptions of the features added to WoodWorks Shearwalls 2020, and other changes made to the program:
A: Update to CSA O86-19 –
General
2. Choice of Design Codes and Standards
3. Update of Clause References
4. Removal of Load Combinations from NBC
2. Embedment Strength for Sheathing Connection Resistance
(11.6.2.2)
3. Modification Factors Rd and Ro and
Building Categorization (11.8.1)
4. Nail Diameter Maxima (11.6.1.1 and
11.5.5.2)
5. Minimum Side Member Thickness (12.9.2.2)
1. Non-ductile Critical Design Modes (O86 11.8.1)
2. Intermediate Data for Bx used
for Torsional Irregularity (Feature 217)
3. Hold-down Forces Used to Determine Displacements for
Torsional Irregularities (Bug 3351)
4. 20% Drag Strut Increase for Low Seismic Zones (Bug 3591)
5. 125 mm Nail Edge Spacing (Change 99)
6.
Minimum Nail Penetration Depth (O86 12.9.2.2)
7. Slow Torsional Seismic Design for Structures with Numerous
Hold-downs (Bug 3602)*
9. Units in Detailed Shear Wall Design Output (Change 119)
D: Load Generation and Force
Distribution
1. Transfer of Torsional Moment Due to
Variable Accidental Eccentricity (Bug 3543)
2. Drag Strut Display and Output (Feature
177)
3. Crash on Generate Loads for Multiply Indented Structures
(Bug 3495)
4. Multi-block Low-rise Hip End Warning
Message (Change 107)
5. Design Spectral Response Accelerations in
Seismic Load Generation Details (Change 104)
6. Default Self-weight Units (Change 97)
1. CAD Drawing Import Procedure (Change 89)
2. Options Settings and Show Menu for Elevation View (Change 57)
3. Menu Item for Auto-saved Files (Change 39a)
4. Default Size for New Openings (Change 51)
5. Repeating Screen Message upon Change of Gypsum
Fastener Length (Bug 3529)
6. Crash upon Missing Wall Stud Database File
(Bug 3550)
7. View Style in Design Results Window (Change 25)
A: Update to CSA O86-19 – General
The program now
implements the CSA O86-19 Engineering design in wood design standard,
including Update 1, March 2020.
Although O86-19 is
referenced by NBC 2020, the program continues to implement the NDS 2015 design
code for the time being.
2. Choice of Design Codes and Standards
In the Design Code drop list in the of
the Design settings, the choice CSA O86-19 / NBC 2015 has been
added to the existing choices.
This selection is reflected in the Design
Settings output, the About Shearwalls box accessed from the Help menu, the
Welcome box and the Building Codes box accessed from Welcome
box.
3. Update of Clause References
All
references to O86 clauses in the program input,
output, and messages were changed to refer to the clause numbers in O86-19 if CSA
O86-19 is selected. Virtually all references to shear wall design
provisions under 11.1-11.6 changed; those in 11.7 relating to deflection and
11.8 relating to seismic design did not. References
to the structural panel tables were changed from 9.3A, 9.3B and 9.3C to 9.1,
9.2 and 9.3. and nail design clauses under 12.9.3 were changed to 12.9.4.
4. Removal of Load Combinations from
NBC
The definition of load combinations used in Shearwalls that was in O86 5.2.4.1 has been removed entirely from the design standard, which now refers to the identical load combinations listed in the NBC.
The only reference to these
load combinations, in the Hold-down Design table legend to O86 Table 5.2.4.1,
has been changed to NBC Table 4.1.3.2.A.
The
On-line Help has not yet been updated where necessary to reflect changes in the
O86-19 other than design code clause reference numbers.
The program now includes W24 OSB sheathing panels from O86-19 Table 9.3 (previously O86-14 Table 9.3C), which has values of for shear-through-thickness rigidity Bv for thicknesses 9.5 mm and 11 mm.
a) Input
In the Wall Input view, W24 has now been added to the Panel
Mark list. When a list of thicknesses the list of thicknesses 9.5, 11.0, 12.0,
and 12.5 should appear. The final two are alternative thicknesses from Table
A.9 and use design values for 11.0 mm panels.
b) Component and Cladding (C&C) Design
Because bending strength mp and planar shear strength in bending vpsb are not published in O86-19, the out-of-plane sheathing capacity for C&C design cannot be calculated.
i. Sheathing Materials by Wall Group Table
A note number “7” appears for W24 wall groups in the Notes column of the Sheathing Materials table, referring to a note saying design for C&C wind loads is not possible.
ii. C & C Results Table
In
the C&C Results table, two asterisks instead of a design capacity
appears for sheathing bending capacity for walls with W24 sheathing, referring
to a note for materials with no sheathing capacity.
2. Embedment Strength for Sheathing Connection Resistance (11.6.2.2)
In O86-19 11.6.2.2 a) for sheathing-to-framing connection resistance, in the calculation of Nu from 12.9.3.2, the side member embedment strength f1 is now permitted to permitted to be calculated as
f1 = 51 (1 - 0.1dF).
In 12.9.3.2 the formula is
f1 = 104 G (1 - 0.1dF),
where specific gravity G = 0.49 for DFP and 0.42 for CSP and OSB.
Effectively this says that it is permissible to use DFP strength for all plywood and OSB sheathing panels.
a) Setting
A new Design Setting has been added,
Use DF specific
gravity G for nail embedment strength f1 in O86 12.9.3 (as per 11.6.2.2).
When selected, the program applies the DFP G = 0.49 to the calculation of f1 for Nu
b) Detailed Shear Wall Design Output
In the Detailed
Shear Wall Design output,
i. Symbols Section
The
following symbol definitions have been added
f1 - Wood embedment
strength
G - Specific gravity of framing material
ii. Equations Section
The
equation
f1 = 104 G (1 - 0.1dF),
has been added to the Equations section.
iii. Parameter List
In the list of parameter values shown beneath the symbols, the value of G has been added, followed by (DF plywood) if DFP had been used in place of CSP or OSB.
iv. Calculations
The
choice of calculation method shows up in the nu value in the
Detailed Shear Wall Design results.
3. Modification Factors Rd and Ro and Building
Categorization (11.8.1)
In 11.8.1, Seismic
Design Considerations, General,
a) Nail
Failure Mode c)
Nail mode c) has been added to the list of modes from O86 clause 12.9.4.2 which must be critical for shear wall
failure ensure ductility. As mode c) is a double-shear mode, this has no effect
on the current Shearwalls program. Internally, the change has been made to
accommodate a possible future implementation of mid-panel shear walls.
b) Critical Panel Buckling
The proviso for the use of the ductility-related and overstrength modification factors Rd and Ro values from Table 11.5 that failure is governed by sheathing-to-framing connection has been removed from the O86-19. We were informed that the removal was in error; however Shearwalls did not implement this proviso. Refer to C: 1 below for the implementation of this proviso for this version.
c) Seismic Zone vs. IEFaSa(0.2)
The criterion from the NBC used to determine whether clauses 11.8.2 -11.8.6 are to be implemented has changed. In O86-14, these clauses they are applied if the value of IEFaSa(0.2) is equal to or greater than 0.35. In O86-19, they are applied if the Seismic Category is SC3 or SC4 rather than SC1 or SC2, these categories being determined from IES(0.2) and IES(1.0) in NBC 2020 4.1.8.5.
As the program has yet to implement NBC 2020, it still uses IEFaSa(0.2) >= 0.35 as the criterion.
i. Clauses Affected
For the higher IEFaSa values (O86-14) or SC’s (O86-19), all of 11.8.2-11.8.6 is applied as stated. These pertain to 20% hold-down force increase (11.8.2), overcapacity coefficient/ratio (11.8.3), diaphragm design force (11.8.4), diaphragms with non-wood Shearwalls (11.8.5), and 20% transfer element force increase (11.8.6).
For the lower values or categories, 11.8.7 is used, which specifies that only 11.8.6 fully applies, and that 11.8.4 and 11.8.5 apply but with overcapacity coefficient Ci = 1.0.
4. Nail Diameter Maxima (11.6.1.1 and 11.5.5.2)
The maximum nail diameter for shear wall sheathing from O86-19 11.6.1.1 has been increased from to 3.76 mm from 3.66 mm in O86-14 11.3.1.1, and the limit for walls without hold-downs (Jhd <1) from 3.25 from O86-14 11.4.5.5 to 3.33 in O86-19 11.5.5.2.
This change acknowledges the current widespread use of nails of the ASTM F1667 nail design standard rather than the obsolete B111. WoodWorks earlier received authorization to use the ASTM diameters as limits, so no there was no change to design or program operation, other than to remove a note to that effect that appears under the Sheathing Materials table when these nails are used.
5. Minimum Side Member Thickness (12.9.2.2)
The minimum plywood
or OSB side member thickness for a nailed connection from O86 12.9.2.2 has
changed from 3.0 nail diameters to 2.5.
This minimum was not
applied to the sheathing-to-framing nail connection in Shearwalls. Refer to C: 7 below for the new implementation.
1. Non-ductile Critical Design Modes (O86 11.8.1)
WoodWorks has
clarified with the design standard authorities the meaning of the following
provisos in O86 11.8.1. In both O86-19 and O86-14,
The sheathing-to-framing connections shall
be designed to yield in mode c), d), e), or g) shown in Clause 12.9.3.2 for nails to ensure ductility in the
shearwall and diaphragm.
In O86-14,
The corresponding ductility-related
seismic force modification factor, Rd, and system overstrength related force
modification factor, Ro, for shearwalls are given in Table 11.8.1, provided
failure is governed by sheathing-to-framing connection.
We have been informed
that this latter statement was removed from the O86-19 in error, and we regard
it as still in force.
We have also been
informed that both these statements mean that when Rd and/or Ro
are other than 1.0, shear walls that have brittle non-ductile critical design
modes are considered to fail. These critical modes are either the nail resistance
mode from O86 12.9.3.2 or when panel bending strength from 11.6.2.2.(b) governs
over sheathing connection strength from 11.6.2.2.(a).
We have implemented
these provisos as follows:
a) Design Search
In the design search in which parameters defining the wall
have been left unknown, the program now passes over those walls for which a
non-ductile mode governs.
b) Detailed
Design Output
If a wall has a non-ductile governing mode when all
parameters were selected or when the end of the design search was reached, a
note appears at the bottom of the section in the Detailed Design results for
that wall, saying the wall fails, giving the reason. Priority is given to panel
buckling failures if both criteria are non-ductile.
c) Design
Results
In the Shear Results table, for walls with governing non-ductile modes governs, a symbol appears next to the design ratio, and a warning is placed below the table saying that the wall failed either because of a critical non-ductile nail mode or because panel buckling governed. The note is followed by a list of failing walls.
d) Design
Summary
If any walls have a governing non-ductile mode, a line is output in the Design Summary giving the list of such walls.
2. Intermediate Data for Bx used for Torsional Irregularity (Feature 217)
At the end of the Torsional Analysis Details file, there is now a table showing the intermediate data used to determine Bx = δmax / δavg , from NBC 4.1.8.11 where δ is the structural displacement on extreme perimeter shear walls on each level induced by forces acting at +- 0.1Dnx from the center of mass on that level. Dnx is the building width on that level. Bx is used to determine torsional irregularity as per 4.1.8.6.
These data are shown for each level of the structure, each of the 4 force directions, and for the cases of positive accidental eccentricity and negative accidental eccentricity added to the torsional moment.
The table shows the shear line forces used to determine perimeter story drift (with Bx = 1.0 and 10% accidental eccentricity), the story drift on the extreme left and right shear lines, the average of the story drifts, and the ratio of maximum drift to average.
The table has notes explaining the meaning of the data and their consequences in the NBC provisions.
3. Hold-down Forces Used to Determine Displacements for Torsional
Irregularities (Bug 3351)
In detecting
Torsional Irregularities using NBC 4.1.8.11.(10) the program was using
hold-down forces derived from the worst case of positive or negative accidental
eccentricities to calculate the displacements used for both the positive and
negative eccentricities. The effect of this was to increase the lesser of the
deflections and reduce the difference in displacements that creates torsional
irregularity.
This has been corrected and hold down forces are calculated for the positive and negative eccentricities independently for the purpose of calculating displacements and
4. 20% Drag Strut Increase for Low Seismic Zones (Bug 3591)
The 20% increase in
seismic drag strut forces mandated by O86 11.8.6 was applied only for high
seismic zones, defined in O86 11.8.1 when IaSaFa(0.2)
from the NBC is greater than 0.35, however, it should have also been applied
for low seismic zones as per 11.8.7.3;
i.e. the factor should have always been applied.
Furthermore, the Drag
Strut Forces table legend referred to O86 11.8.2, which gave the increase for
hold-downs, anchorages, etc. but should have shown 11.8.6, which is for drag
struts and other lateral force transfer elements.
These problems have been corrected.
The Elevation view
legend now shows the line Drag strut = 1.2 under Factors for low
seismic zones. It correctly referred to the 11.8.6 clause number.
5. 125 mm Nail Edge Spacing (Change 99)
5” or 125 mm was added to the edge nail spacing
choices in Wall Input view. This spacing is sometimes used in publications and
occasionally in practice.
6. Minimum Nail Penetration Depth (O86 12.9.2.2)
The program
now implements the minimum nail penetration depth in O86 12.9.2.2 of 5
times fastener diameter d for plywood and OSB.
The program calculates penetration by subtracting the sheathing thickness plus the gypsum underlay thickness from the nail length. If the result is less than 5 nail diameters, the shear wall design is considered to fail.
If the program is searching through unknown parameters for a design, such a wall is passed over.
If the wall has been completely specified, a failure is reported and an existing message about zero capacity walls is shown at the bottom of the Shear Results table.
It is not possible to create this condition without the use of gypsum underlay. Even with gypsum underlay it cannot occur for standard nails, and a combination of a thick, short power-driven nail is needed, for example a 2” x 3.33 mm nail with 18.5 mm sheathing plus 5/8” gypsum underlay. In that case there is 16.25” penetration but 16.65” is required.
7. Minimum Sheathing Thickness for Nail Sizes (O86 12.9.2.2)
The program now implements
the minimum side member thickness for nail strength in O86 12.9.2.2 of 2.5 times fastener
diameter d for plywood and OSB.
After changing the panel thickness in Wall Input View, only those nails that satisfy the 2.5d minimum thickness are included in the nail selection list, so that large diameter nails are excluded when using thin plywood. This only applies to 5/16” (7.5mm) plywood, because 3/8” (9.5 mm) plywood is more than 2.5 times as thick as the largest allowable nail diameter from O86 11.6.1.1 (3.76 mm).
8. Slow Torsional Seismic Design for Structures
with Numerous Hold-downs (Bug 3602)*
For
buildings with numerous hold-down locations, an internal error slowed rigid
diaphragm seismic design calculations to the point that the program hanged for
a long time after the design button was pushed, and eventually showed Not
responding in the title bar. The slow-down was directly proportional to the
number of hold-downs, so it was significant for a structure with multiple
floors, numerous shearlines, and many wall segments.
An
example of a structure experiencing this problem had four levels with 11
shearlines on the first, second and third levels and nine on the fourth, with as
many as six segments on a shearline on each level.
The
following changes have been made to the Shear Results table legend:
- It is explained that Vhd is Vrs without Jhd, as Vhd is no longer defined in the O86.
- For the sheathing connection resistance equation:
- Equation and reference for vd based on fastener strength Nu has been added.
- The number of shear planes, ns, was removed, as it is always 1.0.
- Definitions and references have been added for shear wall factor JD, unblocked factor Jus and fastener spacing factor Js
- For the panel buckling resistance equation:
- Definitions and references have been added for the load-duration factor KD, service-condition factor KS, and treatment factor KT
- It is indicated that KD = 1.15 and KT = 1.0
10. Units in Detailed
Shear Wall Design Output (Change 119)
In the Detailed Shear Wall Design report, the
words Units shown in has been added above the column headers Equation
and Table. This is to clarify that one unit shown is for how it appears
in the tabulated results, and the other unit is the assumption used in the list
of equations.
D: Load Generation and Force Distribution
1. Transfer of
Torsional Moment Due to Variable Accidental Eccentricity (Bug 3543)
The method that was
used to transfer the torsional moment for rigid diaphragm analysis downwards
between levels by applying the upper-level force at the center of mass of that
force to the level below, assumes that the accidental eccentricities (ae) are
the same on each level, however ae's can be different due to a different
building width on adjacent levels. This could lead to an inaccuracy in the
torsional analysis used to distribute the seismic forces to shear lines on the
lower level.
This has been
corrected by applying an effective accidental eccentricity on the level below
equal to (aeu*Fu + ael*Fl) / (Fu
+ Fl), where aeu and ael are the design
code mandated ae's on the upper and lower level, and Fu and Fl
are the total forces from loads applied on each level. Refer to the Online Help
topics on the vertical distribution of rigid diaphragm shear force for a
derivation of this adjustment.
In the Torsional
Analysis Details output, when this occurs, a line is added to give the
effective accidental eccentricity and the adjustment equation. The line showing
the total force F used for torsional analysis on the level now shows the value
of Fl, the force from loads only on that level. This appears
regardless of whether differing ae's exist, as it is useful information at any
time.
This issue affects
seismic analysis as this is the only design case with accidental eccentricity.
To gauge the impact
of the change:
Case 1 - A penthouse
on the upper level, assuming that the mass per unit foot is the same as on the
lower level. The maximum difference occurs when the penthouse is 41% of the lower-level
width, where the effective ae is 60% of the regular ae.
Case 2 - A 6-story
tower where five upper stories are narrow, supported by a podium base that is 3
times the width of the tower. The effective ae is roughly half the regular ae.
Case 3- A building
shaped like an inverted pyramid. Such a building would be very non-conservative
in that the additional width in two dimensions would not be accounted for on
the level below. Such buildings are rare but exist.
2. Drag Strut Display and Output (Feature 177)
The following changes have been made to the display of drag strut forces in Elevation View.
a) Location of Symbol and Force
The symbol with a circle and arrow showing the drag strut force has been moved up to be just below the top of the wall. Previously the forces were shown at the top of openings. The drag strut forces are typically in the top plate of the wall, not the opening headers, and this change avoids conflict with the new force-transfer strap forces.
b) Direction of Arrow
The direction of the force arrow now indicates whether the drag strut is in tension or compression at that point. Previously the arrows always pointed away from the opening or wall end.
An arrow in the direction of the shearline force is in tension, one contrary to the shearline force is in compression. An arrow in the same direction as the shearline force pointing into an opening segment is dragging the force over the opening into the full height segment. An arrow in the opposite direction pointing into an opening segment shows the full height segment resisting force being pushed into it from over the opening.
The following change has been made to the output of drag strut forces in the Collector Forces table of the Design Results (formerly Drag Strut Forces)
c) Negative Compression forces.
The magnitude of the drag strut a force in compression is shown with a negative sign. The legend explains that positive numbers are in tension, negative ones in compression.
3. Crash on Generate Loads for Multiply Indented Structures (Bug 3495)
For a specific single
block multi-level long structure with numerous small indentations, the program
crashed upon generating seismic loads. This has been corrected.
4. Multi-block
Low-rise Hip End Warning Message (Change 107)
In the screen message
that appears when low-rise wind loads are generated with multiple blocks, the
program would warn of both hip ends being treated as side panels and of unequal
hip end slopes even if only one of these was true. This has been corrected.
5. Design
Spectral Response Accelerations in Seismic Load Generation Details
(Change 104)
Based on the Design
Setting selection for NBC 2010 and NBC 2015, the values of design spectral
response accelerations that were used in the calculation of lateral seismic
design force at the base from NBC 4.1.8.11 are now output in the Seismic Load
Generation Details. If NBC 2010 is selected S(0.2), S(0.5), and S(5.0) are
output and if NBC 2015 is selected S(0.2) and S(2.0) are output.
6. Default Self-weight
Units (Change 97)
In the Default
Settings, the units for self-weight have been changed from kN/m2 to
kPa. These units are equivalent, but kPa is used more often in
publications.
1. CAD Drawing
Import Procedure (Change 89)
The CAD Import Wizard
has been improved to make it easier and more intuitive to add drawings for
multiple levels. Previously, it was unclear to some users that you had to press
Start positioning to scale the CAD drawing, and the sequence between scaling and
adding new levels could be confusing. The Wizard now guides you through a
sequence of steps for each level.
2. Options Settings and Show Menu for Elevation View (Change 57)
The following changes
have been made to the Display items in the Options Settings, and/or the
corresponding items in the Show menu, which control program elements to display
or output.
a) Center of Loads and Center of Rigidity
Checkboxes for Center of loads and Center of rigidity have been added under Elevation view in the Options Settings. Previously, they had only been in the Show menu.
b) Aspect Ratio
Aspect ratio has
been moved to appear below Segment numbers.
c) Nailing Information and Legend
The Nailing information used to mistakenly hide and show the legend. It has now been renamed Legend. Nailing information now is shown and hidden via the Sheathing information item.
d) Shear Force and Capacity
An item has been added to show or hide the design shear force and combined
capacity information, which previously were always shown. This allows the
entire material specification \to be removed if all Show menu items are turned
off.
3. Menu
Item for Auto-saved Files (Change 39a)
A new menu item Open Autosaved File menu
has been added under File menu to provide direct access to auto-saved
backup files BackupPre.wsw and BackupPost.wsw. Refer to the
On-line Help for the use of these files. Explanatory status bar messages are
displayed if you hover over the menu items.
4. Default Size for New Openings (Change 51)
Now, the default size
for new openings is 3 feet with an offset of 2.5 feet from bottom of the wall,
approximating the size for a window. Previously the default size for a new
opening was 6.75 ft approximating the size for a door.
5. Repeating Screen Message upon Change of
Gypsum Fastener Length (Bug
3529)
In the Wall Input
form, when fasteners less than 1-3/4” was selected for the GWB Type X material,
and then you make any other action, a message pertaining to nail sizes intended
for wood structural panels appeared. It kept re-appearing, making it impossible
to proceed to the design stage unless you selected a larger fastener. This has been corrected.
6. Crash upon
Missing Wall Stud Database File (Bug 3550)
If a wall stud
database file used in a Shearwalls project was no longer in your installation
or no longer referenced by the database.ini file, the program would show a
blank Framing Material in wall input view, and eventually crash upon
design if an available material was not selected in its place. The program now
outputs a warning and selects an available material if it detects this
condition.
7. View Style in Design Results Window (Change 25)
After running design,
thee Design Results are now shown in the last selected view style, Wide View or
Preview. Previously it returned to
Preview each time. The program still defaults to Preview on the first design run.
8. View Change of Spelling in User
Interface (Change 111)*
All references in
the user interface to “shearwalls” and “shearlines” have changed to “shear
walls” and “shear lines”, as this is the correct spelling and the one used by
CSA O86.
Shearwalls 10.3 – Design
Office 10, Service Release 3 – June 11, 2020
1. Vertical Distribution of Rigid Diaphragm Forces (Bug 2733)
a) Compounding of Accidental Eccentricity
Starting with version 10.2, the vertical distribution of rigid-diaphragm shear force amplified the effect of accidental eccentricities on lower levels, such that the total force applied to the shearlines was increasingly larger than the applied shear force F as you moved down the structure. The total shear line force should equal the applied shear force F on that level and all levels above, plus the effect of taking the worst-case of positive and negative accidental eccentricities on each level. This effect is usually small, creating shearline forces typically 10% greater than the applied shear force F, but the amplification of eccentricities created shear forces much larger than F, and an overly conservative design.
This amplification occurred because the shearline forces created using the effect of accidental eccentricity were applied to the level below and used to determine torsions on that level, so that effectively the center of mass from the upper level was shifted by the accidental eccentricity n-1 times at the base of an n-level structure, when it should only be shifted once.
This has been corrected.
b) Vertical Transfer of Rigid Diaphragm Wind
Forces for Cantilevered Diaphragms (Bug 3526)
For wind loads, the program applied the shear line forces from flexible diaphragm analysis on the level above to rigid diaphragm torsional analysis on the level below. This was intended as a convenient way to apply the total loading on the level above at its center of loading to the level, but can be inaccurate in the case of cantilevered diaphragms such as occur at roof overhangs and where perimeter walls are non-shear walls.
The program now applies the total vertically accumulated load from the levels above at the centroid of these loads to the level below, for wind loads as well as seismic loads.
2. User-Defined
Shearline Forces for Rigid Diaphragms (Bug 3528)
User-defined forces
entered in load input view were being added to shearline forces already derived
from rigid diaphragm torsional analysis of applied loads, however such forces
used to model the effect of forces from adjoining structures should be included
in torsional analysis. As a message that appears when load input view is
invoked, giving this as a reason to add these forces, they are now treated as
if they were loads on the level on which they are entered and applied to the
torsional analysis.
An exception is made
when there are no applied or generated loads on the level, only user-applied
shear line forces. In this case we can assume that you do not want to perform
rigid load distribution and wish to analyze individual shear lines with forces
calculated manually.
Furthermore, for wind
loads, the force was transferred to the level below only if it was defined for
flexible diaphragm analysis as well as rigid. For seismic loads, it was not
transferred below at all. This inconsistency has been corrected by this change,
and if both loads and shearline forces are applied on a level, the effect of
the forces is transferred to the level below as if they were loads. If only
user-applied shear line forces are added, there is no vertical transfer. Note
that flexible diaphragm user-applied forces are still transferred below in all
circumstances.
3. Fundamental Period Ta for Single-Storey Buildings
When calculating the
fundamental period Ta using the formula in NBC 4.1.8.11 (4) (a) for
single-storey structures, Ta = 0.05 hn3/4 + .004L, the
value of L, the shortest distance between shear resisting elements, was mistakenly
divided by about 16.4, rendering this contribution negligible, so that the
period was effectively the same as that used for multi-storey structures
from 4.1.8.11 (3) (c). hn is the building height.
As the same spectral
acceleration value S(Ta) is used in the generate loads for all
values of Ta less than 0.2, from 4.1.8.4.(9), this will not
have an effect except for very long structures. The value of Ta for
single-story structures is too low to impact other design code provisions based
on Ta.
For example, for a
one-storey, flat-roofed 24’ x 40’ building, the program calculated periods of
0.0994 s in the east west direction and 0.0987 s in the north-south direction,
but these should be 0.127 and 0.146, respectively. These values appear as the
default Ta in the Site information dialog and, rounded to 0.099, in
the Seismic Load Generation details.
This problem has been
corrected.
4. Storey Weight with Manually Added Building Area Masses (Bug 3537)
When manual area
building masses were added to lines or walls in both the E-W and N-S
directions, the story weight Wx used to generate seismic loads as
per NBC 4.1.8.11 (7) was inaccurate in an unpredictable way depending on load
length and the tributary width, and could be several times higher or lower than
the weight of the input masses. The incorrect weights appeared in the base
shear distribution table of the Seismic Load Generation Details and the Seismic
Information table of the Design Results. This has been corrected.
This did not occur
when manual masses were entered in just one direction.
In a typical example
of a single block of 40 x 40 feet with a gable roof with 25 psf roof self-
weight and 3 manually applied 30 psf area building masses with a tributary
width of 5 feet on lines A, B and 1, Wx was 130,350 lbs when it
should have been 62,100 lbs.
Masses are used to
generate loads in both directions, so it was possible to model all building
masses by adding them to shear lines in just one direction to avoid this
problem, which has been corrected.
The program was
adding manually entered shear line forces in one direction only to forces
created by the flexible distribution of low-rise wind loads from southeast and
northwest windward corners, even though “Both” was selected as the direction
when inputting these forces. The incorrect forces appeared in Plan view and the
Shear Results and Deflection tables of the Design Results.
In an example
project, a N->S shear line force was shown as 4153 lbs when it should be
4653 lbs. In the S->N direction, it was correctly shown as 4653 lbs.
6. Crash upon Adding Uplift or Dead Loads with Vertical Shearline Offsets
(Bug 3518)
The program crashed
upon adding dead or wind uplift load to shearlines that had vertical offsets
between levels. However, these loads could be added to shearlines that lined up
and had no vertical offsets. This has been corrected.
Shearwalls 10.2 – Design Office 10, Service Release 2 – July 30, 2019
1. Use of CSA O86-14 with NBC 2010 (Design Office
Feature 24)
The program now allows you to select the CSA
O86-14 wood design standard with the 2010 NBC building code. Although the
O86-14 is referenced by NBC 2015, it is permissible to use it with the NBC
2010, which references CSA O86-14, and some jurisdictions have not yet adopted
NBC 2015.
If there is a conflict between CSA O86-14 and
NBC 2010 provisions, the NBC 2010 provision is used to ensure compliance.
a) Input
In the Design Settings, the choice CSA O86-14 / NBC 2010 has been added to the Building code dropdown box.
For
those jurisdictions still complying with NDS 2010, this option allows for shear
wall design based on nail strength and panel buckling introduced with O86-14,
rather than the more conservative tabular approach used in previous editions.
This and other differences with using O86-14 as opposed to O86-09 are described
in Shearwalls
9.3 - CSA O86-14 Design Standard, below.
c) Program Information
The design codes and standard chosen are reflected in the Welcome box, the Help/ About Sizer box, and the Building Codes box, and in the Design Settings output.
2. Vertical Distribution of Rigid Diaphragm
Shearline Forces (Bug 2733)
We have changed the way the program
incorporates forces from shearlines on upper levels in the rigid diaphragm
analysis on the level below.
a) Previous Procedure
In versions before Shearwalls 10.2:
i. Wind
For wind design Shearwalls included the unfactored shearline forces derived from flexible diaphragm analysis on the level immediately above and added them to the applied loads on the level for which rigid analysis was being performed. The shearline force was then factored by 1.4 for wind design.
ii. Seismic
For seismic design Shearwalls included the applied loads from all levels above and added them to the applied loads on the level for which rigid analysis was being performed.
b) New Procedure
For both wind and seismic design, the
shearline forces arising from rigid diaphragm analysis from the level
immediately above are applied to the rigid diaphragm analysis on the floor
below. For each shearline, the worst case of forces from positive and negative
accidental eccentricity on the level above are those which are transferred.
c) Background and History
i. Rationale for Previous Procedure
When the rigid diaphragm procedure was implemented along with multi-story analysis in version 2002 of the program, there was concern that the torsional effect of the accidental eccentricities applied on the level above should not be carried through to the level below for two reasons:
1. Probability of Simultaneous Occurrence
It was thought that accidental eccentricity is entirely to account for inaccuracies in the distribution of mass in a structure, and that it was unlikely that these inaccuracies or variabilities would occur on each level and in the same direction.
2. Compounding of Accidental Eccentricity
There was concern that the eccentricity would unnecessarily compound, that is, the effect of eccentricity on the level above creates amplified forces that would be further amplified by the eccentricity on the level below.
ii. Implementation of Previous Procedure
1. Use of Flexible Diaphragm Forces
We received guidance at that time that it would be acceptable to apply loads derived from flexible forces on the floor above to rigid analysis on the level below. This was applied to both wind and seismic design, even though there is no requirement for accidental eccentricity for wind design.
An accidental eccentricity of 10% of building width is required for seismic design as per NBC 4.1.8.11.(11).
2. Use of Applied Loads for Flexible Diaphragm Seismic Design
The seismic requirement for flexible diaphragms of 5% accidental eccentricity, from NBC Structural Commentary 174, was added to the program for version 8, in 2011. To avoid compounding this eccentricity, applied loads on the levels above were used in lieu of shearline forces. This was an internal change only, there is no effect on the resulting torsional moments.
d) Reason for Change
i. Probability of Simultaneous Occurrence
The USA ASCE 7 C12.8.4.2 says that it is “typically conservative to assume that the center of mass offsets of all floors and roof occur simultaneously and in the same direction.” That is, as we cannot know for certain which levels and directions the accidental eccentricities occur in, it is best practice to assume they occur on all levels.
ii. Effect of Compounding vs Flexible Diaphragm Inaccuracy
Typically, accidental eccentricity adds
approximately 10% force to the shearline experiencing the greatest effect.
Compounding this effect on the floor below by adding 10% of 10% = 1% is not a
significant increase and is much less than the inaccuracy that arises from
using the flexible diaphragm forces from the shearlines above. Flexible
diaphragm analysis can result in a markedly different distribution of force
than the rigid diaphragm force, and by using flexible forces, the program was
not transferring the inherent torsion from the floor above to the one below.
iii. Natural Component of Accidental Eccentricity
According to NBC Structural Commentary 175, about ˝ of the 10% accidental eccentricity is due to natural torsional effects such as dynamic amplification, so that component should always be transferred to the level below.
iv. Wind Loads
As there is no accidental eccentricity requirement for wind, the rationale for the previous procedure does not apply to wind design, which should use the forces that arise from rigid diaphragm analysis.
e) Consequences of New Procedure
i. Distribution of Non-torsional Direct Forces
The new procedure uses the direct forces due to
shear wall stiffness on the level above, rather than those arising from
flexible analysis. As we are assuming rigid diaphragms on all levels, this is a
significant improvement in the accuracy of the procedure.
ii. Distribution of Inherent Torsional Forces
The new procedure transmits inherent torsional forces
due to physical offset between the center of mass and center of rigidity, and
these forces contribute to torsion on the level below. This is the correct
procedure, as an object when subject to torque twists throughout its whole
length. The old procedure did not transmit torsion between levels.
iii. Distribution of Accidental Torsional Forces
On each line, the program transmits the maximum
force from positive and negative accidental eccentricity. As such, the new
procedure will transmit the increase in force due to accidental torsion but
will not transmit the torsional effect of that force, as the worst case of the positive
and negative accidental torsions on opposite extremities of the structure tend
to cancel.
We believe this is an acceptable compromise
between the conservative procedure described in ASCE 7 C12.8.4.2, and the
non-conservative procedure of not including accidental eccentricities from the
floor above on the floor below at all.
3. Vertical Transfer of User-applied Seismic
Shearline Forces (Bug 3467)
When a seismic shearline force was added
directly to a shearline using the Add as a factored force directly… input
in the Add Load input form, for rigid diaphragm analysis the force affected
only the level it was added on and was not being transferred below for
inclusion in the torsional analysis on the level below.
This has been corrected in the course of
implementing the changes in Bug 2733, above, Vertical Distribution of Rigid
Diaphragm Shearline Forces.
4. Multiple Wall Selection in Load Input View (Feature
252)*
It is now possible to select multiple walls on
which to apply loads in the Add Load dialog. Once walls are selected using the
Control Key or Select All command, upon entering the Add Load dialog,
- Point loads cannot be selected,
- Apply to is disabled and shows Selected Walls,
- The From and To locations are blank and disabled,
- The Add as a factored force directly to the shearline is not available.
Loads are then added on all selected walls,
with the Magnitude From and To being the load magnitude at the
start and end of each wall.
5. Wind Load Generation on Multiple Blocks
The following
problems pertaining to the generation of wind loads on adjoining blocks have
been corrected.
a) Low-Rise End Zone in Interior of a Building
Face (Bug 3472)
When the wind
load method for low buildings from NBC Figure 4.1.7.6.-A. is used for multiple
blocks, end zones were created at the end of each block, for both walls and
roofs. This would create unnecessary end zones in the interior of the structure
where one block joins another.
For walls, these
end zones were created on interior corners, and where the end of one block is
collinear with the side of another block. For roofs, they are created when a
hip roof joins a block with a side panel of the same angle, so end zone is
created in the middle of a continuous compound roof panel.
End zones are no
longer created in these areas, which are considered part of the building faces
1-4.
b) Low-rise End Zone for Shadowed Blocks (Bug
3464)
When a block was
adjoined to another block such that there were no walls on one of the faces of
the block, the end zone on both walls and roof panels on the opposite face of
the block would extend the entire width of the block, rather than the end zone
width specified in NBC Figure 4.1.7.6.-A. This would create larger wind loads
than expected on the face.
c) Shadowed Blocks with Roof Overhangs (Bug 3465)
When a block with
roof overhangs was adjoined to another block, the program would create loads on
the roof the block was adjoined to in the portion shadowed by the block, even
if the Exclude roof portion covered by other block checkbox in the Load
Generation input was checked. This happened when using the load generation
procedures for low buildings and for all other buildings.
6. Low-rise Wind Load Generation for Flat Roofed Buildings (Bug 3474)
In the case of
buildings with flat roofs, the generation and distribution of low-rise loads
using NBC Fig 4.1.7.6 were incorrect in several ways. In such buildings, the
longest direction of the building is considered to be the direction parallel to
the ridge line for buildings with roofs. The following problems were identified:
- Case A (transverse to long direction) loads were being generated on end walls; however such walls are not loaded in the NBC model.
- Some Case A loads were being created with the magnitude intended for Case B loads, and vice versa.
- For torsional analysis of load Case B (wind force parallel to long direction), no force was being included parallel to the long direction.
These problems
occurred on all levels of the structure and have been corrected.
7. Design Spectral Acceleration Values in Seismic Load Generation Details
Output (Change 104)
The design spectral
acceleration values S(T) at period T = 0.2, 0.5, and 5.0 from NBC 4.1.8.4.(9)
are now output in the Seismic Load Generation Details file under the Total
Design Base Shear table. These values are used to calculation the maximum base
shear Vmax from 4.1.8.11.(2)(c), and the overturning reduction coefficient J
and higher mode factor Mv from 4.1.8.11.(6). Their inclusion should
some of the other calculations shown more transparent, such as the equivalence
of Vmax and Vcalc for certain site classes and locations,
because S(0.5) = S(0.2) = S(Ta) for Ta <= 0.5 for cases. Refer to NBC
Commentary J-140 which shows this situation for Site Classes D and E in
Vancouver.
8. “Getting Started” Steps (Change 103)
The instructional
steps that appear when the program is run or “Getting started” is invoked from
the toolbar have been revised, clarified and updated. Some of the more
significant changes are:
a) Default Values
A “Step 0” has
been added suggesting setting defaults for building elements, and the
subsequent steps indicate how those defaults are used to create the structure.
b) Edit Walls
Explanations of
the ability to change the location and size of walls via the wall input form,
the selection of Standard Walls, designing for unknowns, and designing as a
group have been added.
c) Edit Hold-downs
A Step 7 has been
created for editing hold-down device information, by moving instructions from
other steps.
d) Generate Loads
An instruction to
set the Wind Load Generation Procedure has been added, and the procedure of
creating seismic loads in stages with self-weights on each level explained more
clearly.
e) Add or Edit Loads
The need to add
dead loads to counteract overturning, and wind uplift loads, has been
emphasized. An explanation of changing building masses and returning to
regenerate loads has been added, as has the case of not generating loads and
adding loads to check a single shearline. The unusual case of modifying generated
loads has been removed.
f) Design
Several design
settings have been added to the recommendation to set the Rigidity and
Deflection options before designing. The mention of design processing time has
been removed, as it is no longer a major issue.
g) Accept or Adjust Design
A Step 15 has
been added for the Accept Design feature.
h) Detailed Results Output
The step formerly
called “Log File Output” has changed to Detailed Design Results and
lists the separate buttons and associated files for wind load generation,
seismic load generation, and torsional analysis, that used to be in one file.
9. Force on Shearline with No Full Height Segments (Bug 3461)
Due to numerical
rounding, some shearlines with numerous non-full-height sheathing segments and
no full-height sheathing segments were assigned a shearline force when they
shouldn’t have been. These shearlines were included in the Shear Results output
table and a failure reported for them.
This problem happened
infrequently and has been corrected.
10. Drawing of Vertical Element for Offset Openings in Elevation View (Bug 3463)
When the end of an
opening on an upper storey is over the interior of an opening on the floor
below, the drawing in Elevation view of the vertical element extending from the
bottom of the upper floor joist to the top of the opening was no longer visible
because it was obscured by the gray shading over non-full-height sheathing
segments that was introduced with version 10.
This has been
corrected.
11. Default Imperial Snap Increment
(Change 94)
The default snap
increment when Shearwalls is shipped is 100 mm, so when you changed your
default unit system without adjusting the snap increment and opened a new
project, the snap increment would be 3.94”, which is awkward to work with. The
program now uses a default of 3” in this circumstance.
If you reset to the
original setting while in Imperial units, it is reset to 3” rather than
3.94”.
12. Wind Uplift Loads on Selected Walls (Change 95)
For wind uplift
loads, in the Application input of the Add a New Load dialog box, you
can now add the loads to selected walls. Previously only the full wall line was
available.
13. Display Control for Hold-down Design and Drag Strut Force Tables (Bug
3228)
The inclusion of the Hold-down Design and Drag Strut Forces tables in the Design
Results output is now controlled by separate items in the Show menu and in the Options settings.
Previously they were both controlled by a single item in the Loads and Forces settings.
14. Colour of Selected Shearlines (Change 96)
When a wall is
selected in Plan view and turns orange, the other walls on the shearline turn a
darker colour of orange (or brown). Previously they were purple.
15. Order of Framing Materials in Wall Input (Change 100)
The dropdown list of
in the Materials input in the Framing section of Wall Input View
was mistakenly ordered alphabetically, so that proprietary SCL materials rarely
used as wall studs were given first. This has been corrected and common lumber
materials appear first.
Shearwalls
10.1.1 – Design Office 10, Service Release 1a – May 7, 2019
1. Deflection Convergence for Close to Zero Force on Segment (Change 45g)
The convergence routine
for equalizing deflections along the shear wall as required by SDPWS 4.3.3.4.1
sometimes left a small residual force on a segment that should not attract any
force, causing the program to report that it could not equalize deflections.
The program now zeroes out the force if it is less than 0.05 plf, that is, what
appears as 0.00 in the output. Note that it adds this small force back into the
pot to be redistributed to other shearlines, so it isn’t leaking forces if
several segments are zeroed out.
2. Missing Framing Material Crash Upon File Open (Bug 3439)
When a project file
was opened opens that contained a framing material that was not amongst the
materials listed in the Framing Materials drop down, starting with
Version 10.1 the program crashed instead of showing you a message about the
missing database file.
The message has been
restored and the program now longer crashes in this situation.
Note that problem can
be rectified by activating the material database file with Database Editor.
3. Standard Wall Nail Diameter Persistence (Bug 3427)
Values of power-driven
nail diameters entered into Standard Walls were not being saved, so that when
standard walls created with a nail diameter, are used when the program is
reopened, the nail diameter used was the default diameter based on the common
nail of the closest length to the power-driven nail.
This has been
corrected and standard wall nail diameters now persist when a file is reopened.
Shearwalls 10.1 –
Design Office 10, Service Release 1 – March 27, 2019
The links below lead to descriptions of the changes made for version 10.1 of WoodWorks Shearwalls.
A: Building Model and Shear
Wall Design
1. Power-Driven Nail Design
Using CSA O86-09 (Bug 3406)
2. Design Assumptions for Weight
Irregularity 2
3. Constant Detection of
Torsional Irregularity 7 for Seismic-only Design (Bug 3350)
4. Data Related to Hold-downs in
Standard Wall Groups (Bug 3409)
5. Update of Roof Joining (Bug
3377)
6. Outsize Openings after Change
of Wall Height (Bug 3347)
7. Gypsum Underlay in Sheathing
Materials Table Legend (Change 43)
8. Deflection
Settings Output when Deflection Analysis not Performed (Change 83)
B: Load Generation and
Distribution
1. Separate Wind and Seismic
Details File (Change 1)
2. Generate Loads Dialog Update
(Change 8)
3. Update of F(T) in Site
Information
4. Nonsensical Seismic Forces
(Bug 3362)
5. Torsional Analysis Report for
Flexible Diaphragm Wind Design (Change 55)
6. Seismic Load Generation
Details Formatting
7. Wind and Seismic Procedure in
Site Information Table (Change 17)
C: Input and Program Operation
1. Re-appearance of Plan View
Input Forms (Change 37)
2. Crash on Corrupted or Empty
Hold-Down Database (Bug 3375)
3. Log File Menu Item (Change 2)
4. Link to Video Tutorials in Help Menu (Change 29)
5. Wall and Shearline Input Form
6. Disabled Worst-Case Rigid vs
Flexible Diaphragm Setting (Change 54)
7. Dropdown Box Style for Wall
and Opening Hold-down Input (Change 82)
8. Tool Bar Menu Item Spelling
9. Warning and Informational
Messages
A: Building Model and Shear Wall Design
1. Power-Driven Nail Design Using CSA O86-09 (Bug 3406)
The following
problems when using the CSA O86-09 design code is set, pertaining to the design
of shear walls using power driven nails according to Note 5 of Table 9.5.1A, which
refers to the procedure in A9.5.1, were corrected.
a) Shear Capacity Adjustment Factor
The program was using the capacity corresponding to the standard nail in Table 9.5.1A smaller than the power-driven nail, then increasing the capacity listed in table by the square of the ratio of the power nail to the standard nail. However, A.9.5.1 says to use the standard nail size larger than the power nail size and decrease the capacity by the square of the ratio.
This created small errors in capacity for nails greater than 2.84 mm in diameter, the smallest standard nail diameter in table 9.5.1, and for known sheathing thickness, power-driven nails less than 2.84 mm diameter had zero capacity when they should have had a factored capacity.
b) 80% Diameter Rule
The program was allowing nail sizes less than 80% of the smallest size listed in Table 9.5.1 (2.84 mm) and calculating nail size adjustment factors from A9.5.1 based on that, even though A9.5.1.1 limits the allowable nails to those within 80% of the sizes listed in 9.5.1. These factors were only applied for unknown sheathing thickness due to item a), above.
Note that the smallest standard nail size in Shearwalls is 2.87 mm, corresponding to the ASTM F1667 wire gauge size corresponding to 2.84 in the obsolete CSA O86 B111 nail standard. The program however limits nails to at least 80% of 2.84, or 2.272 mm.
2. Design Assumptions for Weight Irregularity 2
The following changes were made to the
detection of Structural Irregularity 2 - Weight (mass) in NBC Table 4.1.8.6.
a) Definition of a Storey (Bug 3423)
The program was using the definition of a “storey”,
italicized in Table 4.1.8.6 to indicate that is from the definitions in Division
A, 1.4.1.2, as the distance from the top of one floor to the top of the floor
above it. The roof was considered a separate storey because of the line in
4.1.8.6 saying “A roof that is lighter than the floor below need not be
considered. “, implying a heavier roof need be considered as a separate storey.
However, we have received advice that the
same definition of building levels used for vertical seismic force distribution
should be used, that is, from the middle of the wall on one level to the middle
of the walls on the level above. In this model, a roof is considered part of
the upper level.
The reason for this re-evaluation is that
the purpose of the weight irregularity is to make sure the structure behaves as
assumed in the Equivalent Static Procedure, which is based on the first
(near-linear) mode of the “lumped mass” dynamic response model that is used for
vertical seismic load distribution. The linear mode assumption requires a
relatively uniform mass distribution amongst the storeys.
Furthermore, an identical irregularity
provision in the USA ASCE 7 Table 12.3-2, Irregularity 2, uses the term
“effective mass”, rather than the weight of a storey.
The interpretation of a storey as per the literal
NBC definition caused problems with the following situations, that are
eliminated by using the vertical seismic force distribution definition:
-
at the
definition of a storey from a floor to a ceiling was not being applied for the
case of roofs on top of cathedral ceilings
-
if
buildings have trusses and you enter the mass of the whole truss system,
including the ceiling, as the roof load, when the ceiling should have been part
of the upper storey.
-
when
partition wall masses were incorporated into the mass of the floor load, they
would be placed on a storey below where they should be
b) Inclusion of 25% of Snow Load (Bug 3422)
The storey weight for the roof did not
include 25% of the snow load that is used in seismic load generation, but it
should have been included, as the irregularity description
in Table 4.1.8.6 includes the symbol Wi,
which is defined in NBC 4.1.8.2 as a portion of W, and in the definition of W,
it includes 25% of the snow load.
Therefore, the snow load is now included in
the weight of the uppermost level as defined in item (a) above.
3. Constant Detection of Torsional Irregularity 7 for Seismic-only Design
(Bug 3350)
The program reported
a torsional irregularity for all or most structures when only seismic loads
were applied to the structure, regardless of whether this torsional
irregularity existed. As a result, the Design
Summary indicated that due to an irregularity, seismic design was not
valid, and the Irregularities table
in the Design Summary showed the irregularity 7 failing in one direction, and a
red note at the top saying the Equivalent Static method is not available for
that reason. This has been corrected.
4. Data Related to Hold-downs in Standard Wall Groups (Bug 3409)
-
If Design in Group was not selected, the
wall would no longer be designated as being one the Standard walls. Extra
design groups would be created for all the walls affected.
-
If Design in Group was selected, the change
would be propagated to all other walls that were part of the Standard wall
group.
a) Hold-down Data
The following data were not available for
selection in Standard Wall mode, but were being treated as Standard Wall
parameters:
-
hold-down
model,
-
number of
brackets,
-
whether to
apply the same hold-down to the openings.
b) No. of End Studs
The number of end studs, which is used only for hold-down design, has been removed from the standard wall definition for the purpose of design grouping but is retained in the Standard Wall mode of Wall Input View for the purpose of creating default walls.
Hold-down related information is no longer included in the Standard Wall definition because hold-downs are designed separately from walls, and it is desirable to group walls according to wall materials only.
5. Update of Roof Joining (Bug 3377)
For multiple blocks, the program occasionally
failed to update the roofs according to the input in the data group Construction in Roof Input View in the
following ways:
a) Disabled Joined Selection
If there is another block that a roof could join to, the Joined selection was sometimes disabled so the operation was impossible.
b) Gable and Hip Selections
When roofs are joined in the N-S direction, the Gable and Hip selections sometimes had no effect and the roof remained joined when selected.
These have been corrected.
6. Outsize Openings after Change of Wall Height
(Bug 3347)
When the wall height is changed in Structure input, the program now adjusts
the top of any openings to ensure that they remain within the confines of the
wall and removes the openings that would have no height if this is done.
7. Gypsum Underlay in Sheathing Materials Table
Legend (Change 43)
The legend entry GU - Gypsum underlay thickness is now
displayed in Sheathing Materials table
in the Design Results when CSA O86-14/NBC 2015 is selected. Previously it displayed only when CSA O86-09/NBC 2010 was selected.
8. Deflection Settings Output when Deflection
Analysis not Performed
(Change 83)
In the
line saying Linearized deflection
equation in the Design Settings output, if Include deflection analysis is unchecked in Design Setting, No deflection analysis is shown rather
than Never or Always. The deflection equation is irrelevant if there is no
deflection analysis, and the Include
deflection analysis setting was not previously reported in the output.
B: Load Generation and Distribution
1. Separate Wind and Seismic Details File (Change
1)
The program now outputs two separate files for
wind and seismic load generation, rather than both in one file as before. The
file extensions are .sws and .sww instead of .log. The files are accessed by two icons in the toolbar.
2. Generate Loads Dialog Update (Change 8)
In Generate
Loads dialog, the following values reverted to their original values after
being edited and you clicked anywhere outside the box before generating loads:
Seismic loads:
-
all
self-weight text fields
-
horizontal
projection check box
-
use wall
self-weights…for Jhd calculations check box (Canada only)
Wind loads:
-
line/area
load radio buttons
-
C&C
wall loads check box
The program now retains all the inputs.
3. Update of F(T) in Site Information
The following problems regarding the update of
site coefficients F(T) in the Site Information Dialog when the NBC 2015 design
code setting is selected have been corrected. These values are editable when
Site Class F is selected, as site specific analysis is required according to
NBC 4.8.1.4.(6). Otherwise they are disabled and the values from Tables
4.1.8.4.-B-F appear.
a) Site Classes A to E (Change 16)
The program now updates the non-editable
values of F(T) when Site Class A-E is selected when the peak ground elevation
PGA value is changed, or the value of Sa(0.2) changes such that it
switches between from being greater than or less than 0.8 PGA, as per NBC
4.1.8.4.(4). Previously the values only updated when the Site Information box
was closed and reopened.
b) Upon Change of PGA for Site Class F (Change 10)
With Site Class F selected so the F(T)
values are editable, after changing F(T) then the peak ground elevation value
PGA, the F(T)’s reverted to their previous values.
c) Upon Return to Site Class F (Change 11)
When Site Class F is selected and F(T)
values are edited, then changing to another Site class so that other
non-editable values appear, and back again, the program now puts back the F(T)
values that were previously entered rather than zeroes.
d) Verification upon Exit (Change 26)
If Site Class F is selected, and the F(T)
values not changed from the default value of 0, the program now issues a
warning message asking you to enter non-zero values. If OK is selected, you return to the input dialog; If Cancel is selected, the changes are
reverted. Previously the program allowed you to save these values and generated
seismic loads based on the zero F(T)’s, generating zero seismic load of all
were zero.
The same functionality has been implemented
for when the NBC 2010 design code setting is selected and Fa or Fv is zero when exiting the box. Previously these values defaulted
to the those from the last site class selected; now zeroes appear when
selecting Fa or Fv.
4. Nonsensical Seismic Forces (Bug 3362)
On rare occasions one or more shearline forces
would be calculated with nonsensically high values. These values appeared in
the Shear Results table and were reflected in the storey shear and diaphragm
design forces in the Seismic Information
table. This rarely occurring bug due to unusual values of torsional rigidity
for flexible diaphragm design encountered in intermediate iterations and has
been corrected.
5. Torsional Analysis Report for Flexible
Diaphragm Wind Design (Change 55)
If a project is run such that torsional
analysis is required, then the inputs are changed such that it is not and run
again, the program retains the Torsional
Analysis Details from the previous run. Torsional analysis is not required
if the Rigid Analysis option is not selected in Structure Input view, and there
are only wind loads on the structure, as seismic loads require flexible
diaphragm torsional analysis.
6. Seismic Load Generation Details Formatting
The following minor
formatting changes have been made to the Seismic Load Generation
Details file.
a) Decimal Places for Sa (5.0) (Change 15)
Four decimal places were output for the value of Sa (5.0), the 5% damped spectral response acceleration in the Seismic Load Generation Details. Now it is output with two decimal places.
b) Extra Line (Change 18)
An extra line appearing between the line reading Equations (units = N,m) and the Equations in the Seismic Load Generation Details file has been removed.
c) Change in Subscripts for Distribution of Base Shear to Levels (Change
19)
The column headers hi, Wi and hi * Wi are now output as hx, Wx, hx * Wx in the Distribution of Base Shear to Levels table appearing in the Seismic Load Generation Details file. The change in subscript from i to x is because the subscript i is stated to be used for the level in summations in the Legend section, whereas x is for a particular level.
7. Wind and Seismic Procedure in Site Information
Table (Change 17)
In the Site
Information table of the Design Results, the words from and for appearing
beside the NBC wind and seismic load generation procedure reference have been
removed.
C: Input and Program Operation
1. Re-appearance of Plan View Input Forms (Change 37)
When
in Plan view and you close the input form, e.g. Opening Input, either by the exit button on the form window or by
the Input Form icon in the toolbar,
then go to another Plan view action, e.g. Roof Input, and return, the input
form for the original action now re-appears. Previously it remained invisible
and some users had difficulty making it reappear.
2. Crash on Corrupted or Empty Hold-Down Database (Bug 3375)
If the hold-down
database was empty or corrupted, a crash occurred on program start-up. The
program now re-installs the original database if it encounters a corrupt or
empty one.
It was possible to
avoid the crash by deleting the corrupted hold-down database file.
3. Log File Menu Item (Change 2)
The File menu item Log File has been removed as what was previously the log file is
now split into four text output files, none of which are referred to as “log
files”.
The following files
are now accessed from menu items in the View
menu.
Wind Load Generation Details
Seismic Load Generation Details
Torsional Analysis Details
Detailed Shearwall Design
Note that they also
have icons in the toolbar.
In the View menu the
word View has also been removed from Design Results View, for consistency
with these menu items.
4. Link to Video Tutorials in Help Menu
(Change 29)
An item Video
Tutorials has been added to the Help menu for the link http://cwc.ca/woodworks-software/support-and-training/canadian-tutorials/ which goes to the WoodWorks video
tutorials on the CWC website, where you will find numerous Shearwalls
tutorials.
5. Wall and Shearline Input Form
The following changes
were made to the operation of the Wall
and Shearline Input form
a) Standard Wall Input Box Overlap (Change 5)
While in the Standard Wall mode, the dropdown box with the list of Standard Walls overlapped with the input box to the right showing the name of the Standard Wall being edited, and when dropped down it obscured part of the name of the Standard wall. There is no longer any overlap.
b) Shearline Selection in Wall Input View (Change
24)
The Shearline input is now disabled if there is no choice other than Auto. This input allows you to select the shearline a wall belongs to if the walls are within the allowable shearline offset of walls defining two or more shearlines. As the default offset in the Design Settings is only 0.15m, this rarely occurs, and the use of this input was unclear to some users.
6. Disabled Worst-Case Rigid vs Flexible Diaphragm Setting (Change 54)
In the Design
Settings, the check box for Worst-Case
rigid vs flexible diaphragms was disabled and showing as selected if only
one of Rigid or Flexible Analysis was
selected in the Structure input. Now
it is shown as not selected (empty) in this case.
7. Dropdown Box Style for Wall and Opening
Hold-down Input (Change
82)
The hold-down model input in both wall and
opening view has been changed from an editable drop-list to a noneditable list,
as a hold-down typed into this input would not necessarily match with an
existing one in the database.
8. Tool Bar Menu Item Spelling
The
following spelling corrections were made in the items in toolbar dropdown menus
a) Drag Strut in Show Menu (Change 57f)
In the Show menu, under Forces, Dragstruts has
been changed to Drag Struts.
b) Irregularities in Go To Table Menu (Change 87)
In the Go To Table menu under Design Results, Seismic Irregularities had the misspelling Irregulairites.
c) Storey in Go To Table Menu (Change 21)
In the Go To Table
menu under Structural Data, Story
Information is corrected to Storey
Information.
9. Warning and Informational Messages
The following changes
were made to the text in messages:
a) Warning Message for Rounded Opening Input
Values (Change 48)
The warning message about opening input being rounded to the nearest snap increment, identified the input by long phrase that did not make sense in the context of the warning. It has now been abbreviated to briefly identify the input, e.g. Offset from edge. Square brackets around the input value have also been removed.
b) Loads and Forces Warning Message Misalignment
(Change 4)
The warning message when Loads and Forces view for the first time had misaligned bullet points. This has been corrected.
c) Irrelevant Messages in Status Bar (Change 9)
Irrelevant messages from other part of the program operation were displayed in the status bar at the bottom of the program window upon hovering the toolbar items Go To Table, Zoom Out, Zoom in, Undo, Redo and getting Started. These have been removed and nothing appears in the bar at this stage.
Shearwalls 10 ––
Design Office 10 – January 31, 2018
The following major features
are implemented for this version,
NBC 2015 – Wind
Load Generation
NBC 2015 – Seismic
Load Generation
5-and 6-Storey
Design
Improved
Irregularity Detection and Design
Linearized
Deflection Equation
Elevation View Improvements
The following is an
index of links to descriptions of all the changes.
A: NBC 2015 and CSA O86-14 Updates - General
1. Choice of Design Codes and Standards
3. Synchronization of NBC and O86 Editions
4. Design Code Clause References
B: NBC 2015 – Wind Load
Generation
1. Wind Load Generation Procedures and Methods
4. Pressure Coefficients Cp for Buildings of Any
Height
5. Pressure Coefficients CpCg for Low
Buildings
6. Internal Pressure Coefficient Cpi
1. Low-rise
Wind Loads for Multiple Blocks and Eccentric Ridge Lines (Feature 26)
6. Load Generation Details Output
7. Bug Fixes and Small Changes
D: NBC 2015 – Seismic Load
Generation
1. Design for Low Seismic Loads
3. Site Coefficients F(T) and Design Accelerations S(T)
4. Disallowed Irregularities for 5-6 Storey Wood Frame
Construction
5. Gravity-Induced Lateral Demand Irregularity Type 9
7. Period Ta for Single-storey Wood Structures
9. Overturning Reduction Factors J and Jx
10. Base Shear Increase for User-input Ta for 5-
and 6-Storey Buildings
11. One-storey Buildings with Large Diaphragm Deflection
E: Other Seismic Load
Generation
1. Period Restriction on Irregular Structures
2. Vertical Stiffness Irregularity Type 1
3. Weight (mass) Irregularity Type 2
4. Re-evaluation of Discontinuity Irregularities Types 3, 4,
and 5
5. Deflection Analysis for Detection of In-Plane (stiffness)
Irregularity Type 4.
7. Disallowed Irregularities for 5- and 6- Storey Structures
8. Load Generation Details Output
9. Bug Fixes and Small Improvements
F: Load and Force Distribution
1. Sign Convention for Torsional Analysis
2. Torsional Analysis Details Output
3. Bug Fixes and Small Improvements
G: Deflection Analysis and
Shearwall Design
1. 3-term vs. 4-term Deflection Equation (Feature 211)
3. Bug Fixes and Small Improvements
1. Zoom and View Settings (Feature 216)
2. Multi-storey Selected Walls (Feature 230)
3. Shading of Non-shear-resisting Segments (Feature 56)
4. Dimension Lines (Feature 79)
5. Display of Roof Line and Gable End (Feature 228)
6. Segment Numbers (Feature 77)
7. Bug Fixes and Small Improvements
2. Wall Depiction in Plan View (Feature 56)
3. Design Case in Plan View (Feature 83)
4. Bug Fixes and Small Improvements
1. Separate Torsional Analysis and Load Generation Output
3. Bug Fixes and Small Improvements
A: NBC 2015 and CSA O86-14 Updates 1 and 2 -
General
The program now
implements the 2015 National Building Code (NBC), but still retains the
implementation of design with the NBC 2010 as a user option.
1. Choice of Design Codes and Standards
In the Design Code drop list the Design procedures data group of the
Design settings, the choice CSA O86-14/
NBC 2010 has changed to CSA O86-14/
NBC 2015. The CSA O86-09/ NBC 2010 choice
remains unchanged.
This change is also
reflected in the output of the design settings, the About Sizer box accessed from the Help menu and in the Building
Codes box accessed from Welcome box, and the Welcome box.
The program now
indicates in the About Sizer box and
the Building Codes box that the CSA
O86-14 implementation now includes Update No. 1 from May 2016 and Update No. 2
from June 2017. The latter update caused some design code clause reference
numbers to change.
3. Synchronization of NBC and O86 Editions
The program now does
not allow you to generate loads with 2010 NBC and design with 2014 O86, or
generate with NBC and design with CSA O86-09.
If you try to do so,
when Design button is pressed, the
program offers a choice of cancelling design or regenerating loads.
4. Design Code Clause References
The references to the
NBC design code clause numbers in the input forms and screen messages, and in
warnings, design notes and other program output, have been updated to show the
2015 edition clause numbers when CSA
O86-14/ NBC 2015 is chosen as the design setting. It continues to show 2010
edition numbers when CSA O86-09/ NBC 2010
is chosen.
In determining which
NBC provisions should be included in the program and how existing ones were to
be interpreted and implemented, consideration was given to the changes in NBC
which allow 5- and 6-storey design for most wood structures, instead of the
previous limitation to 4 storeys.
The changed
provisions relate to permissible structures of combustible construction for
fire safety – 3.2.2.50 for residential use (Group C) and 3.2.2.58 for business
and personal service use 9 (Group D).
Note that neither the
building area limitations nor the height limits for these provisions are
checked by Shearwalls and it is your responsibility to ensure that your
building is within these limits.
The on-line Help in
the old Windows format containing references to the CSA O86-09 design code
provisions has been removed from the program. The newer Web Help showing CSA
O86-14 references is retained. It currently refers to the NBC 2010 design code
and has not yet been updated for Version 10 features and changes. This will be
done over time and updates posted to the web site.
The reference to NBC
now indicates that it is Division B, Part 4 that is used. The full name of the
Structural Commentaries is now given.
Under Mid-rise Wood
Construction:
- Design code provision reference numbers to NBC and CSA O86 are now given for all the line items about what is and isn’t included in Shearwalls.
- The line regarding increase in base shear due to manual T value has been moved from the section about what has not been implemented.
- The line regarding special requirements for certain shapes has been removed.
- A line about higher mode factor Mv and overturning reduction factor J has been added.
A section about Wind Load Generation has been added indicating that partial load cases from 4.1.7.9 and intermediate exposure factors Ce for change in terrain from 4.1.7.3.(5)(c) are not in the program.
B: NBC 2015 – Wind Load Generation
The changes described in this
section occur when NBC 2015
is selected as the design code edition in the Design Settings, unless
otherwise indicated.
1. Wind Load Generation Procedures and Methods
a) Design Setting
The Design setting for Wind load generation procedure has changed to Wind load generation method to avoid confusion with the static vs dynamic procedures, which are now so named officially.
The choices referring to Commentary Figures 1-7/8 and I-15 have changed to
NBC 4.1.7.5 – Other
buildings
NBC 4.1.7.6 – Low
buildings
b) Load Generation Details
i. Header
In the header to the Load Generation Details file (previously part of the Log file), now states that the Static procedure from NBC 4.1.7.3 is used (4.1.7.3) then refers to the 4.1.7.5 or NBC 4.1.7.6 method selection.
For both 2010 and 2015 NBC selections, the program now gives the C&C procedure used, as one of
2010 all-heights: NBC Commentary Figure I-15 using Cp*
2010 low rise: NBC Commentary Figure I-8
2015 all-heights: Figure A-4.1.7.5.(4)
2015 low rise: Figure 4.1.7.6.-B
ii. Code References
Throughout the report, all design code references now refer to 2015 provisions when the 2015 NBC option is selected.
c) Site Dialog
In the header section of the Site dialog, the program now refers to the Static procedure from 4.1.7.3, and that the external pressure coefficients (Cp or CpCg) and the reference height h come from 4.1.7.5 or 4.1.7.6 according to the method selected.
d) Torsional Analysis Details
In the Torsional
Analysis Details file (previously part of the Log file), NBC 4.1.7.5 and NBC 4.1.7.6 are now referred to instead
of I-15 and I-7.
Where it previously said Low-rise
Case A, it now says Case A (NBC
Figure 4.1.7.6.-A)
e) Wind Shear Results Table
References to NBC 4.1.7.5 and NBC 4.1.7.6 have been added to the legend to the Shear results table.
f) Dynamic vs Static Procedure
NDS 4.1.7.1 and
4.1.7.2 clarify and solidify the conditions under which the Dynamic Procedure,
which is not supported by Shearwalls, must be used. However, these Articles
still do not state what height is to be used in the 4:1 height to width ratio
used to classify a building as dynamically sensitive: the eave height, mean
roof height, or ridge height.
i. Input
This design setting giving the choice of eave, mean roof, or ridge height has been renamed to indicate that it applies only to the classification of buildings in 4.1.7.2. All other heights have been clarified by NBC 2015.
ii. Warning
The warning message when this ratio has been exceeded has been modified to include references to 4.1.7.2.(2)(c) and 4.1.7.1.(3).
The definition
reference height h, used for the calculation of exposure factors Ce
and Cei has been moved from 2010 Commentary I 7 and I 8 to
4.1.7.3.(6) and 4.1.7.3.(7), respectively. Previously it was derived using an
ill-defined building height H, but this height has now been precisely given in
most cases as the mid-height of the roof.
The changes listed below apply to both the NDS 2010 and NDS 2015 design
code selections.
a) Criterion for Choosing Method
A literal reading of 4.1.7.3.(6)(a) could lead to using exposure factors for buildings less than 20 meters and least plan dimension, even if Low buildings is not selected as the wind generation method. However, 2010 Commentary I-7 bases the choice of reference height on the definition in I-26 of low-rise buildings, and we do not believe it was the intention of NBC to change this.
Therefore, the use of 4.1.7.3.(6)(a) is dependent on the user selection of the 4.1.7.6 – Low buildings method, and 4.1.7.3.(6)(b) on 4.1.7.5 – Other buildings, not on the actual dimensions of the building.
b) MWFRS Method – Buildings of Any Height
(4.1.7.5)
i. Leeward Surfaces
Previously, the program was using ˝ the eave height for all leeward surfaces (walls, roofs, and gable ends); now it uses ˝ the building height, which is ˝ the ridge height.
ii. Windward Roof Surfaces and Gable Ends
NBC 4.1.7.6.(3)(a) refers only to windward walls and no guidance is given for roofs. As the adjacent clauses refer to “surfaces”, and NBC 2010 I-7 referred to windward “faces”, we have assumed that the intention was that windward roof surfaces be treated the same way as walls.
Previously, the program was using the ridge height for windward roofs and gable ends. It now evaluates the pressures at increments of height, and computes a weighted average of the pressure which takes into account the diminishing width of hip panels, gable ends, and side panels on hip roofs. The height z reported is the centroid of the force distribution, i.e., the z at which the pressure is the same as the averaged pressure.
c) MWFRS Loads – Low Buildings (4.1.7.6)
No changes were
made to the calculation of reference value h for low-rise buildings’; it is
still the greater of ˝ the
d) C&C Loads
i. External Pressures
There has been no change to the reference height for external pressures for C&C loads, it is still taken as the height at the top of the building level.
ii. Internal Pressures
Previously, the program was using the same reference height for internal pressures Cei as for external pressures Ce. Now it uses the greater of 6 meters or ˝ the ridge height, as per 4.1.7.3.(7),
e) Load Generation Details
In the Load Generation Details output, the reference height for internal pressures is now shown above the C&C loads table, where the mean roof height was previously shown. Mean roof height has been removed as it is not relevant to C&C loads.
The definition of
the reference height in the Legend has been changed to reflect the new design
code reference.
The equations for
wind pressures in NBC 2015 4.1.7.3.(1) and (3) include a new topographic factor,
Ct, defined in 4.1.7.4, which is algebraically identical the
procedure in 2010 NBC which uses modified exposure factor Ce*
and gust effect factor Cg* in place of Ce Cg,
where Ce* is defined in Commentary I-14 and Cg*
in Commentary I-21.
a) Ct Calculation
The program was modified to calculate Ct
independently rather than modify Cg
and Ce in order to display these values in the program
output when NBC 2015 design is selected.
b) Reference Height
The NBC 2015 has
made it more evident that the height used for the Ct factor is
always the height above the ground, z, whereas the Ce factor may
have different heights depending on the building surface and the wind load
method employed. In calculating Ce* for NBC 2010, the program had
been using the same reference height as used in the Ce calculation.
The program now
uses the height z above the ground for both the Ct factor for NBC
2015 and Ce* in 2010. This is
the weighted average height over the surface for MWFRS loads, and the height a
building element at the top of a level for C&C loads.
c) Low-rise Loads
The procedure for
determining a modified gust effect factor for low-rise combined CpCg
from 2010 Commentary I-21 has been removed for 2015, as it is no longer
necessary.
d) Averaging
NBC 4.1.7.3.(2) says that pressures are to be averaged
over the building surface. Previously the program had been integrating C e*
/Ce over the surface then multiplying with the average Ce.
then calculating the gust effect factor Cg* using average Ce*
and Ce.
Now the program
integrates the value Ce (z) Ct(z) over the whole
surface. The difference in these two approaches can be expected to be quite
small.
e) Output
In the Load Generation Details file (previously part of the Log file)
- A definition of Ct has been added to the legend, with 4.1.7.4. reference.
- A definition of z for topographic factor height has been added to the legend.
- Definitions of Lh, Hh, and x have been added to the legend.
- The equation for the topographic factor Ct is shown in the Equations section.
- The values of Ct for each load are shown in a column in the load table.
- The height z corresponding to the average Ct is shown in the load table for each load.
- The asterisks in Ce* and Cg* when there is a topographic effect have been removed from the load table headers.
f) Other Changes
For both the NBC
2010 and NBC 2015 design selections, the symbols Hh, Lh, and x have been added to the Height, Length and From crest inputs. The units (ft. or m) now
appear only once in the data group title.
For the NBC 2015
selection only, 2-D Ridge will
be renamed 2-D Hill, to reflect the
change in the design code nomenclature.
4. Pressure Coefficients Cp for
Buildings of Any Height
In NBC 2010, pressure
coefficients Cp for buildings of any height were found in Commentary
I-29 and Figure I-15; in NBC 2015 they are in a new section, 4.1.7.5, and shown
in Figure A-4.1.7.5.(2)
and (3) for MWFRS loads and Figure A-4.1.7.5.(4) for C&C.
Previously, the
building surfaces were referred to as “walls”, not they are called “faces”,
implying the projected surfaces of roofs are treated as walls.
a) H / D Ratio
Previously, the program was using the ridge height for roof loads and the eave height for walls and gable ends when determining the height-to-depth (H/D) ratio. It now uses the same building height for walls, roof panels, and gable ends on the same face of the structure. The height used is the ridge height for faces perpendicular to the ridge, and the mean roof height for faces parallel to the ridge. For flat roofs, it is the eave height.
This change is made for both NDS 2010 and NDS 2015 design setting selections.
5. Pressure Coefficients CpCg
for Low Buildings
In 2010, pressure
coefficients CpCg for low-rise buildings were found in
Commentary I-27 and Figure I-7 for MWFRS loads and in Commentary I-28 and
Figure I-8 for C&C loads; in NBC 2015 they are in a new section, 4.1.7.6,
and shown in Figure 4.1.7.6.-A, for MWFRS loads and Figure 4.1.7.6.-B for
C&C loads.
There is no
substantive difference in the generation of wind loads using these provisions,
but the limitations on low-rise buildings given in Commentary I-26 vs
4.1.7.6.(1). NBC 2010 said that said that the coefficients are most appropriate
for buildings with height/width (H/W) ratios less than 0.5, and must be used
for H/W less than 1.0. NBC 4.1.7.6.(1) includes only the 1.0 H/W limitation,
a) Height used to Define Low Buildings
The extensive use
of “mid-roof height” in NDS 2015 leads us to believe that is what is intended
as H in the H/W ratio. Therefore, the program no longer uses the height
you select in the Design Settings to determine this, and always uses the mid-roof height.
This change is made for both NDS 2010 and NDS 2015 design setting
selections.
b) Width used to Define Low Buildings
For buildings with varying widths on each level, the program previously determined the width of the structure by taking the largest extent in each direction of any of the levels on the structure, then using lowest value of the NS and EW dimensions so determined. Thus, a structure with a large podium base and a narrow tower would use the base as the width of the structure.
To avoid this situation, the program now uses the average dimension of all levels on the structure in each direction, then the lesser of the two directions.
This change is made for both NDS 2010 and NDS 2015 design setting selections.
c) Warning Messages
Warning messages
shown when using the low buildings for H/W ratios between 0.5 and 1.0 have been
removed. Those for 1.0 and greater have been modified to show NDS 2015
references.
6. Internal Pressure Coefficient Cpi
In NBC 2010, pressure coefficients Cpi were found in Commentaries I-30 and I-31; in NBC 2015 they are in NBC 2015 4.1.7.7. The three categories for were previously called Category 1, Category 2, and Category 3, but now Table 4.1.7.7. has a column called Building Openings, with the associated Cpi values. The word “category” is no longer used.
a) Input
The Site Dialog
input in the Internal Pressure data
group is renamed to Openings from Category.
The choices that
were previously
1. Exceptionally sealed
2. Ord. closed openings
3. Large open openings
are now
Uniform,
small, < 0.1% area
Non-uniform,
resistant, closed
Large,
often open
This change is
also reflected in the Site Info echo in the output report.
b) Load Generation Details
In the Load
Generation Details report, longer descriptions are given, as follows:
Uniformly distributed,
small, less than 0.1% of total surface area
Non-uniformly distributed;
if significant, wind-resistant and closed
Large, likely to be open
during storms
1. Low-rise Wind Loads for Multiple Blocks and
Eccentric Ridge Lines (Feature 26) *edited extensively
after first written for 10.2
The method of
determining external pressure coefficients CpCg for
low-rise structures from NBC 2015 4.1.7.6
and Figure 4.1.7.6.-A (or NBC 2010 Commentary Figure I-7) assumes
symmetric, rectangular structures. They
are based on boundary layer wind tunnel studies of buildings of that shape,
verified against full scale measurements (NBC Commentary I-20).
As relatively few
low-rise structures have such a regular shape, Shearwalls now extends this method to buildings with multiple
blocks and/or eccentric ridge lines.
When two blocks intersect such that the slope
of a portion of a roof can be formed either by either the side panel of one
block or the end panel of the other, such as one roof framing into another to
form an L-shape, the manner in which the building is modelled does not affect
the wind loads generated because end hip panels are treated as side panels
using the other load case.
i. Walls
The area of exterior walls beneath a sloped roof are considered to “have” the slope of the roof for the purpose of Case A (transverse) load generation, which depends on roof angle. If there is a hip end in the Case B (longitudinal) direction Case A coefficients are used on the wall beneath the hip end, the same as the rest of the building face formed by the side of the other block.
ii. Roofs
A hip end panel in the same plane as a side panel on another block has the co-efficient from the same load case as the side panel, so it is equivalent to the situation where the side panel from one block forms the roof on the entire face and the other block joins that block without forming a hip end.
b) Differing End Panels
Previously the program disallowed structures
for which the hip ends on opposing ends of a block had different slopes, or
there was a hip on one end and a gable on the other. Now these structures are
allowed, and the coefficients used on the roof panels and the walls below the
panels are based on the angle of each roof panel.
c) Eccentric Ridge Lines
Previously the program disallowed the case
of an eccentric ridge line with different slopes on either side of the ridge.
Now this case is allowed, and the coefficients used on the side roof panels and
the walls below the panels are based on the angle of each roof panel. This
applies to each roof on a structure with multiple blocks.
d) End zones
End zones are created at the ends of each
roof block. This conservatively creates
higher end zones loads in areas of the building, such as interior corners and
the portion of a building face where one block meets another, that should not
experience higher wind loads due to end effects. These loads can be manually
edited to have the same value as the non-end-zone loads on that face. It is
left as a future improvement to the program to eliminate these extra end zones.
e) Height-to-Width Ratio for Building Limitations
The calculation to determine the width for
the height-to-width limitations for this method in NBC 4.1.7.6.(1)
considers the maximum extent of all walls on the structure rather than the
extent of a single block.
f) Screen Warnings
The error messages that appeared after Generate Loads was invoked saying that
load generation was not possible due to unequal hips, eccentric ridge lines, or
multiple blocks, have been modified to provide warnings and suggestions for
these reasons, but to indicate load generation will proceed.
g) Load Generation Details
In the Load
Generation Details output:
i. Header Note
A note in the header section of the Load Generation Details output indicates that the building does not conform to strictly to NBC 2015 Figure 4.1.7.6.-A or NBC 2010 Figure I-7 for the following reasons, included if applicable to the structure – multiple blocks, eccentric ridge lines, hip roof construction, or unequal hip or gable ends.
ii. Load Table
There are now load tables for each block for multiple block structures, where previously only one table was possible.
h) Torsional Analysis Details
If there are multiple blocks of which any
two have orthogonal ridge lines, then both Case A and Case B loads can exist in
the same direction on different blocks.
In this case, in the Torsional
Analysis Details output where it otherwise says Low-rise Case A or Low-rise
Case B, it says Low-rise Case: and
then Wind Generally North-South or Wind Generally East-West.
For orthogonal ridge lines, where the
section for Case A previously had results for only one load direction, there
are now results for both directions.
Previously, Shearwalls
analyzed low-rise wind loads from NBC 2010 Commentary Figure I-7 (NBC 2015
Figure 4.1.7.6-A) by considering pressures in the E-W and N-S directions independently
and ignored the torsional forces in the orthogonal direction.
However, Note (1) to these
Figures says that the building must be designed for “all wind directions”,
and that Load Case A and Load Case B are the separate cases for which loads
“including torsions” must be generated.
Shearwalls now includes loads due to pressures in both directions in the torsional
analysis routine simultaneously, so that torsional forces from E-W loads are
considered when determining N-S forces, and vice-versa.
Note that it is only Case B that has
simultaneous pressures in both directions.
a) Calculations
In the torsional analysis routine, the program now calculates the torsion T in the equation
Fti
= T Ki li
/ (Jx
+ Jy)
as Tx + Ty for both
directions, when previously it Tx
was used for one direction and Ty for the other. Refer to the Torsional Analysis Details
output for the definitions of these variables.
b) Torsional Analysis Details Output
In the Torsional Analysis Details file, for load Case B
-
A note has
been added to the top saying explaining the simultaneous design, referring to
Note 1 in the Figures.
-
The
Concentrated Load F, Center of load Cl and Eccentricity etx values are shown in a table at the top for both
directions, rather than separately for each direction. F and Cl now show
subscripts for direction, e.g. Fx and Cly
-
The
equation of torsions has been modified to show both directions rather than one.
The program now
allows you to show in Plan View the low-rise loads for Case A in the
longitudinal direction and Case B in the transverse direction, as these are the
cases that will ordinarily govern for design.
a) Single vs. Multiple Block
This option is
available only for single block structures, because for a particular wind
direction, multiple block structures can have Case A at the end some blocks and
Case B for others, and similarly for the sides.
b) Show Menu
The option Case A Side, Case B End appears after the Case A and Case B under Wind Load Case in the Show Menu.
c) Plan View Arrows
The large hollow arrow angled to show the general wind direction has been replaced by two orthogonal arrows in the N-S and E-W directions for this choice.
d) Torsional Analysis
Note that these loads are not to be considered to have been generated simultaneously, and the set of loads shown is not used to generate any torsional analysis case.
The following changes have been made to the Show menus when Wind design is selected.
a) Orientation
For wind loads, Orientation has changed to MWFRS
Direction.
b) Wind Direction
When the Other buildings – 4.1.7.5 wind method is
selected, Load Direction is changed
to Wind Direction.
c) Wind Load Case
i. Activation When Not Relevant
When the Other buildings – 4.1.7.5 wind method is selected, the wind load case this option is now disabled. Previously the selections were available but had no effect. This happened even when seismic loads were showing.
ii. Case A and Case B Nomenclature
For single block structures, Case A or Case B appear in brackets beside the wind direction, according to the ridge direction of the structure.
5. Load Generation Details Output
In addition to
changes for new or modified features described elsewhere, numerous small formatting
improvements and insertions of key information have been added to the Load
Generation Details output. The following give the more important changes when
NBC 2010 is selected; and the corresponding improvements made using NBC 2015
provision reference numbers when that option is selected.
a) Header and Footer
-
The title,
Wind Load Generation, has been set to all capitals to make it stand out from
the Seismic Load Generation section that appears later.
-
Add spaces
to better delineate the start of the seismic load generation after wind load generation.
b) Site Information
-
Add
internal gust factor Cgi, as it is entered in the Site information dialog.
-
Add units
(m or ft.), to the hill height, length, and above crest topographic values
(Change 242)
c) Legend
-
Add
reference to 4.1.7.1.(4) and App. C for velocity pressure q.
-
Clarify
that importance factor is ULS (ultimate limit states).
-
Correct
reference for Ce from 4.1.7.1 to 4.1.7.1.(5).
-
Clarify
that reference heights h come from Commentary I-7(c) as well as I-7(a) and I- 7(b).
-
Give the
reference to Figures I-7 for the values of low-rise zone Zn and Windward
corner WC.
-
For NDS
2015 option, there are now 2 lines for Cp, one for MWFRS loads and
one for C&C loads, showing different design code references.
d) Equations
-
Clarify
that C&C wind pressure is from 4.1.7.1.(1) and (3), not just (3).
-
Add the
missing factor 0.7 to the equation for rough terrain exposure factor Ce.
-
Add the
words “Exposure factor” before the expression for Ce.
e) Load Table
-
Add MWFRS
and C&C to the header line of the tables, and remove the repetitive first
columns showing these labels. (Change 233)
-
For
C&C loads, the mean roof height no longer appears above the table, as it is
not relevant to the calculations; instead the value of the reference height h
used for Cei calculations is shown, as that had not been output anywhere previously
(QA Item 12e).
-
In the low-rise
C&C table, the column for internal exposure coefficients Cei was
showing 1.0 regardless of the actual Cei value. It now shows the correct Cei value
(QA Item 12a).
-
In the
low-rise C&C table, the CpCg column was showing the
difference between external CpCg and internal Cpi
* Cgi. It now shows just external CpCg as Cpi
and Cgi are shown elsewhere in the table (QA Item 12d).
-
The
Tributary Height column has been removed for C&C loads, as it has no
meaning for these loads and showed random values. (QA Item 64)
6. Bug Fixes and Small Changes
a) Windward Low-Rise C&C Loads (QA Items 12b
and 12c)
For windward
low-rise C&C loads program was using the pressure and gust co-efficient CpCg
for leeward direction, and internal pressure coefficient Cpi for
positive pressures when it should have been using negative pressures. The
incorrect coefficients were listed in the Load Generation Details output.
This has been
corrected, and different windward and leeward coefficients are created.
For out-of-plane
sheathing design, the program now determines the worst case of internal
positive pressure and leeward loads, and internal negative pressure and
windward loads. As it is only rare cases that the windward loads govern, this
had little effect on sheathing design. Nail withdrawal design is not affected.
b) Windward C&C Load Magnitudes (Change 237)
Windward C&C
loads were being generated with the same magnitude as leeward ones, i.e., with
differing interior and end zone magnitudes. They are now being generated with
the correct magnitudes.
Windward C&C
loads affect only sheathing design (not nailing), and this change has little
design effect as end zone leeward (suction) loads almost always govern
design.
c) Low-Rise MWFRS Pressure/Gust Factor CpCg
for Topographic Effect
For low-Rise
MWFRS loads with a topographic effect, the program was not including the Cg*
component from as per NBC 2010 Commentary I-21, which says you are to multiply
CpCg by Cg* and divide by Cg.
It was doing this
correctly for C&C loads.
Since Cg*
for topographic effect is diminished relative to Cg, this was a
conservative bug, and has been corrected for the NDS 2010 design code option.
NDS 2015 no longer includes this calculation.
d) End Zones Under Low-rise Hip Roofs, Case B (QA
Item 90)
For walls under
hip roof ends using the low-rise procedure and a longitudinal wind direction
(Case B), end zones were not being created. This has been corrected.
e) End Zones Under Low-rise Hip Roofs, Case A (QA
Item 90)
For walls under
hip roof ends using the low-rise procedure and a parallel-to-ridge wind
direction wind direction (Case B), end zones were not being created. This has
been corrected.
f) End Zones Under Low-rise Hip Roofs, Case B (QA
Item 91)
For walls under
hip roof ends using the low-rise procedure and a perpendicular-to-ridge wind
direction (Case A), end zones were created with a 1-meter width rather than 6
meters, according to 4.1.7.6.A Note 6. This has been corrected.
g) Note for Walls Under Hip Ends (QA Item 90)
The note
indicating that hip ends are treated as side panels in terms of low-rise
coefficients has been modified to indicate that the walls under the hip ends
are also use the same load case as the roof, that is, the one for side panels.
A reference to 2001 AWC Wood Frame Construction Manual,
Table 2.5A has been added to
explain this.
h) Saving of Height Option for b (Change 238)
The Design
Setting which is now called Height for
Wind Classification is now saved to the project file, it hadn’t been
previously.
i) Hip Roof Options in Load Generation Input (QA
Item 43g)
The disabled
options for hip roof load generation pertain to the USA version of the program
and have been removed completely for Canada.
j) Topographic Factor Above / Below Crest in Site
Info (Change 245)
When Below crest is selected in the Site
Information dialog box, the Site Location in the Site Information of the Design Results
output says Downwind of the
crest. When it is below the crest, it
should be Upwind, according to Figure
4.1.7.4, and when it is above the crest, it should be Downwind. This change has been made.
k) Load Generation Log File Wind Load Header (Bug
3084)
n the Load
Generation portion of the log file for the All-heights wind load generation
method, the line of “------“s was printed at the tail end of the Wind Load
Generation header instead of on a new line. This has been corrected for the new
implementation in the Load Generation Details file.
l) Wind Direction in Loads and Forces Settings (Bug 3240)
In the Loads and Forces settings, the check boxes labelled Southwest, Northeast, Southeast, Northwest have been changed to show Wind from Southwest, Wind from Northeast, etc.
An explanatory note has been added to the Torsional Analysis Details output suggesting manual approaches to implementing load cases B, C, and D from NBC 2010 4.1.7.3 and NBC 2015 4.1.7.9. These cases are not generated automatically by Shearwalls, and would have an effect only on rigid diaphragm torsional forces.
n) Delay in Generating Wind Loads with Topographic Factor (Bug 3251)*
For calculation of the loads that include a
topographic factor from NBC 4.1.7.4, the
program was performing the calculation of the Ce, Ce* and Cg* factors at
a thousand times as many heights on the surface of the building as was
intended, causing a 1-3 second delay when generating loads. This has been
corrected.
D: NBC 2015 – Seismic Load Generation
The changes described in this
section occur when NBC 2015
is selected as the design code edition in the Design Settings, unless
otherwise indicated.
1. Design for Low Seismic Loads
NBC 2010 4.1.8.1.(1)
said that the seismic analysis using the Equivalent Static Procedure was not
needed for sites with S(0.2) less than 0.12. This provision has been removed, and replaced with a method in 4.1.8.1.(3)-(15) to
be used when a set of conditions for low seismic loading in 4.1.8.1.(2) is met.
This method tends to create larger seismic loads than the Equivalent Static
Procedure; its advantage is simplicity. It is not implemented in Shearwalls.
a) Message Box
Upon design, a
message box used to appear when S(0.2) was less than 0.12, asking you if
you wished to proceed with seismic load generation. This has been replaced by a
message that informs you of the simplified procedure, its limitations, and that
it produces higher loads. the program proceeds to design with the Equivalent
Static Procedure.
2. Seismic
Data
The following
pertains to the Table C-2 of Appendix C of NBC 2010 and Tables C-2 and C-3 of
NBC 2015 that give climatic and seismic data for all significant Canadian towns
and cities, which are selected via the default settings in Shearwalls.
a) Peak Ground Acceleration
The program
now includes the values peak ground acceleration (PGA) in the software data as
the NBC 2015 Equivalent Static Force Procedure now requires them.
b) Sa(5.0)
The program
now includes the spectral acceleration Sa(5.0) as it is now needed
to calculate the ratio S(5.0) / S (0.2) to determine higher order factor Mv and
overturning factor J. ). It otherwise
corresponds to buildings much higher than those designed in Shearwalls.
c) Spectral Acceleration Values
The values of Sa(0.2), Sa(0.5), Sa(1.0), Sa(2.0) have been
changed to correspond to those in NBC 2015. Virtually every value has changed,
many significantly.
3. Site
Coefficients F(T) and Design Accelerations S(T)
This section pertains
to the calculation of design spectral acceleration S(T) in 4.1.8.4 Site Properties, which is then used in
the Equivalent Static Force Procedure in 4.1.8.11.(2). It is calculated by:
NBC 2010: S(T) = Sa(T)
* Fv (Sa(T=1.0), Site Class)
NBC 2015: S(T)
= Sa(T) * F(T, PGA, Site Class)
where
-
site
coefficients F(T), Fv and F are determined from NBC tables,
-
period T
is calculated by the program or entered by the user,
-
Site Class
is entered by the user,
-
PGA and Sa
(T) are seismic data from Appendix C stored for each city and entered either
directly or by selecting a city.
a) Input
PGA, Sa(5.0) and five values of F(T) have been added to
the Site Dialog input. The fields Fa and Fv were removed. Like Fa and Fv,
F(T)’s are only active for Site class F.
b) PGA ref
The calculation
of PGAref = PGA * 0.8 if Sa(0.2) / PGA < 2.0
from 4.1.8.4.(4) has been added.
c) Fa and Fv
As per NBC 4.1.8.4.(7), the program now sets the value of Fa to F(0.2). Although no longer needed in the calculation of S(T), it appears in the expression IEFaSa(0.2) that is still used in many places to classify the structure for the application of various rules, particularly for irregularities.
Fv is no longer needed by the program.
d) Calculation of S(T)
The calculation
of S(T) from NBC 2015 4.1.8.4.(9) is S(T) = Sa(T) F(T), whereas for 2010 4.1.8.4.(7) it was S(T) = Sa(T) Fv
NBC 2015 Tables
4.1.8.4.-B to -E for F(T) have been entered into the program. For tables of
F(T) for periods on either side of the actual period Ta, the program
determines F(T) based on site class and PGAref, interpolating on
intermediate values of PGAref.
Linear interpolation is then used to determine the value of F(Ta), and it is also used to determine Sa(Ta). S(Ta) is then determined via F(Ta) Sa(Ta).
For T < 0.2 s,
the NBC 2015 now takes the maximum of F(0.2)Sa(0.2) and F(0.5)Sa(0.5),
whereas it used to just use F(0.5)Sa(0.5). This has been
implemented.
e) Load Generation Details
In the Load
Generation Details output, when NBC 2015 is selected as the design option,
i. Site Information
In the Site Information section which shows the user-input data,
- Sa(5.0) has been added
- A line showing F(0.2), F(0.5), etc. has been added if these have been input by the user because it is Site Class F
- Peak ground acceleration PGA has been added.
- Fa and Fv have been removed
ii. Legend
- The definition of Fv has been removed
- The definition of Fa has been changed, and it is indicated that it is now used for the IEFaSa(0.2) limit
- A definition of site coefficient F(T) has been added
- Definitions of peak ground accelerations PGA and PGAref have been added.
iii. Equations
- An equation for S(T) has been added, which also shows dependencies for site coefficients F
- An equation for PGAref from NBC 4.1.8.4.(4) has been added
iv. Total Design Base Shear Table
- A column showing F(Ta) has been added to the table
- S(Ta) replaces S(T) in heading
4. Disallowed Irregularities for 5-6 Storey Wood
Frame Construction
A new provision
4.1.8.10.(4) has been added to NBC 2015 for 5- and 6-storey wood-frame
buildings. If the IEFaSa(0.2) product is equal
to or greater than 0.35, then Type 4 In
Plane Discontinuity and Type 5 Out-of-plane
offsets irregularities are not allowed for these structures.
This was already
detected and reported by the software following an identical provision in the
BC Building Code, so the note under the Seismic Irregularities table has been
changed to refer to NBC rather than BCBC.
5. Gravity-Induced Lateral Demand Irregularity
Type 9
A new seismic
irregularity, Gravity-Induced Lateral Demand, Type 9, has been added to Table
4.1.8.6, with the associated provisions 4.1.8.10.(5)-(7). Note A-4.1.8.10.(5)
explains that this corresponds to such elements as inclined columns and floor
cantilevers, and involve yielding mechanisms like plastic hinges. This outside
the scope of the Shearwalls program and no attempt is made to detect this
irregularity.
a) Design Results Output
This irregularity
has been included in the Seismic Irregularities of the Design Results output,
giving the design code references, a note explaining why it is not applicable,
and a description below the table.
The maximum lateral
force V calculated in NBC 4.1.8.11.(2)(c) has is now derived from the maximum
of two equations as opposed to just one.
a) Calculation of Base Shear
For NBC 2010, the equation is
2/3 S(0.2) IE W
/ (RdRo)
For NBC 2015 it is the larger of this equation and
S(0.5) IE W / (RdRo)
b) Load Generation Details
In the Load Generation Details report (formerly
part of the Log file), this equation
has been added to the Equations
section.
For both the NDS 2010 and NDS 2015 options, the program no longer shows the notes indicating that the maximum shear has been used for design, and instead includes three base shear columns V in the Total Design Base Shear table – Vcalc, Vmax, and Vdes, giving the calculated base shear, the maximum base shear, and which of these has been chosen as the design base shear.
7. Period Ta for Single-storey Wood
Structures
A new provision for
single-storey wood structures, NBC 4.1.8.11.(4)(a), allows
for an increase in the period Ta calculated by the empirical formula
in 4.1.8.11.(3)(c) by an amount equal to .004L to where L is the shortest
distance between shear resisting elements.
4.1.8.11(c) says that
Ta computed using other methods but can’t be greater than 1.5 times that
from using 4.1.8.11.(4)(a). This compares to a factor of 2.0 using
4.1.8.11.(3)(c).
a) Calculation of L
L is calculated as the shortest distance between any two shearlines whose extents overlap by one inch or more. The extent of the shearline is defined as the distance between the ends of the extreme shear walls on the line, disregarding gaps in between. No attempt is made to determine whether shear resisting element extents overlap on a wall-by wall basis.
b) Calculation of Ta
For one-storey structures, the equation 0.05 hn3/4 + .004L is used for the approximate period Ta.
c) Restrictions on Manually Entered Period
Since this provision is “permitted” and not mandatory, the program checks whether the value input in the Site Dialog is greater than the greater of the two restrictions, that is 2.0 Ta using 4.1.8.11.(3) or 1.5 Ta using 4.1.8.11.(4).
d) Load Generation Details Output
In the Load Generation Details report, for one storey structures,
-
the equation for Ta in the Equations section includes .004L where
applicable
-
The
expression for Tmax shows the maximum of the two equations
-
A
definition of L is given in the Legend.
The program now
includes a calculation of higher mode effects Mv from NBC
4.1.8.11.(6), which is used in the calculation of base shear in 4.1.8.11.(2).
In previous editions
of the NBC, all Mv = 1 for all values of period T equal to 1.0 or
less, so that no building in Shearwalls could have a non-unity Mv. Table
4.1.8.11 of NDS 2015 has non-unity Mv values for T= 1.0 and values
of S(0.2)/S(5.0) > 20. Because a new column bas been added with values of
1.0 for T = 0.5, due to linear interpolation, non-unity values exist for these
ratios whenever the period is greater than 0.5.
Since a period of
twice the one calculated by empirical formula 4.1.8.11.(3)(c) is allowed by
4.1.8.11.(3)(d)(iii), any height above that corresponding to T = 0.25 using the
formula could have a significant Mv. Since that height is 8.5
meters, well below the highest allowable structure in Shearwalls the
calculation of Mv in the program is now required. In practice,
values of Mv greater than 1.0- will come into play primarily for 5-
and 6-storey structures that are newly permitted by NBC.
Note too that ratios
of S(0.2)/S(5.0) > 20 for which Mv > 1 occur in numerous
locations in Canada.
a) Determination of Mv
The values of Mv
are taken from the section for Walls,
Wall Frames SRFS from Table 4.1.8.11. Within the range of structures
allowed in Shearwalls, these values are identical to those for Other systems.
A separate Mv is determined for each orthogonal force direction, using period Ta and the ratio S(0.2)/S(5.0) to index Table 4.1.8.11.
i. Interpolation
According to Notes 1 and 2 of Table 4.1.8.11, interpolation should be done on Sa(0.2)/Sa(5.0) first, then on Ta, and Note 2 says to interpolate on S(Ta) Mv, not just Mv(Ta). So, if we define Sr as the ratio of Sa(0.2)/Sa(5.0), for a Ta between 0.5 and 1.0, we
-
use
interpolation on Sr to find Mv( Sr, 0.5 ) and
Mv( Sr,1.0 ).
-
calculate
the values S(0.5) Mv( Sr, 0.5 ), and S( 1.0 ) Mv(
Sr, 1.0 ).
-
interpolate
between them to find [S Mv ] ( Sr, Ta ).
-
interpolate
S between 0.5 and 1.0 to find S( Ta
),
-
Mv
( Sr, Ta ) = [ S Mv ] ( Sr, Ta ) / S
( Ta ).
b) Load
Generation Details Output
Mv had always
been in the Total Design Base Shear table, showing 1.0. The value is now shown
to 3 digits precision.
An expression
showing the dependencies of Mv has been added to the Equations section, for both NBC 2010 and
NBC 2015
9. Overturning Reduction
Factors J and Jx
Although values of
overturning reduction factor Jx less than 1.0 were possible for
previous editions of NBC, through interpolating between the value of 1.0 for
T=0.5 and the non-unity values for T =
1.0, such structures would largely be 5- and 6-storey buildings not previously
permitted by NBC. Furthermore, as per NDS 2015 Commentary J-165, J is intended
as a corrective to the overestimation of higher mode effects Mv as
regards overturning, and Mv was not in previous versions of
Shearwalls.
With the introduction
of Mv in this version of the software, the overturning effect
factors J and Jx have also been implemented.
As with Mv, non-unity J values occur only for Ta
between 0.5 and 1.0, but unlike Mv, the occur for any value of the
ratio S(0.2)/S(5.0).
a) Determination of J for Whole Structure
The values of J
are taken from the section for Walls,
Wall Frames SRFS from Table 4.1.8.11. Within the range of structures
allowed in Shearwalls, these values are identical to those for Other systems.
A separate J is determined for each orthogonal force direction, using period Ta and the ratio S(0.2)/S(5.0) to index the table.
As per to Notes 1 and 3 below the table, interpolation is done on Sa(0.2)/Sa(5.0) first, then on Ta.
b) Storey Factor Jx
For each level, and in each direction, a story factor Jx is determined using NBC 4.1.8.11.(8):
Jx = 1.0 when hx >=
0.6 hn
Jx = J + (1 – J)
hx / 0.6 hn when hx < 0.6 hn
hx is the height at the top of level x, and hn is the mean roof height.
c) Hold-down Forces
All hold-down
forces on a particular level and direction are multiplied by the factor Jx
for that level and direction. This is because hold-down forces in Shearwalls
are derived from the formula Mx / L, where Mx is defined
as in 4.1.8.11.(8) and L is the wall segment length.
d) Output
i. Load Generation Details
In the Load Generation Details report:
- definitions J and Jx have been added to the legend
- an expression showing the dependencies for J has been added to the Equations section
- The formula for Jx has been added to the Equations section
- A column for J has been added to the Total Design Base Shear table
- Columns
for Jx in each direction have been added to the Distribution of Base Shear to Levels
ii. Hold-down Design Table
The value of Jx is shown for each shearline in the Hold-down Design table. A definition appears in the legend beneath the table.
iii. Elevation View
Jx is shown in the Factors section of the legend in Elevation view.
10. Base Shear Increase for User-input Ta
for 5- and 6-Storey Buildings
A new provision in
NBC, 4.1.8.11.(12), calls for a 20% increase in base shear for 5 and 6 storey
structures for periods determined using 4.1.8.11.(3)(d), i.e., “other
established methods of mechanics using a structural model”, most commonly
Rayleigh analysis.
As an increase in T
results in reduced base shear, we assume that whenever you over-ride the period
determined using the empirical equation 4.1.8.11.(3)(c) by entering a larger
one in the Site Dialog input, 4.1.8.11.(3)(d) is being used and the 20%
surcharge is applied.
A decrease in the
perio12d is assumed to mean that you are just adjusting the height used in
4.1.8.11.(3)(c), as no advantage is accrued.
a) Calculation
For each
orthogonal direction independently, if the period Ta is greater than
that calculated by the empirical equation 4.1.8.11.(3)(c), a factor 1.2
is applied to the calculation of base shear V in
b) Load Generation Details Output
When applied, the
equation for V shown in the Equations section of the Load Generation Details
Output includes the 1.2 factor. In the unusual case that it is applied in only
one orthogonal direction, two equations are shown for V, one for each
direction.
11. One-storey Buildings with Large Diaphragm
Deflection
A new provision in
NBC, 4.1.8.15.(4) for single-storey structures with a wood roof diaphragm and
with Rd greater than 1.5, requires magnification of deflections
and/or design forces if the diaphragm deflection exceeds ˝ the storey drift of
the adjoining shear walls. This affects only large structures with a large
sufficient distance between shearlines to create large diaphragm deflection.
As Shearwalls does
not currently calculate diaphragm deflections, a warning is displayed for
structures of a size that is susceptible to this condition.
a) Detection of Condition
The check for this condition is made before loads are generated. For single-storey structures only, if the Rd value is greater than 1.5, the program will determine, in both directions, the shortest distance between shear-resisting elements, using the same algorithm as given above. For imperial units, if the distance is greater than 100 feet, and for metric, 30 metres, the building is considered susceptible.
b) Warning Message
If the condition is detected, a Yes, No, Cancel message box asks you whether you want to change Rd to 1.5. The actions taken are
Yes – Change Rd to 1.5 and generate seismic loads.
No – Continue to use the existing Rd and generate seismic loads
Cancel – Don’t generate seismic loads
E: Other Seismic Load Generation
1. Period Restriction on Irregular Structures
The program
previously assumed that there would be no periods greater than 0.5, so the
program did not check for the condition Ta > 0.5 or disallow
irregularities of Type 1-6 as per 4.1.8.7.(1)(c).
However, a period of
twice the one calculated by empirical formula 4.1.8.11.(3)(c) is allowed by
4.1.8.11.(3)(d)(iii), so any height above that corresponding to T = 0.25 using
the formula, or 8.5 meters, could have a Ta > 0.5. In practice,
5- and 6-storey structures now supported by Shearwalls often do have periods in
this range when calculated using methods such as the Rayleigh quotient.
The following applies
if Irregularities Type 1, 2 ,3, 4, 5, or 6 exist and if IEFaSa(0.2)
>= 0.35:
a) Irregularity Table Failure Column
if T >= 0.5 in the direction(s) for which the irregularity exists, the shearlines and direction(s)s that have these irregularities appear in the “Fails for” column.
b) Table Warning
If T >= 0.5 in at least one direction for which the
irregularity exists, a red warning message appears above the table indicating
that design has failed due to the irregularity.
The message saying that the program does not check for T > 0.5 has
been removed.
c) Screen Warning
If T >= 0.5 in at least one direction for which the irregularity exists, a screen warning message appears indicating that design results are not valid.
d) Notes
Notes appear
below the table indexed to the irregularities saying that seismic design is not
allowed using the Equivalent Static Procedure when T > 0.5, and it is if it
is less than or equal to 0.5.
e) Design Summary
If T >= 0.5 in at least one direction for which the irregularity exists, it triggers the note in the Design Summary saying that at least one irregularity violates design code provisions.
2. Vertical Stiffness Irregularity Type 1
The program now
detects the Type 1 Irregularity – Vertical Stiffness, which occurs when the
lateral stiffness of a storey’s SFRS less than 70% of that of an adjacent
storey, or 80% of the average of the three storeys above and below.
a) Detection
If the stiffness on any level is less than 70% of the stiffness on the level above or below, than the irregularity exists.
For those levels with 3 storeys either above or below (levels 1 and 4 in a 4- storey structure; 1, 2, 4, and 5 in a 5-storey structure, and any level in a 6-storey structure), the program determines average of the 3 storeys either above or below the level, and if stiffness on the level under consideration is less than 80% of that value, the irregularity exists.
b) Irregular for..
For the adjacent level stiffness, the Irregular for… column in the Seismic Irregularity Table shows the level with the reduced stiffness followed by the stiffer level e.g. 3,4.
For the average of 3 levels, it shows the reduced stiffness followed by the stiffer levels as e.g. 4,1-3
The Direction
shows E-W, N-S, Both,
or None.
c) Fails for…
If there is a
weight irregularity and T>=0.5 for at least one direction, and IaFaSa(0.2)
>= 0.35, the storeys appear in the Fails for column
d) Notes
The note saying
it is irregularity detection is not required for because it is not a
post-disaster building has been removed.
The existing
notes about the relevance of IEFaSa(0.2)
>= 0.35 or < 0.5 and T < 0.5
are included when irregular. If T >= 0.5 a new note says that Equivalent
Static Procedure is not allowed.
e) Design Not Valid Warnings,
If irregular, T >= 0.5 in at least one direction, and IEFaSa(0.2) >= 0.35, a screen warning message appears indicating that design results are not valid, a red warning message appears above the Irregularities table, and the Design Summary says that at least one irregularity violates design code provisions.
f) Description
The description
of the irregularity below the table gives the 70% rule and 80% rules and
explains the table columns.
3. Weight (mass) Irregularity Type 2
The program now
detects the Type 2 Irregularity – Weight (mass), which occurs when a level is
1.5 x more massive than an adjacent non-roof level, or a roof is 1.5 x as
massive as its adjacent level.
a) Detection
Table 4.1.8.6 refers to a storey, which is defined in NBC Division A, 1.4.1.2 as the distance from the top of one floor to the top of the floor above it. The roof is considered a separate storey.
On the other hand, the levels that are defined for apportioning seismic load are defined from the middle of the wall on one level to the middle of the walls on the level above. A roof is considered part of the upper level.
For irregularity detection, the program collects all the masses that are tagged as being on level 2, for example, but come from the lower portion of level 3, and includes them as storey 3 loads. It excludes masses from the roof and gable ends, which are on the uppermost level, from the upper storey, and creates a separate storey for these.
For multi-block structures, for mass from roofs on blocks with fewer levels than the highest block, the roof is added to the mass of the level above the highest storey on the block. For example, if Block 1 has 2 storeys and block 2 has 4 storeys, a roof on block 1 will is part of level 3.
Flat roofs and ceilings are part of the uppermost storey of the block they are on, not the roof level.
Snow masses are not included among the weights for this purpose.
b) Irregular for…
The Irregular
for… column in the Seismic Irregularity table shows the heavier storey
followed by the light storey, e.g., 3,4. The direction is always Both. If a heavy roof is one of the
storeys, the word “Roof” is used.
c) Fails for…
If there is a
weight irregularity and T>=0.5 for at least one direction, and IaFaSa(0.2)
>= 0.35, the storeys appear in the Fails for column
d) Notes
The note saying
it is irregularity detection is not required for Ta less than 0.5
has been removed. The existing notes about the relevance of IEFaSa(0.2)
>= 0.35 or < 0.5 and T < 0.5
are included when irregular. If T >= 0.5 a new note says that Equivalent
Static Procedure is not allowed.
e) Design Not Valid Warnings,
If irregular, T >= 0.5 in at least one direction, and IEFaSa(0.2) >= 0.35, a screen warning message appears indicating that design results are not valid, a red warning message appears above the Irregularities table, and the Design Summary says that at least one irregularity violates design code provisions.
f) Description
The description
of the irregularity below the table gives the 150% rule, defines a storey, and
explains the table columns.
4. Re-evaluation of Discontinuity Irregularities
Types 3, 4, and 5
Research into the
intention of NBC 2015 4.1.8.15.(5) (NDS 2010 4.1.8.15.(4)) has inspired a
re-evaluation of the approach taken by Shearwalls to this provision. This
clause states that elements supporting a discontinuous wall are to be designed
for forces equal to the lateral capacity of the SFRS components they support
rather than calculated forces. The intention is to protect the gravity force
resisting system from forces due to lateral loading, for example a lintel above
an opening that supports vertical element such as a column carrying a hold-down
force at the end of a discontinuous shear wall on the level above the opening.
In such a case, the column, lintel, hold-down, and other connections are to be
designed using the capacity of the discontinuous wall.
a) Relevant
Irregularities
Shearwalls previously applied this irregularity for Irregularities Type 3 - Vertical geometric, Type 4 - In-Plane Discontinuity (offset), Type 4 - In-Plane Discontinuity (stiffness) and Type 5 - Out-of-plane Offsets, The rationale for Types 3 and 5 was that a discontinuity must exist somewhere for these irregularities to exist, and for Type 4 - In-Plane discontinuity (stiffness) that the NBC 2010 Commentary J-205 (NBC 2015 J-208) referred to Type 4 irregularities in general.
Shearwalls now
applies this provision only for Type 4 - In-Plane Discontinuity (offset) and Type 5 - Out-of-plane
Offsets. Shearwalls detects an in-plane
offset whenever wall ends do not line up on adjacent floors, which is exactly
the type of discontinuity this provision is meant to address. Type 5
discontinuities occur when there is no wall below a wall on the level above,
which also creates a discontinuity at wall ends.
Stiffness
irregularities are irrelevant to the intent of this item so Type 4 - In-Plane discontinuity (stiffness) is no longer included. And although Type 3 - Vertical geometric implies a discontinuity must exist
somewhere, it is a general, statistical check which cannot be used to identify
where action must be taken. If Type 3 exists, then a Type 4 or Type 5 must also
exist somewhere, so the situation will be handled without the need to include
Type 3 in the solution.
b) Weak Storey
The program
previously reported a failure due to these irregularities if the capacity of
the entire SRFS on the floor below the one with the discontinuity was less than
the capacity of one with the discontinuity. This was based on a misconception
and has been removed from the program.
The program no
longer includes discontinuous shearlines in the Fails for column of the Seismic Irregularities table for this
reason, nor does it issue screen warnings for this failure or place a red
failure message above the table. The notes below the table have also been
modified.
c) Strengthening of Hold-downs
When an
irregularity was detected, the program automatically used shear wall capacity
as the design hold-down force on all shear walls on both the level with the
irregularity and the level below. This is an overly conservative approach, and
this automatic procedure has been removed from the program until we can develop
an algorithm to identify and strengthen only those hold-downs that require it.
d) Strengthening of Drag Struts
When an
irregularity was detected, the program automatically used shear wall capacity
as the design drag strut force on all shear walls on the level below. Instead,
the program should add the additional force due to capacity-based design
on the floor above as a surcharge to the diaphragm shear force used to
calculate drag struts on the floor below. The automatic strengthening of drag
struts has been removed until we can develop such a procedure.
e) Design Iterations
The need to
identify irregularities to apply the automatic strengthening of hold-downs and
drag struts necessitated an additional iteration of force distribution and
design in Shearwalls. This has been removed, which should lead to somewhat
faster design results.
f) Warnings and Notes
All screen
warnings have been modified to indicate that you must manually strengthen
hold-downs and drag struts at specific locations, rather than informing you
that the program has done so. The notes below the Irregularities table have
been similarly modified.
g) Design Settings
The asterisk
beside the Design Settings Drag strut /
Hold-down forces based on … Applied loads has been removed, along with the
note saying that shear wall capacity is used for discontinuities as per
4.1.8.15.(4).
5. Deflection Analysis for Detection of In-Plane
(stiffness) Irregularity Type 4
Due to the non-linearity in the nail
deformation term of the equation for deflection for shear wall deflection from
11.7.1.2, shear wall stiffness decreases as applied force increases. As a
result, Shearwalls previously identified a Type
4 In-Plane Discontinuity (stiffness) in NBC 4.1.8.6 based on a lower-storey
shear resisting element having less stiffness than an upper storey one even
when walls on the two storeys had identical construction.
As structural analysis for most materials
assumes a linear stiffness relation v = K δ, where v are forces, δ deflection, and
K a constant stiffness matrix, we do not believe it was the intention of NBC 4.1.8.6
to consider identically constructed storeys as having differing stiffness. The
program therefore uses the 3-term linearization of the deflection equation
introduced in this version (see G: 1 below), to determine the
deflections for Type 1 - Vertical Stiffness and Type 4 – In-plane Discontinuity (stiffness)
irregularity detection. It does so even when the non-linear 4-term equation is
used for deflection analysis for force distribution and storey drift.
a) Design Iterations
If you have selected the 4-term deflection equation option in the design settings (the default), an additional design iteration will be inserted before the existing iterations, using the 3-term deflection equation, for the purpose of detecting Type 1 and Type 4 (stiffness) irregularities. Another iteration is then performed for final design of the shear walls using the non-linear 4 term equation, during which all other irregularities are detected.
b) Tolerance
Testing revealed that small, unwanted
differences in stiffness still occurred for identical shear walls on adjacent
levels. A comparison tolerance of 1% was added which eliminated these
occurrences.
c) Description of Irregularity
The description of the Type 4 – In-plane Discontinuity (stiffness) irregularity beneath the Irregularity table has been modified to reflect this procedure.
a) Irregularity Names
Irregularity
names in the Irregularity table have been modified to conform more closely to
the nomenclature in Table 4.1.8.6. In
screen messages they have been expanded to show a less abbreviated name, and in
the descriptions below the Irregularities table, the full name as it appears in
Table 4.1.8.6 is shown.
b) Format of References
The format of
references to NBC provisions in the table has been modified to conform to NBC
protocol, e.g., 7-1c is now 7(1)(c).
Compound references change from e.g. 10-1,2b to 10(1),(2)(b).
Also changed
comma between two Sentence references to a semi-colon, to distinguish from
comma between Clauses.
c) Detected by Column
The Detected by column has been removed as
all relevant irregularities are now detected by the program.
d) Type 6 Irregularity Message (QA Item 52)
The screen
message indicating an Irregularity 8 was detected referred to an IESaFa(0.2)
value of 2.0 when it should have been 0.2. This has been corrected.
e) Weak Storey
Irregularity 6 Notes (QA Item 78n)
The notes pertaining to Weak Storey Irregularity Type 6 have been
reorganized and improved, giving references to NBC 4.1.8.10.(1) and
4.1.8.10.(2)(b).
f) Post Disaster
Note (QA Item 78o)
A reference to NBC 4.1.8.10.(2)(a) has been added to the note about
post-disaster buildings.
g) NBC References for IEFaSa
(QA Item 78l)
The notes that include IEFaSa(0.2)
>= 0.35 or < 0.35 N now include
references to NBC 4.1.8.7.(1)(a), 4.1.8.6.(3) and Commentary J-122.
h) Commentary Reference for Type 7 Irregularity
(QA Item 78d)
NDS 2010
Commentary J-156 (NBC 2015 J-150) has been added for Type 7
Irregularities.
i) Commentary Reference for Type 7 Irregularity
(QA Item 78e)
NDS 2010
Commentary J-207 was a mistake; it has been changed to J-205.
j) Commentary Reference for Type 7 Irregularity
(QA Item 78h)
NDS 2010
Commentary J-127 was a mistake; it has
been changed to J-128.
k) Commentary Reference for Type 7 Irregularity
(QA Item 78i)
NDS 2010
Commentary J-177-9 was a
mistake; it has been changed to J-171-3.
7. Disallowed
Irregularities for 5- and 6- Storey Structures
A new provision 4.1.8.10.(4) has been added to the NBC disallowing
Irregularities Type 4 In Plane
Discontinuity and Type 5 Out-of-plane
offsets for 5- and 6-storey structures when IEFaSa(0.2)
>= 0.35.
This had already been
implemented in Shearwalls based on an identical provision in the British
Columbia Building Code (BCBC). The note at the bottom of the Irregularities
table and the screen message that appears for this condition have been updated
to refer to the NBC and remove references to British Columbia.
8. Load
Generation Details Output
In addition to the
changes to the Load Generation Details output described elsewhere due to new or
changed features, numerous small formatting improvements and insertions of key
information have been made. The following gives the more important changes:
i. Header
-
The title,
Seismic Load Generation, has been set
to all capitals to make it stand out from the Wind Load Generation section that appears earlier.
ii. Site Information
-
Removed
the words Regular Structure. This was not
intended to be in the Canadian version and appeared even when the structure is
irregular
-
The
spectral accelerations Sa(0.2), Sa(0.50), etc., have been placed on one line
for compactness, rather than each one occupying its own line.
-
Similarly,
for the NBC 2010 option the Fa and Fv values have been
placed on one line, and they are now shown only for site class F (when they are input by the
user).
-
The
importance factor Ie is now shown only when input by user for hazardous category.
iii. Legend
-
Reorganize table to put long descriptions all on left side so that the
table fits within a printed page.
-
The
definition for T now says it is in seconds (s).
-
Remove SRFS from the definition for Rd
-
The
definition of hn now says that it is the top level, not just “level n”
-
For
subscripts x, “level analyzed” is used instead of “level x”
-
For
subscripts i, the word “levels in sum” is used instead of “level i”
iv. Equations
-
The units,
(N, m) have been added to the title
of the Equations section indicating
the assumptions used when calculating the equations. These units are always
metric regardless of what is used to display the output values.
-
Removed
the unit reference for the height hn used for T, as units have been
added to the table heading
-
Design
code reference numbers have been added for all the equations
-
An
equation for Vmax has been added (NBC 4.1.8.11.(2)(c))
-
For the
NBC 2010 option, an expression showing the dependencies of S(Ta) has been added
-
An
expression showing the dependencies for RdRo has been
added (NBC 4.1.8.9)
-
An
expression for Ta max has been added (NBC 4.1.8.11.(3)(d)(iii))
-
The
maximum Ft value is now indicated (0.25 V)
v. Total Design Base Shear Table
-
The table
has been renamed Total Design Base Shear, from Calculation of the total design base shear:
-
The data
are now displayed in a tabular format with headings, rather than as repeated
symbols, equal signs, and values.
-
Units have
been added to the title of the table showing the system used for the data
displayed, which unlike the units for the Equations
table can be metric or imperial and show kN rather than N.
-
Fa and Fv
values are now shown beneath the table, as they are ordinarily calculated by
the program and not user input. Fv appears only for the NBC 2010
option
-
The
importance factor Ie is now shown beneath the table, as it
contributes to the calculation and is not ordinarily input by the user.
-
Removed
information about distribution of loads to the levels from note about manually
entered seismic loads and forces.
vi. Distribution of Base Shear to Levels Table
-
Distribution of total design base shear to
Levels has been changed to Distribution of Base Shear to Levels
-
In the
table heading, the words Height and Weight have been changed to the symbols
hi and Wi, which are defined in the legend
-
The
information about top level Ft has been moved from a note at the top of the
table to be a separate line in the table
-
Numbers
are now right-justified so decimal places line up, and trailing zeros are no
longer truncated.
-
Added note
about distribution of manually entered seismic loads and forces.
9. Bug Fixes and Small Improvements
a) Importance Factor Input for Hazardous Category
(Bug 2718)
The Importance factor in the Site Information dialog for Hazardous importance category, which is
a value you can override due to Commentary J-110, would revert to the default
value of 1.3 when the Site Parameters Dialog was re-opened. This value was then
used for design unless it is changed.
This has been
corrected and the input of importance factor now persists.
b) Seismic Irregularity Type 6 Failure Criterion
(QA Item 65)
The program was basing the failure criterion of Seismic Irregularity Type 6 – Weak Storey on a value of IEFaSa(0.2) > 0.12 when it should have been 0.20 as per 4.1.8.10.(1).
c) Seismic Irregularity Type 7 for Post-Disaster
Buildings (QA Item 69)
Seismic
Irregularity Type 7 was not amongst the irregularities that provoked a failure
due to NBC 4.1.8.10.(2).(a) for
post-disaster structures, but it should be. This has been corrected.
i. Wind Load Cases
When seismic loads are selected, the Wind Load Case options are now disabled. Previously the selections were available but had no effect.
ii. Force / SFRS Direction
The Force Direction item has been renamed SFRS Direction, for consistency with the change to MWFRS for wind. SFRS stands for Seismic Force Resistance System
iii. Load / Force Direction
The Load Direction input has been renamed Force Direction, as the shearline and hold-down forces are the only things that could potentially change when an opposing direction is selected. Note that it is very rare that seismic forces differ in opposing directions and this set of options usually has no effect.
F: Load and Force Distribution
1. Sign Convention for Torsional Analysis
In the Torsional Analysis Details file,
distances such as center of load, center of mass, shearline location and
eccentricity have been based on a fixed co-ordinate system with its origin in
the southwest corner of the structure. S->N distances are positive, and
N->S are negative.
The
forces F, however, are based on the direction of applied force; for N->S
applied force, all values in the N->S direction are positive; for S->N
applied force, they are negative.
Some users find this confusing and wish to see
all values relative to the same fixed co-ordinate system. Other users, however,
wish to see positive shearline forces when they are in the direction of the
applied force, and this corresponds to the way they are presented in the Plan
view drawing.
Accordingly, we now offer a choice in the
Options settings of showing forces based on a fixed co-ordinate system, or
relative to the applied force.
2. Torsional Analysis Details Output
In the Torsional
Analysis Details output report (previously part of the Log file)
a) Accidental Eccentricity References
In the Torsional Analysis Details, the references to accidental eccentricities have changed:
- For flexible diaphragm seismic, it was J 178 from a previous design code edition, and is now J-172 for J NBC 2010 and J-178 for NBC 2015.
- For rigid diaphragm seismic, it mistakenly showed a wind reference, and now shows NBC 4.1.8.11.(11) for 2015 and NBC 4.1.8.11.(10) for 2010.
- For rigid diaphragm all heights wind, it said just 37 for 2010, now it is I-37. For low rise wind for 2015 it refers to NBC 4.1.7.9.(1)(a) and A-4.1.7.9.(1) Case A
b) Headers
i. Repeated Header Line (Change 236)
When wind loads only were on the structure, the torsional analysis section of the log file output had a repeated header line. The new Torsional Analysis Details file shows only one header in this case.
ii. Wind Load Subheading Under Flexible Seismic (Change 240)
A sub-heading for wind loads mistakenly appeared under flexible seismic design. It has been removed.
c) Flexible Seismic Explanation (QA Item 3a)
It has been made
clear that the explanation of the Fti calculation is an example in
one direction only.
d) USA ASD Reference (Change 239)
A note referred
to ASD load factors, which is a USA term. This has been corrected.
e) Concentrated Load Terminology (QA Item 45a)
The term Concentrated Load F has been changed to Total Load F, as the load is not
concentrated at a location.
3. Bug Fixes and Small Improvements
a) Nonsensical Hold-down Forces under Monoslope
Gable End (Bug 3217)
When a wall was underneath a gable end from a monoslope roof, the hold-down forces calculated were nonsensically large. This has been corrected.
a) Shearwalls have Equal Rigidity Setting
The Design setting under Shearwall rigidity per unit length… for Shearwalls have equal rigidity has been removed from the program, as it does not correspond to any physical situation. It is a vestige of the original, less sophisticated implementation of torsional force distribution and is no longer needed.
a) Force Distribution due to Unsorted Openings (Bug 2099)
Occasionally, after a complex set of user interface operations, wall openings could become unsorted internally and skew the distribution of forces on the shearline, also affecting shearwall design. This has been corrected.
b) Nonsensical Output of Diaphragm Force (Bug
3185)
Occasionally, one of the diaphragm force Fpx values in the Seismic Information table would show a nonsensically high number. This was a rarely occurring bug due to unusual configurations of program memory, and has been corrected.
c) Show Menu Items for Center of Load and Center
of Rigidity (Change 251)
The show menu items for center of load and center of rigidity were always disabled in Loads and Forces view, only becoming active in Load Generation view. This has been corrected and they are active in both views.
d) Center of Loads for No-load Cases (Change 251)
When there are no
loads in a direction, such as for low-rise wind load Case A, the program showed
the Center of Load in the direction without loads at the zero location, making
it difficult to notice. In this case, it has now been moved to where the Center
of Rigidity is located.
e) Overlapping Center of Load and Rigidity Symbols
(Change 251)*
When the center
of loads and center of rigidity are in the same place or close to it, the
symbols CL and CR now longer overlap.
G: Deflection Analysis and Shear Wall Design
1. 3-term Linearized Deflection Equation (Feature
211)
Shearwalls now offers
the choice of using the 4-term deflection equation in CSA O86 11.7.1.2 and a
3-term linearization of this equation. The linearization follows a formulation
in the AWC Special Design Provisions for Wind and Seismic, equation 4.2-1, for
shear wall deflection analysis in the United States.
a) Background
The 3-term equation is a linearization of the 4-term
equation, arrived at by combining the shear and nail slip equations in the
4-term equation using an “apparent” shear stiffness Ga. The linearization is achieved by setting the
non-linear occurrences of shear force v to the shear capacity of the shear wall
to render them constant. It is
therefore identical to the 4-term equation when the shear wall is at capacity,
conservative when below capacity, and non-conservative for shear walls that are
overstressed for design anyway.
The 3-term equation can be preferable because the process of equalizing
deflections on the shear wall segments by adjusting the forces apportioned to
each segment sometimes does not converge due to the non-linearity of the 4-term
equation, whereas the 3-term equation always converges to a solution. Furthermore, using the 4-term equation,
Irregularity Type 4 – In Plane Discontinuity (stiffness) from NBC
4.1.8.6 is detected for adjacent storeys even if they are constructed of
identical materials (see E: 5 above).
b) Design Setting
Note that the choices of Always and Never have been chosen to allow the future implementation of a hybrid design for which we allow the program to automatically change from 4-term to 3-term on individual shearlines if non-convergence is detected, especially using flexible distribution; however, for Version 10, the switch must be made manually and for all shearlines in the structure.
c) Deflection Calculation
The following terms in the two-term equation
are replaced by
i. Ga Calculation
The calculation of Ga for wind design uses the formula
0.75 is the serviceability (SLS) importance factor for wind design, and 1.4 is the load combination factor for wind design, IW is the ultimate limit states (ULS) importance factor for wind design. These factors are needed to adjust for the fact that deflections use SLS forces but shear walls are at capacity for ULS forces. Ls is the shearwall segment length.
For seismic design,
Conversion between SLS and ULS load factors is unnecessary, as they are all 1.0; only the ULS importance factor IE differs.
ii. Unblocked Factor
The unblocked factor Jub is applied only to the v value in the main deflection equation. not the vs and vw values in the calculation of Ga. Dividing v by Jub is equivalent to factoring the whole shear stiffness Ga by Cub.
iii. Non-linear Anchorage Equation
CSA O86 has a further non-linearity to those in the main deflection equation in 11.7.1.2, the elongation for anchorages, which is
Analogous
to the procedure for calculating Ga, this is
d) Deflection Convergence
Using the
linearized setting, the program is always able to equalize deflections for all
segments on a wall, except those cases that there is not sufficient loading to
allow the same deflection to be achieved in some segments as for other segments
in the line that have a relatively high constant deflection due to factors such
as gypsum wallboard nail slip. This happens only for lightly loaded shearlines.
e) Stiffness Irregularity Detection
Even when you
choose not to linearize the equation for load distribution and storey drift,
the linearized equation is used for the detection of Type 4 Vertical Discontinuities (stiffness) irregularities. Refer to E: 5 above for more d Using the linearized setting,
the program is always able to equalize deflections for all segments on a wall,
except those cases that there is not sufficient loading to allow the same
deflection to be achieved in some segments as for other segments in the line
that have a relatively high constant deflection due to factors such as gypsum
wallboard nail slip. This happens only for lightly loaded shearlines.
f) Output
If the Design Setting option to linearize deflections is chosen, the Deflection table shows only one deflection value called Shear defl, rather than separate shear and nail slip deflection. The Ga value is also shown, and the Vn and en values for nail slip show the values at shear wall capacity vs or vw used to calculate Ga
The legend at the bottom of the table has been modified to reflect these changes.
2. Hold-down Database Update (Feature 202)
The database of hold-down connections has been
updated to conform to the Canadian Limit States Design version of the Simpson
Strong-Tie Wood Construction Connectors Catalogue, page 83, as of January 17th,
2018. This is found at http://embed.widencdn.net/pdf/plus/ssttoolbox/oknkjgclgk/C-C-CAN2018.pdf.
a) Design Settings Table
i. Relative Rigidity Formatting
For consistency with other cells containing phrases rather than numeric data, Shearwall relative rigidity and Design shearwall force/length are now in sentence case rather than title case.
b) Shearline, Wall, and Opening Dimensions Table
i. Aspect Ratio (Feature 77)
The aspect ratio (shear wall height / length) of each shear wall segment is now shown in a column in the table next to the full height sheathing. It is defined in the table legend.
ii. Wall Order
Occasionally, walls would appear out of order in the table. This has been corrected.
ii. Dash Justification
The dashes that appear for fields that do not contain data are now center justified. (QA Item 24a)
f) Sheathing and Framing Materials Tables
i. Grade/Ply (QA Item 75c)
The table header Grade/Ply has been changed to Mark/Ply, as the OSB Table 9.3C with grades no longer exists. The legend item below has also been changed
ii. Mark/Ply Legend Item
In the Mark/Ply (formerly Grade/Ply) legend item (QA Items 75a and 75b)
- Removed obsolete reference to table 9.4D
- Refers to plywood plies and OSB panel mark, not just “mark” and “plies”.
- “see” note 8 is not “shown in” note 8
iii. Panel Mark in Note (QA Item 75e)
The words panel marking have been changed to panel mark in the note below the table.
iv. Numbered vs. Non-numbered Notes (75d)
The list of notes without numbers has been differentiated
from those with numbers, with the former headed by General
Notes: and the latter by Material-specific Notes.
c) Design Summary
i. Percentage Gypsum Note for 5- and 6- Storey Structures (QA Item 27)
The note about compliance with O86 11.8.8 which disallows gypsum contribution for 5- and 6-storey structures was mistakenly replaced with one about Rd and Ro values. This has been corrected.
ii. C&C Non-shearwall Nail Withdrawal Failures in Design Summary (QA Item 28)
When C&C nail withdrawal design failed for non-shearwalls, the Design Summary said under capacity walls were found but did not list them. This has been corrected.
d) Seismic Information Table
i. Reference in Seismic Information Warning Message (Change 248)
The words CSA O86 have been added to the reference 11.8.3.2 about overcapacity ratio under the seismic information, as most seismic provisions are from NBC, and there are no nearby references to O86.
e) Shear Design Table
i. Order of Wall Rows (Bug 2116)
Shearwalls were not always listed in order as they occur from west to east or south to north. This has been corrected.
f) Components and Cladding Table
i. Table Legend
The table legend has been improved to
- add design code clause references,
- correct typos,
- clarify when end zone or suction pressures are used,
- say that 24” spacing with vertical panels uses 2-span sheathing bending analysis.
g) Hold-down Design Table
i. Order of Hold-downs (Bug 2116)
Hold-downs were not always listed in order as they occur from west to east or south to north. This has been corrected.
ii. Wind Direction in Legend
The word wind has been removed from wind direction in the table, as it was appearing for seismic design as well as wind.
h) Drag Strut Table
i. Order of Drag Struts (Bug 2116)
Drag struts were not always listed in order as they occur from west to east or south to north. This has been corrected.
i) Deflection Table
i. Legend O86 Reference
The word O86 has been placed before the first design code reference from the CSA O86.
j) Hold-down Displacement Table
i. Rounding of Elongation Values (QA Item 29a)
The hold-down elongation values and possibly other values in the table were not always being rounded to the nearest 1/10 of a millimeter, but rounded to the 1/10 value in the other direction. This has been corrected.
4. Bug Fixes and Small Improvements
a) Tolerance in Equalizing Deflections (Change 227)
b) Nail Withdrawal Force for C&C Design (QA
Item 101a)
The C&C load
for nail withdrawal design was the highest of all storeys on a shearline rather
than the load on the level of the wall being designed. This has been corrected.
c) Selection of Nail Diameter for Interior Wall
Surface (Bug 3218)
In wall input
view, the program did not allow input of nail diameter for the interior side of
a wall. For power driven nails with multiple possible diameters, this meant
that the program selected a diameter at random for design. For all other nails,
selection of nail length uniquely determines the diameter so there was no
problem.
It is now
possible to select nail diameters for both sides of the wall.
g) 1.2 Drag Strut Factor (Change 250)
The 1.2 drag
strut factor from CSA O86 11.8.6 was being applied regardless of the value of IEFaSa
(0.2) when according to 11.8.1 Drag
struts = 1.2 (11.8.6) in the Elevation view legend always appeared
regardless of whether this factor was applied. It now only appears for high
seismic zones when the 1.2 factor also appears for the “S” component of
hold-down forces.
h) Shear Stiffness Bv for Unknown Sheathing Thickness (Bug
3269)*
When determining
the shear-through-thickness Bv from O86 tables 9.3A – C used in the
shear term of the deflection equation in 11.7.2, when the sheathing thickness
had been left unknown, the program was using the Bv for the thickest
sheathing option, or 23/32”, rather than the thickness for the sheathing being
designed. This caused a non-conservative error in the shear term of the
deflection equation of about 5%. The shear term is usually a small component of
the overall deflection.
d) Dead Load Contribution to Hold-down Forces for
Rigid-Only Design (Bug 3153)
Hold-down forces components due to dead loads were not created when designing for rigid diaphragm forces only, that is, when flexible diaphragm analysis is turned off in the Structure view. These force components did not appear in the Hold-down Design table or in Elevation View, and the deflection analysis and design of hold-downs did not include the counteracting effect of dead loads. This has been corrected.
e) Wall Groups for Unknown Power-Driven Nails (QA
Item 88)
When power driven
nails are selected with unknown as
the diameter, the program wasn’t determining the worst case of seismic, wind,
rigid and flexible design for the nail diameters so that extra wall groups
corresponding to the nails designed for each of these criteria were generated,
and appeared throughout the design results. This has been corrected.
1. Zoom and View Settings (Feature 216)
You are now able to
zoom Elevation View in and out and to establish view settings similarly to Plan
View.
a) Elevation View Setting Tab
A tab for Elevation
View has been added to the Settings box, with similar inputs to the View tab for Plan view. The setting
previously called View has been
changed to Plan View.
i. View Area
You can establish the confines of your viewing area with the View area inputs or change them using the Zoom buttons in the Elevation View data bar.
ii. Fit Building to Viewing Area and Fit Viewing Area to Window
These settings act similarly to Plan View, allowing you to recapture the full image of the structure after it has been zoomed.
iii. Plan View Snap Increment
Since there is no interactive input in Elevation View, the snap increment entered in the Plan View settings is shown here, and is used as the metric for the Display gridlines input.
iv. Display Gridlines
You can now display gridlines at a different interval from how they are shown in Plan view using this input.
v. Zoom Increment
You can set the percentage by which the image expands or contracts each time the Zoom in and Zoom out buttons in the Elevation View data bar are pressed.
b) Toolbar Buttons.
Zoom in and Zoom out buttons in the Elevation View data bar expand or contract the image by a percentage increment entered in the Elevation View settings.
c) Mouse Wheel
It is also possible to zoom the image via the mouse wheel, owing to the new feature described in I: 1 below.
2. Multi-storey Selected Walls (Feature 230)
You can now choose to
view Selected Walls while viewing
multiple levels or multiple levels while in Selected
Walls mode. In this case, the
program shows only walls that are above and below the selected walls. This
allows you to view see the entire vertical load path for a single stack of
walls. Previously, it was difficult to do so for long shearlines because the
data tended to overlap.
a) Data Bar Controls
Previously, when Selected Walls was chosen in Elevation view, the levels control was disabled. Now it is enabled.
b) Drawing
When in Selected Walls mode while more than one level is being viewed, the program uses the walls on the level selected in Plan view to determine what walls are shown on other levels. It shows all walls on other levels that are entirely within the extents of the selected walls.
If contiguous selected walls are selected, the program shows walls on other levels within the total extent of the contiguous walls, even if they do not lie within the extent of any one of the selected walls. However, if there is a gap between selected walls, the program does not show walls on other levels that lie even partially within that gap.
If you find this difficult to envision, just experiment with the program.
3. Shading of Non-shear-resisting Segments
(Feature 56)
The following
elements are now shaded in light gray to indicate that they are not considered
shear resisting elements.
a) Shearwall segments
Within shearwalls, segments which are too narrow to be considered full-height segments, and are this not included in design and do not draw force, are shaded.
Openings are shaded above and below the opening.
b) Non-shearwalls
Non-shearwalls are shaded except for the openings.
4. Dimension Lines (Feature 79)
Dimension lines
indicating the length of full-height segments or of perforated walls, opening
length and height, joist depth and wall height are now shown in Elevation View.
In both the Show menu for Elevation View, and in the Display data group of the Options settings there is a checkbox to turn off the display of dimensions for walls and for openings independently. Joist thickness is also turned off when walls are turned off.
b) Location of Dimension Lines
i. Full Height Segments and Perforated Walls.
Full height segments in all shear walls and entire non-shearwalls are dimensioned in the bottom area of the wall.
ii. Openings
The horizontal dimension of openings is shown on top of the opening if there is room, otherwise within the opening.
The vertical dimension of openings is shown inside the opening on the right-hand side.
iii. Wall Height and Joist Thickness
The wall height is dimensioned to the left of the entire shearline, and the joist thickness to the right.
c) Format
Dimensions are in feet or meters, and you can control whether feet-inch or fractional feet, and whether fractional inches are shown, using the Imperial Format setting for Distance.
5. Display of Roof Line and Gable End (Feature
228)
In
the Show menu while in Elevation view
and the Display data group of the
Options Settings in the Elevation view column, items have been added for the
display Gable end and for Roof.
When Roof is checked, the gable end is always shown, and its checkbox is disabled and checked.
i. Gable End
This setting controls the display of the triangular gable end of the wall. If the setting Ceiling acts as upper level diaphragm is checked in Structure view, this portion of the wall is not considered part of the shear wall, and turning off the setting economises on space without compromising the depiction of forces on the line.
ii. Roof
This setting controls the display of side panels and hip ends, which do not affect the distribution of forces within the shearline, so this setting can be turned off to economize on space if only the forces within shear walls are of interest.
b) Gable Ends
Gable ends are part of the end wall, and it was previously unclear whether they were considered part of the shear wall, as they are if Ceiling acts as upper level diaphragm is unchecked in Structure view.
i. Wall drawing
If selected for display, gable ends are drawn in the same green colour as the wall.
ii. Force arrows
When Ceiling acts as upper level diaphragm is unchecked in Structure view the program draws the arrows for the diaphragm shear force and the segment shear forces along the slope of the gable end rather than at the level of the top of the upper storey.
These force locations are used in the calculation of the moment arm for hold-down force calculations, however previously that was not apparent.
If you choose not to draw gable ends, then the forces are drawn along the top of the upper-level wall at eave height, even though they act at the height of the sloping roof.
c) Hip Roof and Side Panels
Hip roof panels and side panels are drawn in a mid-gray colour, and the entire outline of the panel is drawn, including the line at eave height.
The panels are drawn only if the roof block edge is collinear with the wall, in other words, if the roof is made of rafters, the wall supports the rafters.
Roof panels are drawn only for those blocks whose highest level corresponds to one of the levels selected in Elevation view.
6. Segment Numbers (Feature 77)
a) Display Setting
In the Show menu and in the Display data group of the Options settings, you can now turn on and off the display of segment numbers. By default, they are off.
b) Segment Number
In the upper portion of shear wall segment, centered horizontally, the program shows the segment number after the wall number, e.g. A-1,1; A-1, 2; etc.
c) Critical Segment
Within the design results text below the drawing, the program now gives the critical segment, e.g. A-4,2, in which 4 is the wall number and 2 is the segment number. Previously it just indicated the segment was within wall A-4.
7. Bug Fixes and Small Improvements
a) Placement of Segment Shear Force Values (Feature 79)
For multi-storey structures, the numeric value of the shear force on each segment has been raised above the arrows for the design shear force on the storey above, if they would otherwise be obscured by them or by the diaphragm itself.
b) Crash for Offset walls with Dead Loads (Bug 3138)
For shear walls offset from the shearline location, and if dead loads were on the wall, the program was crashing when Elevation View was viewed. This has been corrected.
i)
Selected Walls
from Multiple Shearlines (Bug 3167)
When individual walls from different shearlines were selected in Plan view, Elevation view in the Selected Wall mode showed all these walls, even if they overlap. Now the program shows only the walls from the first shearline selected, as it does when multiple entire shearlines are selected when in Entire Shearline mode.
j)
Disabled Level
Input in Elevation View (Bug 3172)
After re-entering the Structure action or Roof action in Plan View are selected, then going to Elevation View, the Level input was disabled, and you were unable to change the levels being viewed. This has been corrected.
k)
Drawing of Offset
Walls (Bug 3175)
When walls on a shearline are offset in plan from neighbouring walls, in Elevation view the offset walls were drawn slightly than normal, causing a small gap between walls. This occurred consistently when viewing one level and occasionally when viewing multiple levels, and has been corrected.
l)
Rescaling after
Disabling Material Information (Bug 3177)
After disabling the framing, nailing, or sheathing information under the shear walls in Elevation view, it did not rescale to accommodate the change in information. This resulted in you being unable to see the information when it was re-enabled, or the view having a large amount of blank space along the bottom when the information was disabled. These problems have been corrected.
m)
Vertical Elements
(Change 223)
It is now possible to turn on and off
vertical elements via the Show menu in Elevation view.
The program now zooms
the drawings of the structure via the mouse wheel. Previously this could only
be done via toolbar buttons.
In Plan View and for
the new zoom feature for Elevation view, when the Control key is depressed,
each click on the mouse wheel expands or contracts the image by percentage
increment given in the View settings, like one push on the zoom button.
2. Wall Depiction in Plan View (Feature 56)
a) Non-full-height Segments
All shearlines with aspect ratios that are too narrow for design given the selected Design Settings are now shown with a white interior and coloured border the same as a non-shearwall, as they are effectively non-shearwall segments.
b) Legend
A legend below at the bottom of the screen shows the markings for Shearwalls and Non-shearwalls.
3. Design Case in Plan View (Feature 83)
The program now
indicates explicitly Plan View
whether you are viewing seismic or
wind loads, which wind load method, and the force distribution method (rigid or
flexible diaphragm). Previously you had to infer this information from the
arrow style, existence of large low-rise arrows, and other clues.
a) Loads and Forces View
In the line in the legend previously starting with Loads shown W or Loads Shown E it now shows,
Loads: Low building Wind
(W); Forces 1.4W + 0.9D; Flexible distribution
Loads: Any building Wind
(W); Forces 1.4W + 0.9D; Flexible distribution
Loads: Seismic (E); Forces
1.0E + 1.0D; Flexible distribution
b) Loads Generate View
Where it previously said Unfactored generated shear load, the program now says, for NBC 2015
Unfactored generated wind load using NBC
4.1.7.6 for low buildings (plf)
Unfactored generated wind load using NBC
4.1.7.5 for any building (plf)
Unfactored
generated seismic load (plf)
For NBC 2010 it is
Unfactored
generated wind load using NBC Fig. I-15 for any building (plf)
Unfactored
generated wind load using NBC Fig. I-7 for low buildings (plf)
4. Bug Fixes and Small Improvements
a) Gap in Building Footprint for Openings Extending to Wall End (Bug 3142)
Following a specific sequence of wall input steps, it was possible to create a gap in the exterior footprint, rendering the project file unusable.
This occurred when an opening was than extends to the very end of a wall, meeting a perpendicular wall. If the location of the wall with the opening is then moved, followed by moving the wall it meets, the gap is created.
This problem has been corrected.
b) Zoom Buttons in Fit Building to
View Area Mode (Bug 3170)
In Plan View, when Fit Building to Viewing Area is active, the zoom buttons on the toolbar were disabled, because the building no longer fits the viewing area when zoomed.
However, this view option is the default, so it was often unclear why the zoom buttons were disabled. For this reason, the zoom buttons now remain enabled, and their use deactivates the Fit Building to Viewing Area setting.
This behaviour is also adopted for the new feature of zooming and Fit Building… for Elevation view.
1. Separate Torsional Analysis and Load Generation
Output
The output report showing intermediate
calculations for load generation and for torsional analysis has been split into
two separate files, one for load generation and the other for torsional
analysis.
a) Toolbar buttons
The toolbar button that previously showed the word log and is called Load Generation and Torsional Analysis Details has been replaced by two buttons, one which shows three arrows and is called Load Generation Details, and another which shows a semi-circular arrow and is called Torsional Analysis Details. These buttons are adjacent to the existing button for Detailed Shearwall Design.
The button for the primary design results has been changed to convey the tabular nature of that output.
b) Operation
Previously, the combined file was output
when loads were generated, then appended to after Design button was pressed
when the torsional analysis is performed. If loads were then regenerated, the
torsional analysis results were lost. Other synchronization problems
occasionally occurred.
Now, the Load Generation Details file is output when loads are generated and
Torsional Analysis Details when the design is performed, eliminating any
interference between the two.
c) Headers
The titles and headers to the load
generation and torsional analysis results have been redesigned to achieve a
consistent format across all three intermediate output files, torsional
analysis, load generation, and shear wall design.
d) Getting Started Steps
The 14th and final step in the
introductory Getting Started window
has been modified to refer the Torsional
Analysis Details, Load Generation
Details, and Detailed Shearwall
Design output reports rather than the log file.
a) Hold-down Setting Input Field Sizes (Change 244)
Sime of the
inputs in Wood Properties and
Construction Details section of the Hold-down
settings were too small to show typical data without scrolling, and have been
enlarged.
b) Activation of Imperial Formatting on Change of
Unit System (Change 246)
In the format
Settings when changing from Metric to
Imperial units, the Imperial Formatting input remained
disabled. It is now active immediately upon changing to Imperial.
n) Format Settings Typo (Change 221)
In the list of Imperial format choices in the Format settings, the examples were prefaced by "e.g." rather than "e.g.", the correct spelling. This has been corrected.
c) Display Settings Names (Change 231)
The word “table” has been removed from several Options Settings in the Display design results group, as it had been inconsistently applied to some design results tables and not others. The setting that previously said Materials table now says Sheathing/framing materials; in all other cases the word “table” has just been excised.
d) Reset Original Settings for Cities in Default
Settings (QA Item 84a)
After clicking the Reset original settings button in the Default Values settings page, the default province was correctly set to British Columbia, but the list of cities showed those in Ontario instead of British Columbia, with the default being Kincardine rather than Vancouver (City Hall). If you then then select a city from the list the wrong velocity pressures were selected.
These problems have been corrected.
e) View Setting Nomenclature
The following changes have been made to the data field labels in the View settings, which area now shown in separate Plan View and Elevation View boxes:
i. Mouse Click Interval (Change 225)
The word intervals has
been changed to snap increments for
consistency with the nomenclature in Display
Gridlines, which uses the term snap
increment. For Display gridlines, Snap has been changed to snap.
ii. Save to Project File (Change 226)
An asterisk (*) has been placed beside those inputs that are not saved to the project file, with an explanatory note at the bottom of the box. These inputs are the zoom increment and the Fit Building… and Fit Window… settings.
3. Bug Fixes and Small Improvements
a) Crash on Input of Standard Walls (Bug 3202)
After restoring all Standard Walls to the ones that originally came with the program using the Default Values setting, the program crashed if there were any standard walls that you had made being used in the project.
Shearwalls now only allows the standard walls to be reset if there are no open documents. If you attempt to reset them with a document open, the program now prompts you to close the open document.
b) Levels Indicator for One-storey Structure
(Change 249)
For a one-storey
structure, the Levels indicator is
shown in the Extend to field. Now it
is shown in the Current level and the
Extend to field is invisible in this
case.
c) Error Message for Ceiling Depth (QA Item 14)
Upon inputting
the ceiling depth above level 6 in Structure input view, a Windows “improper
argument” message appeared. This has been corrected.
d) Spelling of C&C (Change 222)
Changed all instances of C & C to C&C in the Show menus, Load Input view, drawings, and output. Also changed End Zone to End zone and Load to load.
e) Show Menu Groups (Change 224)
Added a separator to the Elevation View Show menu separating the options dealing with graphical elements such as wall names with those dealing with design results text.
f) Wall Segment Nomenclature (Change 243)
The title of the
section of wall input view giving the hold-down configuration, location, now
says e.g., Wall A-1 rather than Wall segment A-1. The inputs are for an entire
wall, including openings and possibly several segments, not for an individual
shear wall segment.
Shearwalls 9.3.2
– December 8, 2015 – Design Office 9, Service Release 3a
Note that this
service release also includes the change listed for version 9.3.1, which was a
hot-fix version distributed only to the user who reported the problem.
1. Boundary Element Stud Sizes (Bug 3111)
The following
problems with the boundary element stud sizes occurred when imperial units were
selected, appeared in the Framing Materials table of the design summary output
and affected the calculation of A in the equation for deflection from O86
11.7.1.2.
They also created
problems in terms of identifying walls with similar attributes, so that
duplicate standard walls and wall design groups were created. These problems
have been corrected.
a) Nominal vs. Actual Units for Stud Sizes
If a non-standard (custom) stud width or depth was entered, then a standard width or depth reselected, the program was using the nominal value of the standard width or depth (e.g. 6.0”) when it should have been using the actual width (e.g. 5.5”).
b) Custom Stud Sizes
After saving a project with non-standard (custom) stud widths or depths, upon reloading the file the size of the width or depth was the value of the width or depth in mm. rather than inches.
2. Hold-down Force Increase for High Seismic Force
(Bug 3116)
The program was
implementing O86 11.8.2, the increase in hold-down design force by 20% for high
seismic zones, only if Shearwall capacity
is selected for Hold-down force based
on... in the Design settings. It is
now implemented regardless of whether this setting is selected.
3. Perpendicular Direction Load Distribution from
Manual Area Building Masses (Bug 3099)
Starting with version
8.1, manually input area building masses were creating a point seismic load in
the direction defined by the start and end of the building mass, as well as the
line seismic load in the perpendicular direction representing the distributed
area mass in that direction.
The point load does
not correspond to the actual distribution of mass and has been removed. In its
place, there is a line load representing an area mass originating at the
location of the building mass, and extending the tributary width that was input
for the building mass. The tributary width used to create this load is the
length of the input mass.
4. Absence of Failing Walls in the Design Summary
(Bug 3112)
If at any point in
designing a shear wall, the program rejected a possible wall because it did not
meet the ductility criterion, then if the wall finally selected failed because
of insufficient shear wall capacity, it did not appear in the Design Summary
page listing all failed shear walls.
The ductility
criterion, from O86 11.8.1, is that in order to ensure ductility, the critical
failure mode for the wall is mode d, e, or g from O86 12.9.4.2.
Shearwalls 9.3.1
– December 2, 2015 – Hot Fix
1. Seismic Mass from Interior Non-Shearwall
Shearlines (Bug 3094)
The building masses
created from interior shearlines composed entirely of non-shearwalls were not
used to create seismic loads, nor was the mass included in the calculation of
total mass of the structure for base shear calculations. This has been corrected.
Shearwalls 9.3 –
September 11, 2015 – Design Office 9, Service Release 3
This service release
provides design for CSA O86-14 standard, as well as allowing continued use of
CSA O86-09. The following is an index of
links to changes described in more detail below.
2. Design Code Clause References
9. Nail Slip for Deflection en
10. Gypsum Wallboard (GWB) Design
11. Service Condition Factor KSF
1. Unit Nail Resistance Nu for Anchorage
Deflections
2. Shearwall Capacity Hold-down Method in the Calculation of
Deflections (Bug 2999)
3. Non-standard Nail Diameters (Bug 2664)
4. Wind Load Storey Drift Table (Bug 3032)
5. Standard Walls and Design Groups
6. Special Seismic Checks in Design Summary (Change 220)
7. Message Box for Gypsum Wallboard Rd Factor
8. Percent Resisted by Gypsum Table
9. "Improper Argument" error for OSB Sheathing (Bug
3012)
10. Elevation View Failure Message for Passing Walls (Bug
3007)
11. Both Direction Output in Storey Drift Table (Bug 3018)
12. Moisture Conditions Label (Change 217)
13. Moisture Conditions Description in Input and Output
(Change 218)
14. Extra Null Lines in C&C Design Table (Bug 3035)
15. Plan View Legend Wording for Failed Walls (Change 177)
1. Duplicate and Missing Low Rise Wind Loads (Bug 3002)
2. Centre of Mass and Center of Rigidity in Plan View
(Feature 218)
3. C&C Wind Loads in Both Directions (Change 176)
4. Crash Upon Input of C&C Load (Bug 176)
5. Update of Add Load Dialog Input (Bugs 3005, 3077)
6. Missing Elevation View Forces in for No Deflection
Analysis (Bug 3003)
7. Missing Snow Load Note in Load Generation Dialog (Bug
2988)
8. Nonsensical Torsional Forces in Log file for Low Rise Wind
Design (Bug 3006)
9. Multi-block Low Rise Height to Width Setting (Change 183)
11. Load Generation Details Results in Log File
1. OSB and GWB in Wet Service Conditions (Bug 3000)
2. Plywood Sheathing Plies (Bug 2994)
3. Custom Plywood Thickness (Bug 2994)
4. Nail Penetration Imperial Unit Format (Change 180)
5. Nail Diameter Format (Change 219)
6. MSR Grade Design Note (Change 215)
7. OSB Panel Marking Design Note (Change 216)
1. Extend Upwards Operation (Bug 3073)
2. Settings Dialog for Medium and Large Display Size (Bug
3068)
3. “Getting Started” Steps Display (Change 181)
5. WoodWorks Sales and Technical Support Contact Information
(DO Change 6)
6. Parentheses in the Help
About box (DO Change 7)
7. Apply Button in Settings Dialog (Change 185)
8. Update of Roof Overhang Input (Change 186)
9. Image File Wording in Message (Change 182)
10. Typo in Out-of-date Design Message Box (Change 178)
The program now
implements the new CSA O86-14 Engineering Design in Wood Standard. As the
National Building Code referencing CSA O86-14 is not yet released, and
provincial building codes have not yet mandated the use of O86-14, the program
also allows you to continue using CSA O86-09.
Input
a) Design Code Selector
A drop list box called Design Code has been added to the Design settings in the Design procedures data group, with the choices
CSA O86-09/ NBC 2010
CSA O86-14/ NBC 2010
b) Output
The Design Settings output has been changed from showing only the National Building Code edition to showing CSA O86-09 / NBC 2010 or CSA O86-14 / NBC 2010.
c) Program Information
It shows the edition of the O86 currently being used, and the fact that it is the May 2014 printing of the CSA O86-14, in the About Sizer box accessed from the Help menu and in the Building Codes box accessed from Welcome Box. In the main body of the Welcome box, it indicates that either of these codes can be used.
2. Design Code Clause References
a) Update to 2014
The references to the CSA 086 design code clause numbers in the input forms and screen messages, and in warnings, design notes and other program output, have been updated to show the 2014 edition clause numbers when CSA O86-14/ NBC 2010 is chosen as the design setting. It continues to show 2009 edition numbers when CSA O86-09/ NBC 2010 is chosen.
b) On-line Help
The on-line Help has been updated to refer to the CSA O86-14 design code clauses. The unrevised online Help is also included in the installation to allow you to use Help that references O86-09.
The Design Office installation
the on-line 2014 edition of CSA O86 in .pdf form has been made available. program
now allows you to view either the CSA O86-14 or CSA O86-09 design code, and
both documents are included in the Design Office installation.
The Welcome box now
indicates that both design codes are available. The Help About Shearwalls box and the Building Codes box show information about the currently selected
design code.
a) 5- and 6 Storey Provisions
The Building Codes box and the message that appears when you enter more than 4 storeys have been updated to refer to the 5- and 6- storey provisions in the NBC 2015 rather than the BC Building code. Information about continuous hold-down systems and rotational deflection required for taller structures has been added to the Building Codes box
b) Wood Shrinkage and Irregularities
Information about
wood shrinkage and irregularities not considered has been removed from the
Building Codes box.
In all messages,
notes, warnings, and output tables, the program shows design code clause
numbers for either O86-14 or O86-09, according to which is selected.
The rest of the changes described
in this section occur when CSA O86-14
is selected as the design code edition in the Design Settings, unless
otherwise indicated.
For wood-based
structural panels, the program now calculates Vrs via the
expressions in O86 11.5.1:
φ vd JD ns Jus Js Jhd Ls (lateral
nail resistance)
φ
vpb KDKSKT Ls (panel buckling)
The worst case of
these two equations is determined for each side of the sheathing, and then the
two sides are summed.
Previously only the
expression
Φ vd KDKSF Jub Jsp Jhd Lw
was used.
The following
subsections apply to wood-based panels only; the procedure for gypsum wall
board has not changed.
The calculation of Vhd, which is just Vrs without the Jhd factor, for use in determining the Jhd factor, considers both the lateral nail resistance and the panel buckling equations, despite the fact that Jhd appears only in the nail resistance equation. (This was decided upon after consultation with the design standard authorities.) The procedure for combining sides is thus:
- determine worst case Vhd (nailing) vs. Vrs (panel buckling) on each side
- combine the sides to calculate Jhd
- take Vrs nailing = Vhd * Jhd on each side
- take worst case Vrs (nailing) vs. Vrs (panel buckling) on each side
-
combine the sides again
The resistance factor φ has increased from 0.7 to 0.8, the value that has always been used for nail resistance, for both panel buckling and nailing equations.
c) Vrs due to Nailing Strength
Vrs from O86 11.5.1(b) is calculated as follows:
Unit lateral Vd is now calculated via the equation Nu/s, where Nu is the factored unit lateral nail strength in N from O86 12.9.4.1 and s is the edge nail spacing, rather than tabulated values based on sheathing thickness and nail sizes.
The notes to O86 09 9.4.4 representing strength adjustments for special cases are no longer applied.
ii. Impact on Nail Selection
Nu varies continuously according to nail length, diameter, and penetration depth, whereas Table 9.4.4 provided only a very limited number of choices, conservatively specifying a minimum nail diameter for which the tabulated values were valid, and a required penetration depth.
This means that the choice of nail size has a much bigger impact than before; the program has added more nail sizes and types to the program as described in J: 8 below.
iii. Nu Factors
Nu from 12.9.4.1 is given by nu KSF KD KT, with the K factors implemented as follows.
The service condition factor KSF comes from O8612.2.1.5 for connections. The same service factor is applied to all walls in the structure based on the in-service and fabrication conditions input in the Design Settings. Green fabrication or wet service conditions correspond to moisture greater than 19%.
For changes in the service factor input, terminology and calculations, refer to J: 13 below.
This is set to 1.15 for both wind and seismic. It does not represent a change from the previous version.
3. Treatment Factor KT
As the factor for studs is one unless they are incised there is no program input of treatment factor and KT = 1, always.
nu is calculated by the yield mode equations in 12.9.4.2. The following inputs correspond to a single shear plane plywood-to-stud connection:
1. Side member thickness t1
This is the sheathing thickness in mm.
2. Nail diameter d
As input in Wall Input view.
3. Stud embedment strengths f2, f3
Determined from density of stud and nail diameter.
Nail length minus the sheathing thickness. The ability to include gypsum wallboard underlay in the sheathing thickness has been added because of its effect on nail penetration – see J: 9 below for details.
5. Nail yield strength fy
Determined from nail diameter.
6. Structural panel embedment strength
Determined from density of sheathing material (CSP, DFP, or OSB), and nail diameter.
According to 11.8.1, to ensure ductility, the wall should fail in modes d, e, or g from 12.9.4.2.
For each wall design or candidate design for unknown parameters, the program will record whether the lowest value of the nail failure modes for either side of the shear wall is not d, e or g.
If a completely
specified wall, or for a failed wall arrived at when all unknown possibilities
are exhausted, fails because of the ductility check, the symbol # appears beside the wall capacity in the shear results table and a note
below the table indicates a design failure and the reason.
The program passes
over candidate designs for which the ductility check fails. If the program
cannot find a design, and at least one wall that had sufficient capacity was
rejected because of nail ductility, the symbol @ appears by the wall capacity and a message below the table informs you
what happened.
vi. JD Factor for Diaphragm and Shear Wall Construction
This factor is always set to 1.3.
vii. Number of Shear Planes nS
As mid-panel shear walls are not to be included in this version, the value of ns is always 1.
viii. Unblocked Factor Jus
The nomenclature for this factor has changed, but in terms of engineering design there have been no changes to program.
This factor is implemented according to O86 11.4.1, a formula based on panel edge spacing. It is less than one for spacing less than 150 mm, and equal to one for larger spacing.
d) Vrs due to Panel Buckling Strength
Vrs from
O86 11.5.1(c) is calculated as follows:
i. vpb Calculation
The following parameters are used in the equation for specified panel buckling strength vpb:
1. Axial Stiffness Ba,90, Ba,0
The axial stiffness values Ba,90, Ba,0 from tables 9.3A ,9.3B and 9.3C for each plywood or OSB thickness, and no. of plies for plywood and panel marking for OSB, have been added to the program. The value Bv was already in the program for use in deflection analysis.
For both Ba and Bv, if you enter a larger sheathing thickness value than is in the dropdown list, but one in table 9.3A-C , the correct value for that size from 9.3A-C is used. Previously, for Bv the program used the value from the largest thickness in the dropdown list. If you type in a larger thickness than is in the table, the input is rejected with a warning.
As the buckling resistance gets larger as the smallest dimension of the sheet used gets smaller (because of the “b” in the denominator of the vpb equation the critical panel), the critical panel within a segment is the largest one. Therefore, full 4 x 8 sheets are used for those segments that are larger than 4 feet wide for vertical sheathing and 8 feet for horizontal orientation. For smaller segments, the size of the largest component panel is determined, for example a 6-foot segment uses 4’ x 6’ for horizontal sheathing and 4’ x 8’ for vertical. A segment 3 feet wide uses 3 x 8 for vertical and 3 x 4 for horizontal.
ii. Service Condition Factor KS
For wet service conditions as input in the design settings, the program uses KS from Table 9.4.2 and applies factor of 0.80. Wet fabrication conditions to not apply to plywood.
Note that wet service conditions are no longer allowed for OSB or gypsum wallboard, see M: 1 below.
iii. Treatment Factor KT
Due to the rarity of use of treatment factors for plywood and OSB, the program does not include an input for treatment and this factor is always 1.0.
iv. Duration Factor KD
This is set to 1.15 for both wind and seismic.
e) Design Results Output Tables
i. Shear Design Table
In the Shear Design table, the total force on the wall or segment Fv and the corresponding capacity Vr have been removed from the table to make room, and because they are not particularly useful to the designer.
Where the table previously had one unit capacity Vhd/L, it
now shows unit capacities for nail resistance and panel buckling separately,
headed by Vhd (vd) / L and Vrs (vpb) / L, respectively. The table
shows values for interior and exterior sheathing sides for each. The combined Vrs/L is still shown.
Corresponding
changes have been made to the explanatory legend below.
ii. Framing Materials Table
The Jsp column and legend entry have been removed from the Framing Materials table, as it no longer applies for O86-14.
iii. Sheathing Materials Table
In the Sheathing Materials table, the Jub heading and legend description have changed to Jus.
f) Design Notes
Design notes appear below the Sheathing Materials table that indicate sheathing and nailing requirements, and adjustments to strength for particular configurations. The following changes have been made to these notes:
i. Blocking Requirements
Added design code references 11.4.4 and 9.4.4 for 086-14 and O86-09, respectively. Added sentence saying unblocked panels must be staggered.
ii. Nailing Requirements
Added design code references 11.5.3.4and 9.5.3.4 for 086-14 and O86-09, respectively. Cleaned up character spacing issues.
iii. Framing and Panel Requirements
Added design code references 11.5.3.2 and 9.5.3.2 for 086-14 and O86-09, respectively. Changed “wide” to “thick” to make stud dimension clearer. Show metric or imperial thicknesses according to units selected. Cleaned up character spacing issues.
iv. Shear Strength Upgrade for Stud Spacing 400 mm or Less
This is Note 1 or Note 2 in Shearwalls, and is from the asterisk (*) under O86-09 Table 9.5.1A. This note has been removed for the O86-14. Minor formatting improvements for 09.
v. Double Studs at Panel Edges for 50 mm Edge Nailing
In Shearwalls, this is Note 3 for O86-09 and Note 1 for O86-14, and is from the symbol Ɨ under O86-09 Table 9.5.1A. Show metric or imperial thicknesses and nail spacing according to units selected. For imperial, say “minimum 3-by or double 2-by”. Add 11.5.3.5 a reference for O86-14. Minor formatting improvements.
vi. Double Studs at Panel Edges for 75 mm Edge Nailing and 3.66 mm Nails
In Shearwalls, this is Note 4 for O86-09 and Note 2 for O86-14, and is from the symbol ǂ under O86-09 Table 9.5.1A. Shows metric or imperial thicknesses and nail spacing according to units selected. For imperial, say “minimum 3-by or double 2-by”. Added 11.5.3.5 b reference for O86-14. Minor formatting improvements.
vii. Staggered Panel Edges on Opposite Sides
In Shearwalls, this is Note 5 for O86-09 and Note 3 for O86-14 is Note (3) under O86-09 Table 9.5.1A. Add 11.5.3.5 reference for O86-14. Minor formatting improvements were also made.
viii. Jn Factor for Non-Standard Nails
In Shearwalls, this is Note 6 for O86-09, and has been eliminated for O86-14, as there is no Jn factor.
ix. MSR Grade
In Shearwalls, this is Note 7 for O86-09, and has been eliminated for both design codes. Refer to M: 6 below for more details.
x. OSB Panel Marking
In Shearwalls, this is Note 8 for O86-09 and Note 4 for O86-14. Add design code references 11.5.3.3 and Table 9.5.1A Note 6 for 086-14 and O86-09, respectively. Fixed problem with panel marking output, refer to M: 7 below, (Change 216).
g) Detailed Design Results
Upon design, the program outputs a new file containing intermediate design data, called [projectname].swd. A menu item and toolbar button each called Detailed Shearwall Design access this file and show it in a reader similar to the one showing the Load Generation and Torsional Analysis log file.
i. Symbols
The output starts with a table showing all the symbols used in the equations governing shearwall design and shown in the headers for the tables in this file. Each line shows the symbol, definition, two columns for units employed, and the reference to the O86-14 clause where the symbol is defined or used.
The first unit is for those that appear in the equations as published in the O86, and the second one is for the units that are shown in the tables below. For imperial units, the first set will be metric and the second set imperial. For metric units, the columns usually show the same units, except for cases that the table shows for example kN rather than N for formatting convenience.
ii. Equations
The symbols are followed by a section showing the equations employed, along with the design code clause reference for each one.
iii. Constant Data
There are two lines of data that are the same for all shear walls. The first line shows data that can’t be changed by the user, the second shows ones that can, or may be in future versions of the software. These lines contain the safety factor φ, diaphragm factor JD, duration factor KD, service factors KS, treatment factors KTp and KTn , and number of shear planes ns.
iv. Data for Entire Shear Wall.
For each shear wall, there is a line for data that are independent of the wall segment or sheathing side, showing wall height and total shear force Vr in each direction on the wall.
v. Panel Buckling Vrs
For each shearwall, there is a table showing the data
needed for panel buckling Vrs calculations from O86 11.5.1(c). There
is a separate line for each shearwall segment between openings and for the
interior and exterior sheathing sides. The data shown are segment length, sheathing
thickness, shear force per unit length, unit panel buckling strength vpb, panel
buckling factor Kpb, critical panel dimensions a and b, panel axial
strengths Ba0 and Ba90, shear through thickness rigidity
Bv, and parameters η (eta)
and α (alpha).
vi. Nailing Vrs
For each shearwall, there is a table showing the data needed for nailing Vrs calculations from 11.5.1(b). There is a separate line for interior and exterior surface. The data shown are nail diameter, panel thickness, nail penetration length, shear strength Vhd per unit length, unit shear strength vd, fastener spacing factor JS, unblocked factor JUs, nail spacing, factored nail strength Nu, yield modes a,b, d, e, f and g for unfactored nail strength nu. marking the critical mode with an asterisk (*) and indicating whether it is ductile or non-ductile.
For each shearwall, there is a table showing the data needed for hold-down factor Jhd and the determination of final shear strength Vrs. For each wall segment, the program shows the Vhd on each surface derived from the critical panel buckling or nailing Vrs; the combined Vhd, then for each force direction it shows the uplift force Pij used for Jhd, hold-down factor, Jhd, and the resulting combined worst-case Vrs on each surface of the wall.
As the calculation of
shear strength Vrs now depends on the exact nail diameter and nail
penetration length, and given the prevalence of power-driven nails, the program
has greatly expanded the selection of nails available in Shearwalls. Unless otherwise indicated, these changes
apply regardless of whether O86-09 or O86-14 is selected as the design code.
a) Fastener Types
Previously the nail types available for structural sheathing were Common wire nails and Non-standard nails. The program now allows the following choices
Common wire nails
Spiral nails
Ring nails
Power-driven nails
Power-driven nails correspond to the previous Non-standard nails, with changes to functionality described below.
b) Manually driven Nails
i. Lengths and
Diameters
The following table shows the correspondence between diameter and length for each fastener type now available in Shearwalls:
|
Length (in) |
Length (mm) |
Common wire nails |
Spiral nails |
Ring nails |
|||
|
|
|
in |
mm |
in |
mm |
Nom in |
Nom mm |
|
1-3/4 |
44 |
- |
|
- |
|
0.109 |
2.769 |
|
2 |
51 |
0.113 |
2.87 |
0.120 |
3.048 |
0.120 |
3.048 |
|
2 |
51 |
- |
- |
- |
- |
0.134 |
3.404 |
|
2-1/4 |
57 |
0.113 |
2.87 |
- |
- |
- |
- |
|
2-1/2 |
64 |
0.131 |
3.33 |
0.120 |
3.061 |
0.134 |
3.404 |
|
3 |
76 |
0,148 |
3.76 |
0.135 |
3.429 |
0.148 |
3.76 |
|
3-1/4 |
83 |
0,148 |
3.76 |
0.135 |
3.429 |
- |
|
ii. Dependence on Sheathing Size
For CSA O86-14 design, the program no longer limits the fasteners used based on sheathing size. All nail sizes are allowed for all sheathing thicknesses. For CSA O86-14, only nails that meet the min. penetration in Table 9.5.1A are allowed.
iii. Ring Nail
Design Diameter
For ring nails, the value shown for diameter is the size of the wire the nails are made from. The nominal values are shown in the user interface, but for design, the program subtracts 2 mm = .0075” to arrive at the root diameter to be used for the design equations.
iv. 2” Ring Nail Diameters
In previous versions of the program there is a one-to-one correspondence between nail length and diameter. Now there are now two diameters for 2” ring nails. In this case, if you select ring nails, the program selects by default the first of the diameters, 3.048mm, which you can then change. This diameter is be used for design for unknown nail length when the cycle reaches 2”.
c) Power-driven Nails
i. Lengths and
Diameters
The following table shows the correspondence between diameter and length for power-driven nails available in Shearwalls:
|
Length |
Diameter |
||
|
in |
mm |
in |
mm |
|
1-7/8 |
44 |
0.131 |
3.33 |
|
2 |
51 |
0.113 |
2.87 |
|
2 |
51 |
0.131 |
3.33 |
|
2 |
51 |
0.120 |
3.048 |
|
2-1/8 |
54 |
0.48 |
3.76 |
|
2-1/4 |
57 |
0.92 |
2.33 |
|
2-1/4 |
57 |
0.99 |
2.50 |
|
2-1/4 |
57 |
0.105 |
2.68 |
|
2-1/4 |
57 |
0.113 |
2.87 |
|
2-3/8 |
60 |
0.113 |
2.87 |
|
2-1/2 |
64 |
0.120 |
3.048 |
|
2-1/2 |
64 |
0.131 |
3.33 |
|
2-5/8 |
67 |
0.148 |
3.76 |
|
2-3/4 |
70 |
0.148 |
3.76 |
|
3 |
76 |
0.120 |
3.048 |
|
3 |
76 |
0.131 |
3.33 |
|
3 |
76 |
0,148 |
3.76 |
|
3-1/4 |
83 |
0.148 |
3.76 |
Previously the lengths and diameters available for non-standard nails were the same as those for common wire nails, the difference being that you could enter your own value for non-standard nails.
ii. Unknown Nail Sizes
The program now allows you to specify unknown length for power-driven nails, and the program cycles through the possible lengths to achieve design.
If a known nail length is selected, the program lists the diameters for that known nail length only and selects the first by default, as the program does not cycle through nail diameters.
If unknown is entered as the nail length, then all possible nail diameters are listed. If you select one of these nail diameters the program will continue to show unknown for nail length, and when the design loop runs, it will only design for nails that have that diameter.
If the diameter is unknown and you type in a nail length, the program selects the diameter corresponding to the closest nail in the list to the nail length that was typed in.
iii. Minimum Nail Length
As per NBC Table 9.23.3.5.A, you cannot enter a nail length less than 1.75” – the program will revert to the previous value and issue an explanatory message. Previously there was no lower limit on nail length in Shearwalls.
If a nail is entered between 1.75” and 2” in length, a message appears saying that the nail should be ring-threaded, as per Table 9.23.3.5.A.
iv. Maximum Nail Length
As per the intent of O86 14 (see J: 8.d) below), you cannot enter a nail diameter greater than 3.76 mm – the program reverts to the previous value and issues an explanatory message. Although before O86-14 there was no upper limit, this limit is imposed regardless of whether O86-09 or CSA O86-14 is selected in the Design Settings.
v. Design Routine
When the length and diameter are left as “Unknown”, if when cycling through lengths the program arrives at one that has more than one diameter, it chooses the one corresponding to the common wire nail of that length.
vi. Output
Previously, in the Sheathing Materials table, the size of a non-standard nail was rounded off and converted to the closest fractional size, one which is often the same as a standard nail. Now, power driven nails are output in decimal format to distinguish them from standard nails that are in fractional format.
The program is was using nail diameters listed in the CSA O86, from the CSA B111 standard, however it has been determined that these diameters do not correspond to the wire gauges currently used to manufacture nails, which are from the ASTM F1667 standard. Several limitations are based on the nail diameters, such as O86-14 11.4.5.5 that limits nail diameters when anchorages are used to 3.25 mm, and 11.3.1.1, which says that shearwalls must use nails 3.66 mm or less.
We have changed those limitations 3.33 mm and 3.76 mm, respectively, to correspond to the nail diameters we use in the program for nails of the corresponding lengths.
The messages that appear when these limitations are imposed have been modified to explain this decision. In addition, if a nail between 3.66 and 3.76 is used in design, or a nail between 3.25 and 3.33 when Jhd < 1, a new note appears below the sheathing materials table saying that the nail conforms to the intent of 11.3.1.1 or 11.4.5.5.
The program now
includes the ability to gypsum underlay because it affects nail penetration and
therefore shear strength for O86-14. This feature is also available if O86-09
is selected, and in this case affects whether a nail length achieves minimum
penetration for shear resistances in Table 9.5.1
a) Input
Choices of no
gypsum underlay, ˝”, and 5/8” underlay have been included in
the Sheathing data group of the Wall Input form. The default is None.
b) Design
For O86-14, the penetration depth used to determine the nail strength described in J: 7.c)iv.4 above is reduced by the thickness of the underlay.
For O86-09 the set of nail lengths listed in the input control and used to cycle through for unknown design does not include nails that do not meet min. penetration depths in table 9.5.1A.
c) Output
A column “GU” has
been added to the Sheathing Materials by Wall Group table showing the gypsum
underlay thickness, with an explanatory legend entry.
9. Nail Slip for Deflection en
The following changes
apply to the calculation of nail slip deflection en, which is one of
the components of shear wall deflection:
a) Wood Structural Panels
For CSA O86-14, instead of the table from O86-09 A.9.7 the program implements the equation from O86 09 A11.7., which depends on the same inputs – spacing s, diameter d, and shear force v.
For green fabrication conditions, the program multiplies the values from the equation by 2.0.
Note that there is no longer an upper limit on the load for which en values are tabulated, so that the program no longer issues warnings in the Design Results that the load per fastener is too high, and has removed this from the list of things that the Design Summary page does not handle.
b) Gypsum Wallboard
Previously, the program used a constant deflection of 0.03 inches = .0762 mm. The O86- 14 design code says to use 0.76 mm. This slight adjustment has been made.
Refer to M: 1 below for changes to restrict the use of GWB to dry service and fabrication conditions.
10. Restricting Materials based on Anchorage
Selection
The Design Setting Materials Restrictions for Anchorages has
been removed from the program, and user interface no longer contains a
restricted set of sheathing thicknesses, nail sizes, or nail spacings based on
these settings. Given the new shear wall design equations based on nail size
and penetration, it is no longer practical to predict ahead of time what
materials cannot be included due to the restrictions in 11.4.5.5 regarding the
applicability of Jhd < 1.
The program now
behaves as if the setting Over-ride hold
down selection to achieve design is always selected. In other words, unless
you have specified in the Wall Input
view that hold-downs are to be used, the program applies hold-downs only where
needed to achieve design, otherwise anchorages are used.
Upon reading project
files from previous versions, the program will reset the materials restrictions
setting to Over-ride hold down selection to achieve design, so that the
behaviour of these projects will change.
11. Gypsum Wallboard (GWB) Design
The following changes
apply to when gypsum wallboard is used as a shear-resisting material.
a) Maximum Percentage GWB for Wind
O86-09 Table 9.5.4 for Maximum Percentage Gypsum Wallboard, which previously applied to both wind and seismic design, has been moved to O86-14 11.8.8, a section that is for seismic design only. Accordingly, for wind design the program no longer calculates the gypsum wallboard percentages, the Maximum Percentage Gypsum table is no longer output, and design failure warning messages no longer shown on the screen or in the results output.
This change has been implemented regardless of whether O86-09
or O86-14 is chosen as the design code, as WoodWorks has been informed that it was always the intention that these
restrictions applied to seismic loading.
b) GWB Percentages for Rd and Ro
=1
A sentence has been added to O86 11.8.8 saying that the Rd and Ro values can each be reduced to 1.0 if the GWB percentages are exceeded. Previously it was an absolute requirement that the GWB percentages not be exceeded. The program therefore no longer displays a Maximum Percentage Gypsum Wallboard table for seismic design if Rd and Ro are both less than or equal to 1.0, outputting an explanatory note instead.
The operation of various screen warning messages and
output warning notes that appear when gypsum wallboard limitations have been
modified to take the possibility that Rd and Ro both
equal 1.0 into account.
c)
Storey Drift
Limitation for Gypsum Wallboard
A sentence has been added to O86 11.8.8 saying that gypsum wallboard does not contribute to seismic resistance if the interstorey drift ratio is greater than 1.0%, that is, if the drift of one storey relative to another is greater than 1% of storey height, as opposed to the 1%, 2% or 2.5% allowed now by NBC 4.1.8.13.(3) according to building type.
To implement this, the program now records the largest drift of any shearline with GWB that is active for design on each storey and force direction. In the storey drift table, if some shearlines on the level/direction indicated have GWB and some do not, for that level/direction the worst case GWB deflection and shearline with the maximum deflection are both output, unless they are the same shearline.
If a shearline fails because it has active GWB and its storey drift is between 1% allowed for gypsum and the percentage allowed for the building type as per NBC 4.1.8.13 (3), then double asterisks (**) appear at the design ratio and a modified failure warning appears.
d) GWB Shear-through-thickness for Deflection Bv
For gypsum wallboard, the shear-through-thickness value Bv has changed from 7005 N/mm to 7000 N/mm, as per CSA O86 11.7.1.2. Previously O86 did not provide guidance for this value, and Shearwalls was using 40,000 lbs/in converted to N/mm. The program still displays 40,000 lbs when imperial units are chosen.
This change is in effect regardless of whether O86-09 or O86-14 is chosen as the design code.
12. Service Condition Factor KSF
The fabrication
moisture content for which any value greater is considered to be green in O86-14
Table 12.2.1.5 and a non-unity factor is applied, has changed from 15% to 19%.
This change has been implemented to the service condition factor applied to
nail withdrawal and shear strength calculations. In addition, the default for
new files has changed from 15% to 19%.
Refer also to K: 14 below Moisture
Conditions Description in Design Settings Input and Output.
1. Unit Nail Resistance Nu for
Anchorage Deflections
The following
problems in determining the value of Nu used in O86-09 9.7.1.1 for the
anchorage component of shear wall deflection, when calculating embedment
strength f1 of the sheathing in 10.9.4.2, were corrected:
a) Yield Mode Equations for Anchorage Deflections
(Bug 2986)
The program erroneously used the value of the dead load component of the hold-down force in N in place of the nail diameter in mm.
If there are no dead loads at the hold-down location, or dead loads less than or just a little more than 10 N, then the program would calculate the wrong f1 value in the yield mode equations, and non-conservatively so. If there are dead loads significantly greater than 10N (which is very small), then the program would not include the yield mode terms that include f1 when determining the hold-down values. That is, it would use yield mode b only. This will also be a non-conservative error in most cases.
This bug interacted with bug 2991, below, which results in very large anchorage deflections, so that if there are significant dead loads, this bug counteracted the other bug so that together they create unreliable results.
b) Sheathing Specific Gravity for Anchorage
Deflections (Bug 2991)
In determining the value of Nu used in O86-09 9.7.1.1 for the anchorage component of shear wall deflection, when calculating embedment strength f1 of the sheathing in 10.9.4.2, the program used sheathing specific gravity values 1/10 of those listed in O86-09 10.9.4.2. They were G = 0.049 for DFP and 0.042 for CSP and OSB, as opposed to 0.49 and 0.42, respectively. This caused anchorage deflections to be roughly order of magnitude larger than they should be, however this varied widely from shear wall to shear wall. This error could also cause forces to the individual shearlines to be distributed to the segments incorrectly in an unpredictable way.
This bug interacted with bug 2986, above, which caused the f1 value never to govern if there were significant dead loads, so this bug would have no additional effect in that case. If there are dead loads, this bug counteracted the other bug so that together they create unreliable results.
2. Shear Wall Capacity Hold-down Method in the
Calculation of Deflections (Bug 2999)
When shear wall
capacity is used as the design force for hold-down design, either via the
design settings or because it is required due to seismic irregularities, this
value was also used to determine the hold-down component of shear wall
deflection. As this is not the intent of the use of shear wall capacity to
ensure sufficient hold-down strength, the calculation for deflection now always
uses applied force to determine hold-down displacement, regardless of the
design setting for hold-down forces or the existence of irregularities.
a) Determination of Irregularities after Redesign
(Bug 2998)
After determining the structural irregularities, the
program if necessary changes the hold-down method to capacity and then
recalculates deflections, redistributes loads based on these deflections, and
sometimes redesigns the structure. However, because hold-down deflections were
based on shear wall capacity, reconfigured building may not have the same
irregularities as before, but the program does not recalculate them. It was
therefore possible that irregularities shown in the output and those that
actually apply to the structure did not match.
In particular, the deflections used to determine Bx,
the torsional sensitivity, were not the same as the ones that are shown in the
output for the redesigned building. It could even happen that the program
determined the building was torsionally irregular, changed the hold-down
setting, and the redesigned building was no longer torsionally irregular.
This situation can no longer occur, because the change in hold-down method to being capacity-based no longer affects deflections.
3. Non-standard Nail Diameters (Bug 2664)
When a non-standard
nail diameter was entered, the program ignored it and used the diameter of a
standard nail with the input length. The
standard diameter appeared in the Sheathing Materials table, and the shear capacity
reduction factor in A9.5.1.2 was not applied. When deselecting the wall then
reselecting it, the standard diameter would reappear.
Non standard nails are now called “power-driven” nails, and
function as intended. The program uses
the nail length and nail diameter in the new design equations for shear wall
shear resistance based on nail strength from O86-14 11.5.1, and the nail
diameter in the design procedure from A9.5.1.2 when O86-09 is selected.
4. Wind Load Storey Drift Table (Bug 3032)
The program now
outputs a Storey Drift for wind
loads, showing the maximum deflection of any shearline for every storey and
direction, and compares it with the limit in NBC 4.1.3.5 3) of 1/500 of storey
height. Note that sentence 4) of this 4.1.3.5 exempts industrial buildings and
sheds, however Shearwalls does not take this into account and outputs a storey
drift table for all structures. Please disregard the table for industrial
buildings and sheds.
A failure for wind
storey drift is output in the Design Summary as one of the new secondary
seismic design checks described in Item 6., below, Special Seismic Checks in Design Summary.
5. Standard Walls and Design Groups
The following
problems related to standard walls, design groups, and the interaction between
them, were corrected:
a) Saving of Standard Walls Modified in Wall Input
View (Bug 3015)
Upon exiting the program, it saved the changes made to Standard Walls that occur when changes are made to walls in the structure while "Design in Group" is checked. Therefore, changes you might inadvertently make while modifying walls could affect the standard walls used for future sessions.
Now, the program asks you whether you want to save the standard walls when exiting standard wall mode and when exiting the program. When exiting the program this prompt only appears if a wall has ever been modified in this way.
Previously, the program saved standard the standard wall file that is used for future sessions when saving a new standard wall, deleting a standard wall, leaving standard wall mode, or selecting a new standard wall in the drop-down list in standard wall mode. It now only saves the standard walls when leaving standard wall mode and when exiting the program.
b) Creation of Standard Wall from Wall in
Structure (Bug 3025)
The Design in Group feature proved to be difficult to implement for a wall that had been created input of walls in the structure rather than via Standard Wall input, because there is no standard wall associated with the wall and design groups are accomplished through standard walls.
For this reason, the program now allows you to create standard walls from regular walls as follows:
When clicking "Edit Standard Walls" while there is a wall selected which does not match any standard wall, the program now asks you if you wish to create a standard wall based on the selected wall. If you create a standard wall in this way, the Design as Group setting is checked for the standard wall and the Design in Group checked for the selected wall.
This feature enhances the program usability in general, similar to the creation of a new font style in a word processor using the font attributes of the selected text.
c) Persistence of "Design as Group"
Checkbox in Standard Wall Mode (Bug 3022)
When you unchecked the Design as Group checkbox in Standard Wall mode, the change is not retained when selecting another standard wall or exiting the box, making it impossible to specify that standard walls are not designed as a group.
d) Standard Wall Name Persistence when not
Designing as Group (Bug 3026)
Sometimes, after selecting a standard wall that is not designed as a group, the standard wall name goes blank in the input field rather than showing the selected standard wall. This has been corrected.
This happened most often when multiple walls were selected and has been corrected.
e) Design as Group for Multiple Identical Wall
Groups (Bug 3026)
When design as group is activated for a standard wall that has the same materials as another standard wall group, the program sometimes assigned individual shear walls to the wrong design group, that is, to a design group for a standard wall group other than the one designated for that wall.
6. Nail Deformation en
for Deflection from O86 Table A.9.7
The
following problems relating the nail deformation en value from CSA O86-09 Table A.9.7 have been
corrected for when CSA O96-09 is selected as the design code. They do not
affect program behavior when O86-14 is selected.
a) en for Larger Nail Sizes (Bug 2583)
When a nail size other than the smallest one
in the table was chosen, the program used an en from the next
smallest standard nail size rather than the nail size selected. This resulted
in a greater than expected nail slippage component of deflection. This problem
did not occur when a non-standard nail intermediate between two standard sizes
was entered; in that case the program correctly selected the lower value.
b) Warning Message for Nails Less then Minimum
Diameter (Bug 3079)
If you entered a nail diameter less than 2.84, the lowest value in the table, the program issued a warning message under the Deflection table in the Design Results about loads per nail being over the highest allowable, even if the loads were within range. The en value used was for the largest diameter and highest loading.
The program now disallows selection of nails less than 2.84 mm in diameter if deflection analysis is turned on.
c) en when Loads Greater than Maximum
(Bug 3079)
If the load per nail was greater than the highest allowable, the program used highest nail slip value for the 3.66 mm diameter nails, or 0.98 mm, not the deflection value for the nail that was selected. As this is the largest diameter, which has the lowest deflection, it creates non-conservative deflections for all other diameters.
Note that a warning message is still issued in this circumstance because even though the en is now for the correct nail size. it corresponds to loading less than what is actually on the nail.
7. Special Seismic Checks in Design Summary
(Change 220)
In the Design
Summary, the program previously reported a list of items that were not included
among the checks being summarized, even though the program made those checks in
the course of seismic design. Now, these checks are reported as having passed
or failed. These checks are:
-
Percentage
gypsum wallboard from O86-14 11.8.8 or O86-09 9.5.4
-
Storey
drift from NBC 4.1.8.13(3) and O86-14 11.8.8.
-
Seismic
Irregularities from NBC 4.1.8.6
-
Over-capacity
ratio from O86-14 11.8.3.2 or O86-09 9.8.3.2
8. Message Box for Gypsum
Wallboard Rd Factor
The following
problems relate to the message box that appears when the Force Modification
factor Rd selected in the Site dialog is not the one appropriate for
the materials used, and have been corrected:
a) Gypsum Walls with Rd Greater than 2 (Bug 2968)
The message box during load generation indicating that an Rd factor of more than 2 should not be used when there are gypsum materials in the structure was not appearing when all the walls with gypsum sheathing had both sides sheathed with gypsum. This has been corrected.
b) Gypsum Walls with Rd = 2 and Ignore Gypsum
Unchecked (Bug 2674)
While generating loads for shear walls with gypsum on one side and the Rd set to 2, the value appropriate to gypsum walls, with the setting for ignoring gypsum unchecked, the program nonetheless issued a message that this setting was active and the offering to either change the Rd value or uncheck the setting.
If you selected "No" to uncheck the setting, the setting remained unchecked program continued to generate loads with the correct Rd value.
9. Percent Resisted by
Gypsum Table
The following problems
related to the Percentage Storey Shear
Resisted by Gypsum Wallboard table used to implement O86-09 Table 9.5.4
have been corrected.
a) Percent Resisted by Gypsum Table when no Gypsum
Present (Bug 3013)
The table no longer appears if there is no gypsum wallboard on the structure.
b) Direction Percent Resisted by Gypsum
Calculation (Bug 3014)
When calculating gypsum and wood capacity only one force direction case was considered: the east-to-west or north-to-south case. Therefore, when the table indicated was displaying results from the south or west direction, it was actually displaying the results for the opposite direction. The program now calculates the percentage shear force in each direction independently.
10. "Improper Argument" error for OSB
Sheathing (Bug 3012)
Upon designing walls
with OSB sheathing with unknown panel marking, sheathing thickness and
non-standard nails selected, an "Improper Argument" error message
appeared and an incorrect Jn factor was calculated, invalidating
design.
This has been
corrected.
11. Elevation View Failure
Message for Passing Walls (Bug 3007)
Elevation view was
sometimes showing the FAILED design message for interior walls even though the
walls passed design. This could happen when you had selected to allow
anchorages rather than hold-downs on the wall, and the design setting was set
to allow the program to "over-ride" the use of anchorages if
necessary and impose hold-downs. This has been corrected.
12. Both Direction Output
in Storey Drift Table (Bug 3018)
In the storey drift
table, the program used to output Both
to indicate, for example that the results apply to both E->W and W->E.
However, this table also includes results from the other orientation, in this
case N->S and S->N, so it was unclear what Both referred to. The program now says e.g. E<->W when indicating the results apply to both directions
rather than Both.
13. Moisture Conditions Label (Change 217)
The notation (%) has been added to the data group
label for the Moisture Conditions
settings, to indicate that the numbers shown are percentage moisture content.
14. Moisture Conditions Description in Input and Output (Change 218)
Adjacent to the input
of Moisture Content in the Design Settings, the program now indicates whether
the value is dry, wet, or green (O86-14), or dry, wet, seasoned, or unseasoned
(O86-09). This is now also indicated in
the Design Results echo of the Design Settings.
15. Extra Null Lines in C&C Design Table (Bug 3035)
For some cases in
which not all of the wall design groups are standard walls, and when only one
of rigid or flexible design is performed, the program prints out an extra line
for each C&C result in the output table with 0 load and 0 capacity,
additional one wall design groups not related to any actual walls are created
with, with 0 load and 0 capacity. These problems have been corrected.
16. Plan View Legend Wording for Failed Walls (Change 177)
The line in the plan
view legend explaining the red color for failed walls now indicates that it is
a “Capacity” failure, to clarify that other types of failures now reported in
the Design Summary are not
highlighted.
1. Duplicate and Missing Low Rise Wind Loads (Bug 3002)
The program would
sometime take portions of low-rise wind loads generated for one corner load
case and assign them to another corner load case, creating duplicate loads for
one case and gaps in the other case. This was most likely to occur if the
structure is heavily indented, and has been corrected.
2. Centre of Mass and Center of Rigidity in Plan View (Feature 218)
The program now shows
the location of the center of loads and the center of rigidity of the
structure, for both wind and seismic loading. These appear in Load Generation action when Rigid forces are chosen for display. Two
small dots with the symbols CL and CR appear.
You can turn on and
off the display of these points using the Show menu.
The distance between
these points in each direction is the moment arm used for torsional analysis
for rigid diaphragm distribution.
3. C&C Wind Loads in Both Directions (Change 176)
When adding a new
C&C load, it is now possible to select "Both ways" for wind
direction, as the program now distinguishes between suction C&C loads for
both nail withdrawal and sheathing strength, and bearing wind loads which
impact sheathing strength only. .
4. Crash Upon Input of C&C Load (Bug 176)
Starting with version
9, after entering a C&C wind load in Load Input form, and if there are no
generated loads, the program would crash upon exit from the dialog. This has been corrected.
5. Update of Add Load
Dialog Input (Bug 3005)
The following
corrections have been made to the Add a
New Load dialogue box:
a) Wind C&C Loads
When Wind C&C is selected,
-
The Apply to... input was limited to Building face but the list was filled
with wall lines. The Apply to input
now shows Wall lines
-
The magnitude labels From and To changed to Interior and End but failed to consistently update back to From and To when a
different type was selected.
b) Apply to Selected Walls
When Apply to…
Selected Walls was selected, the From
and To location did not update
properly so that the load would not be applied to just the extent of the
selected wall.
c) Dead Loads on Building Face
You can no longer apply dead load and building mass loads to an entire building face. These loads are more appropriate to a wall line.
d) Element for Wall Line Loads
For wind shear and seismic loads, the Element was always shown to be Face even when applied to a wall line. It now shows the wall line it was added to.
e) Width of Load List (Bug 3077).
The list of input
loads has been widened to show the Profile
column without scrolling.
6. Missing Elevation View Forces in for No Deflection Analysis (Bug 3003)
When the Design
Setting was set to exclude deflection analysis, the shear flow arrows for
diaphragm shear and base shear and the segment shear force arrows did not show
up in elevation view. This has been corrected.
7. Missing Snow Load Note in Load Generation Dialog (Bug 2988)
Under Seismic Loads in the Generate Loads dialog, the note giving
the percentage of snow load used was missing. It has been restored to the
program.
8. Nonsensical Torsional Forces in Log file for
Low Rise Wind Design (Bug 3006)
Generating low-rise
wind loads on a structure with a flat roof would sometimes show nonsensical
output in the log file for the rigid distribution torsional forces for low-rise
case B wind loads. As these cases have a
net zero wind load in the direction with nonsensical output, this did not
affect design. It has been corrected.
9. Multi-block Low Rise Height to Width Setting (Change 183)
The Design Setting which
indicated whether the structure height-to-width ratios are based on a single
block or multiple blocks has been removed from the program, as it had no
effect. This setting had been put in the
program as part of ongoing development to implement multi-block low rise
procedures; however this feature has not yet been released.
The following changes
have been made to the Design Results output pertaining to wind and seismic load
generation site information:
a) Wind and Seismic Load Generation Procedure
(Change 196)
For design
method, the USA ASCE 7 seismic load generation procedure was showing, and for
wind, the "N" was missing from NBC. These problems have been
corrected and the program now shows the full NBC procedure for both.
For wind design,
the program was showing the choice of low rise (Fig. I-7/8) or all-heights
(FigI-15), but that information is also in the Design Settings output. Instead,
in the Site Information the program now shows Static Procedure from NBC 4.1.7.
b) Cgi Notation (Change 198)
CGI has changed to Cgi.
11. Load Generation Details Results in Log File
The following changes
have been made to the log file showing detailed wind and seismic load
generation information:
a) Log File for New Project (Change 184)
Pressing log file button for a new project displayed the results from the last unsaved session. The log file button is now enabled until loads have been generated.
b) File Header (Changes 187, 179)
The following
changes have been made to the log file header block:
- the date and time now appear at the top of the file instead of each title block of the wind, seismic and torsional analysis information. The unnecessary word “Time:” has been removed.
- the header now includes the version number of the software,
- the program name, version, filename and date are separated by a blank line from the design code information below.
- The header was not appearing if was seismic only loading and thus no wind load generation section. This has been corrected
c) Page Numbers (Change 188)
Since the log
file was placed in a viewer within the Shearwalls program with version 9.0,
page numbers no longer appeared. This has been corrected.
d) Table Alignment in Viewer (Change 214)
The log file was
designed to be shown in Windows Notepad, which has a tab width of 8. The new
internal text viewer uses a tab width of 6, so some output tables were
misaligned with their headers. Tab stops have now been replaced by spaces to
avoid this problem.
e) References to NBC (Change 191)
The references to
NBC design code clauses now follow the format NBC uses when referring
internally to other sections of the publication, e.g. 4.1.7.1.(6)(c) . Previously there had been inconsistent
formatting.
f) Fractional Exponents in Equations (Change 192)
The formatting of
fractional exponents in equations has been changed from fractional to decimal
to conform with NBC formatting, e.g. (h/10)^1/5 is changed to (h/10)^0.2
g) Site Info and Legend Format (Change 189)
Information in
the log file site information and definitions legends that was previously
separated by semi-colons has been placed on a separate line for readability.
h) Formatting of Subsections (Change 201)
Where a
subsection of the report contains more than one simple table, a blank line has
been placed after the heading to the subsection to indicate that all the
information below it pertains to that heading.
i) Wind Load Legend Nomenclature and Formatting
(Change 190)
The following
changes have been made to the legend to the wind load section of the log
file
- Cg – Internal is changed to Cgi - Internal
- P for Pressure has changed to p; also changed in the equation below and column headers
- Commentary 31 changed to Commentary I-31
- LC = Case A or B changed to LC = Load Case A or B in Figure I-7
- Added line Dir = direction (WW = windward, LW = Leeward)
j) References to Ce Equations (Change
193)
The reference to
the equations for exposure factor Ce from the NBC has been made more
exact, changing 4.1.7.1 5) to 4.1.7.1.(5)(a).
and 4.1.7.1.(5)(b). for open terrain and rough terrain, respectively.
k) Main Wind Force vs. C&C Loads (Change 194)
Main Wind Force
and C&C loads have been split into separate tables for readability.
Previously there were two sets of headers for the tables and you had to
correlate information for the type of load being read with the correct header
line.
l) Cei and Cgi Format for
C&C Loads (Change 195)
The internal exposure and gust co-efficients Cei and
Cgi are now output to 2 decimal places instead of 1, similar to Ce
and Ci.
m) Seismic Method (Change 199)
The design code
clause reference has been added to the seismic design method shown in the
header to the section on seismic load generation, and the redundant output of 2
lines repeating the NBC design code under the seismic site information have
been removed.
n) Seismic Site Information
The following
changes have been made to the echo of the user-input Site Information:
i. Seismic Site Information and Legend Titles and Location (Change 200)
The output of Site Information for seismic load generation has been made consistent with wind by removing the words "User Input" and placing it first in the sequence of information reported.
ii. Importance Category (Change 202)
Risk in the seismic Site information section has been renamed Importance category and moved to be adjacent to the Importance Factor Ie.
iii. Fv Formatting (Change 203)
The extra spaces before the output of Fv in the seismic Site Information have been removed.
iv. Ta and Rd,Ro in Seismic Site Information (Change 205)
The
seismic site information now indicates whether the Ta used is from the
equation listed below or from the user input over-ride, and indicates that the
value is shown in the Base Shear table. It also indicates that Rd and Ro
are in the Base Shear table, in order to make it clear that these values
are input and not calculated.
o) Seismic Legend (Changes 210-211)
The following
changes have been made to the Symbols section
for seismic load generation
- This section has been renamed Legend, consistent with Wind output.
- The definition of Vx has been removed, as it does not apply to NBC design.
- For Fx, design seismic force… has changed to "lateral force... so that it matches NBC usage.
- wi and wx are changed to Wx and Wi for consistency with NBC notation
p) Seismic Equations (Change 204)
The following
changes have been made to the Equations section for seismic load generation:
-
The
definitions have been removed from in front of V, Ta, Ft and Vx since these are
already supplied in the Legend section.
-
Segment Lateral Force: Vp and Top
Storey Shear Force: Vn have been removed, as they are from old design code
editions and are now obsolete.
-
The
words hn in m have been added to the
expression for Ta to indicate for imperial output that that expression
is valid only when Ta is in metric units.
-
wi and wx are changed to Wx and
Wi for consistency with NBC notation.
q) Calculation of Base Shear Table (Change 212)
The following
changes have been made to the Calculation of Design Base Shear section:
-
The
value of hn, the height of the top level, is now shown below the Calculation of
Design Base Shear
-
The
notation T has been changed to Ta, for consistency with NBC and the
rest of the report
-
The
notation S has been changed to S(T)
r) Distribution of Base Shear to Stories (Changes
206-209, 212)
The Distribution of Base Shear to Stories table often appeared in a puzzling, ragged format because an earlier format with the stories arrayed horizontally was shown along with the current format with the rows arranged vertically. This has been corrected, and the following changes have also been made:
- When you chose in the Format Settings to show distances in feet and inches, the table would show the storey height that way rather than in decimal format, which is used for all output reports.
- The final column is now headed by Fx instead of Vx, in keeping with NBC terminology
- The name of the table has been changed to Distribution of Base Shear to Levels, to avoid the complication of differing spelling of the word storey for USA and Canada.
1. OSB and GWB in Wet Service Conditions (Bug 3000)
Oriented strand board
(OSB) and gypsum wallboard (GWB) are no longer allowed for wet service
conditions, as these materials are not permitted for wet service conditions
according to O86-14 9.4.2 and Table 11.5.4 Note 2, respectively. When you try
to add one of these materials to a structure for which wet service conditions
is set, the program disallows the entry. If such materials exist in the
structure, the program disallows entry of in-service moisture content greater
than 15% (O86-14) or 19% (O86-09). An on-screen explanatory warning is issued
when the program rejects a change.
The program also
changes the in-service moisture content from existing files, when opened, if
GWB or OSB is used anywhere in the structure.
Because CSA O86
A.11.7 for gypsum wallboard nail slip deflection en is for dry
fabrication conditions only, changes resulting in these GWB along with green
fabrication conditions and deflection-based force distribution cause the
setting for ignoring non-wood-panel materials for design to be set. If the setting for deflection-based force
distribution is not set, the program allows green fabrication conditions but
issues an on-screen message and a warning under both the Deflection table and the Storey
Drift table in the Design Results.
2. Plywood Sheathing Plies (Bug 2994)
The following
problems relating to the selection of plywood sheathing plies in the Wall Input
view have been corrected.\:
a) Available Plies
Not all the selections for plywood sheathing plies from tables 7.3A and 7.3B were available for each thickness. In particular, 3-ply 12.5 and 6- ply 15.5 were not included. These had been added for CSA O86-09 but not incorporated in the software until now.
b) Default Plies
When the thickness is changed, the program now defaults to
the no. of plies for the most commonly available material as shown by the
asterisk in Table 7.3A and 7.3b
3. Custom Plywood
Thickness (Bug 2994)
The following
problems occurred when custom plywood thicknesses were entered, rather than
using a standard value from the list. This is not recommended and rarely done
because such thicknesses are not available commercially. They have been corrected,
nonetheless.
a) Ply
Selection
After typing in a custom thickness for plywood, the
selection of plies remained the same as for the previously entered standard
thickness. The program now updates to show plies that are available for the
closest standard thickness that is smaller than the entered custom thickness.
b) Zero Bv
When determining the shear-through-rigidity thickness, Bv,
for the shear deflection calculation in O86-09 9.7.1.1, the program would
sometimes use a value of zero for Bv because the number of plies was
invalid for the next smallest thickness. This caused the vHs/Bv term to be undefined in the
deflection equation.
c) Bv for Sizes Greater Than 18.5mm
There exist values in Table 7.3A and 7.3B for
shear-through-thickness rigidity Bv for panels thicker than 18.5mm,
but if a custom thickness is entered that is larger than 18.5 mm, the program
still used Bv values associated with 18.5mm that were as much as 60%
smaller than in reality. Note that the use of panels greater than 18.5 mm is
exceedingly rare.
d) Upper
Limit on Sheathing Thickness
You could type in sheathing values greater than 31.5, the largest for which values exist in Tables 7.3A and B. Since such plywood does not exist in practice, the program now limits input to 31.5 mm.
4. Nail Penetration
Imperial Unit Format (Change 180)
The nail penetration
shown in the Sheathing Materials table is now formatted as a decimal instead of
as a fraction when in imperial units.
5. Nail Diameter Format (Change 219)
For non-standard (now
power-driven) nail input in Wall Input view and output in the Sheathing
Materials table, the program now shows the millimeter value with 2 digits
precision, without truncating trailing zeroes, e.g "3.00" instead of
"3'.
6. MSR Grade Design Note
(Change 215)
The Note 7 giving the
MSR grade under the Sheathing Materials table in the Design Results output has
been eliminated, and instead, under Species
if the framing material type is MSR or MEL, the word “MSR” or “MEL” appears in
front of the species name. The eliminated note had the following problems:
-
It was
under the Sheathing Materials table but should have been under the Framing
Materials table.
-
It output
the E grade for MSR, but since deflection design was implemented, that value
was added to the Framing materials table.
-
It said
“MSR” even if it is MEL. There was no way of knowing it was MEL.
-
It repeated
itself unnecessarily.
-
It should
have said “for framing members”, not “as framing members”.
7. OSB Panel Marking
Design Note (Change 216)
The Note 8 giving the
OSB panel
marking under the Sheathing
Materials table in the Design Results output repeated itself for every wall
with the marking, which defeated the purpose of creating the note. This has
been corrected and it now outputs out each marking M1, M2, or M3 just once.
1. Extend Upwards Operation (Bug 3073)
In extending upwards
in stages, the program created an extra level on the level above the one you
selected to extend to and uses the original block outline to create that level
instead of the modified footprint. You could then only extend from that level
upwards. For example, extending to level
2 on a 4-storey structure, the program copied the modified footprint to level 2
and added the original footprint to level 3, and placed you on level 3. If you extend to a level below the top, the
extra level was placed on the topmost level and the process was complete.
This extra level is
no longer added when extending levels in stages, for example if you extend to
level 2, the program merely copies the modified ground floor level to level 2
and places you there to proceed.
2. Settings Dialog for Medium and Large Display Size (Bug 3068)
It was sometimes not
possible to view all the Settings input tabs when medium or large Display Size was selected in Windows. In
particular, it could happen that you were unable to click the buttons at the
bottom that close the boxes.
These boxes have now
been reorganized in a shape similar to that of a typical computer screen, so
that the entire box fits in the view regardless of the display option selected.
3. “Getting Started” Steps Display (Change 181)
The list of steps
helping you to get started using the Shearwalls program has been placed in a
scrollable view and formatted with bold titles for each step. The number of
steps had become too large to fit on the screen without a scroll bar.
The following changes
have been made to the main toolbar:
-
Results View has been renamed Design Results.
-
Design Results has now been grouped with icons for detailed
output for load generation and torsional analysis (formerly Log file) and the
new Detailed Shearwall Design output
-
Design Results has now shows rectangles representing tabular
data to differentiate it from the detailed text results.
-
Form View has been changed to Input Form.
5. WoodWorks Sales and Technical Support Contact Information (DO Change 6)
In both the Key code Registration box and the Help About box, we have
-
removed
word Support from "Sales Support”.
-
asked
users to provide company name rather than address.
-
removed
fax as a means of communication.
-
emphasized
email instead of phone as a means of contact.
-
changed
the email address to be a link that opens an email message.
6. Parentheses in the Help About
box (DO Change 7)
Where parentheses
were used in the Help About, the
closing parenthesis appeared inverted at the start of the line instead of where
it should have been. These occurred around things like the date of publication
and the relevant parts of design code publications, and have been replaced with
a dash as a means of delineating them.
7. Apply Button in Settings Dialog (Change 185)
The “Apply” button
has been removed from the Settings dialog because it had no effect.
8. Update of Roof Overhang Input (Change 186)
In the roof input
form, the roof overhang values were being set to zero when switching from a
flat roof to a sloped roof and back again. They are now restored to their
previous values.
9. Image File Wording in Message (Change 182)
In a message saying
that the CAD file had not been imported, the words Windows metafile have been changed to image file, as several types of images are now imported.
10. Typo in Out-of-date Design Message Box (Change 178)
The repeated word
“design” has been removed from the message box that appears telling you that
your structure has changed, and your previous design is out of date.
Shearwalls 9.2.1 Hot Fix –
March 16, 2015
This version was
sent to individual users to address Bug 3002 - Duplicate and Missing Low Rise
Wind Loads, which is listed under Version 9.3, the first version distributed to the general public with this fix.
Shearwalls 9.2 –
November 19, 2014 - Design Office 9, Service Release 2
1. Upper Level Failures In Hold-down Design
Summary (Bug 2948)
The Hold-down Design table of the Design Summary output was reporting
walls as having failed hold-down design for multiple building levels when it
only failed hold-down design on the lowest level listed. This has been
corrected.
2. Duplicate Wall Wind Shear Loads for Additional Roof Blocks (Bug 2946)
After additional
blocks are created for roofs only, with no attached walls, the program was
creating a duplicate set of wall wind shear loads for walls on the other
blocks. For multi-storey buildings this was happening on all levels except the
top level.
If the project file
was saved and then re-opened and then loads were re-generated the duplicate
loads were no longer being created. This has been corrected.
3. Crash on Accept Design for Exterior
Non-Shearwalls (Bug 2934)
When there were
non-shearwalls on the exterior of the building with C&C loads, Shearwalls
would crash when the Accept Design
button was pressed. This has been corrected.
4. Crash After Deleting Additional Roof Block (Bug 2947)
After additional
blocks are created for roofs only, with no attached walls, and wind loads were
generated on these blocks, then one of these blocks is deleted, the program
would sometimes crash the next time you tried to save the file, re-generate
loads, or run design. This has been corrected.
5. Plan View Freeze for Exterior Non-Shearwalls
showing Design Group Numbers (Bug 2935)
If you elected to
show the design group numbers for each wall in Plan View via the Show menu, the drawing would not be
updated if there were non-shearwalls on the exterior surface of the building
with C&C loads. The Plan View drawing would freeze up until you disabled
this option. This has been corrected.
6. C&C Design Results for Non-shearwalls on Exterior Walls (Bug 2937)
The Components and Cladding table in the Design Results was not including results
for exterior shearlines which had only non-shearwalls on the line. This has
been corrected and results now appear for these walls.
7. Materials Output for Non-shearwalls on Exterior Walls (Bug 2936)
The Sheathing Materials and Framing Materials by Wall Group tabled by in the Design Results were not
including results for exterior shearlines which had only non-shearwalls on the
line. This has been corrected and results now appear for these walls.
8. Wind Suction Title (Change174)
The title in the
program output "Wind Suction Design" has been changed to
"Out-of-plane Wind Design". This is because the governing condition
can be either suction or bearing of wind.
9. Ctrl-C Operation (Bug 2964)
Previously pressing
Ctrl-C caused a file close, when the standard operation that users expect is to
copy selected text in an edit control, leading to significant frustration. This
has been corrected and Ctrl-C now copies text and there is no shortcut for
closing a project file. .
Shearwalls 9.1 –
October 29, 2014 - Design Office 9, Service Release 1b
1. Accept Design for Existing Files (Bug 2903)
For saved project
files, the Accept Design button was
defaulting to accept flexible wind design, instead of the currently selected
load case and distribution method. If there were no wind loads the Accept Design button had no effect. This
has been corrected.
2. Inconsistent Design Results on Consecutive Runs for Capacity-based
Distribution (Bug 2904)
The program was
producing different rigid load distributions and wall designs on consecutive
design runs for the Use shearwall
capacity to approximate rigidity rigid distribution setting. None of the
design runs could be assumed to be correct due to instability in the updating
of segment rigidities. This has been
corrected.
3. Relative Rigidity in Wall Input View after Accept Design (Bug 2909)
After pressing the Accept Design button the relative
rigidity in the Wall Input view was showing 1.0 instead of the rigidity from
the accepted design wall.
This is just a
display issue and the correct rigidity was used in design. It has been
corrected.
4. Gypsum Wallboard Shear Rigidity Bv in Design Results (Bug
2911)
When imperial units
are used, the shear rigidity Bv value for gypsum wallboard shown in
the sheathing information table of the design results was the correct value
divided by 12. This was a display issue
only and did not affect design. It has been corrected.
Note that this value
comes from the USA SDPWS in the absence of Canadian guidance.
5. Rigidity Shown in Wall Input for Redundant Wind Directions (Bug 2913)
When the Wind
directions S->N, E->W and N->S, W->E are selected in the
Show menu, the Rigidity shown in Wall Input view was a nonsensical value. This
was a display issue only and the correct rigidity was used in the shear wall
design. It has been corrected.
6. Non-shearwall C&C Failure for Rigid-only Design (Bug 2919)
If only rigid
diaphragm analysis is selected in the Structure Input view, the program shows
failure for non-shearwalls in elevation view, even if the walls are strong
enough to resist design. In the Components
and Cladding table, the program showed a warning that these walls do not
have shear resisting materials, even If they did.
This problem
disappeared if you chose to do both rigid and flexible design. It has now been
corrected.
7. Zero Magnitude Wind Load Generation for Flat Roofs (Bug 2922)
Occasionally when
wind loads with zero magnitude were generated on single faces of buildings with
flat roofs. This problem occurred only sporadically and has been corrected.
8. Selection of Standard Walls that Differ Only by End Studs (Bug 2923)
When selecting a
standard wall to assign to a physical wall, the number of wall studs was not
being accounted for, so that if there were two standard walls that were
identical except for the number of wall studs it sometimes would cause the
program to assign the wrong standard wall to the selected wall. It was also not
possible to select one of the standard walls in the Edit standard wall view.
Whether or not it
happened depended on the order of the near-identical standard walls in the list
of walls. It has been corrected.
9. Redundant Design Groups with Differing Penetration Depths (Bug 2924)
Sometimes extra,
unnecessary design wall groups were being created with a nail penetration depth
1mm larger than another wall group, when the walls should actually be in the
same wall group and have the same nail penetration depth. This occurred only
sporadically and has been corrected.
10. Unknown Values on Interior Wall Surface (Bug 2925)
In wall input view,
if you selected "Both sides the same"
and specified unknown values, and then deselected Both sides the same, the unknown values were still recorded in the
interior sheathing, even though design for unknowns is not done independently
for interior sheathing. If these unknown values were not changed, the program
would design using the weakest materials in the list, and would show question
marks (?) in the Wall Design Groups
output table for the interior sheathing.
Now, when you
deselect Both sides the same, the
program changes any unknown values on the interior surface to the weakest
possible. Unless changed, these
materials now show up in the Design Group Output.
11. Crash for Failed Walls with Non-shearwall Shearlines (Bug 2926)
Starting with version
9, the program would sometimes crash after designing a structure in which some
wall lines are entirely non-shearwalls, and some other lines have walls do not
have sufficient shear capacity to resist the applied force. This has been
corrected.
12. Program Version for Saved Files (Change 173)
The program now
records the version of the program used to save a project file and shows it in
the About Shearwalls box when the file is opened. This feature is primarily
used internally at WoodWorks for diagnostics.
Shearwalls 9.0.1
– October 8, 2014 - Design Office 9, Service Release 1a
1. Persistence of Manually Input Wall Rigidities (Bug 2895)
Starting with version
9, when manually input rigidities are selected as the rigidity method in the
Design settings, the program re-set all relative rigidities to one when
distributing loads.
Since load
distribution is done before design, it was no longer possible to set manual
rigidities that are then used in design, and the manual option was identical to
the “equal rigidities” option. This has been corrected and the program again
allows you to manually set the rigidity to be used for each wall in the
structure.
2. Relative Rigidity as Parameter for Design as Group (Bug 2897)
If you change the
manually input relative rigidity for one wall in a standard wall group, the
program no longer applies it to all walls in that group, nor does it present a
message box warning you of this. Instead, different walls within different
groups can have different relative rigidities.
Note that when the
Design Setting All shearwalls on
shearline have same materials was set, the program did not apply the
relative rigidity to all walls within a line walls in a line. The behaviour for
design groups is now consistent with that approach. Rigidity usually depends on
the geometry of the wall so it cannot be specified for all walls within a group
or line containing walls of differing lengths.
The program still
includes relative rigidity amongst those parameters in a Standard wall that can
be used to create the initial values for a set of walls. However, it no longer
includes rigidity among those parameters that define a standard wall when identifying
what standard wall a physical wall pertains to.
Shearwalls 9.0 – Oct 1, 2014,
Design Office 9, Service Release 1
This release
corrected the problem with the Design Office installation that disabled the
input of .pdf CAD files (Feature 126).
No changes were actually made to the Shearwalls program itself, hence
the same version number as the previous version, 9.0.
Shearwalls 9.0 –
Sept 17, 2014 - Design Office 9
This is a major
release of the software containing many new features and small improvements.
The following table
of contents can be used to navigate to detailed descriptions of the program
changes.
2. Wall Design Groups (Feature 17)
3. Highlight of Failing Walls
(Feature 75)
4. Design Summary (Feature 138)
5. 500mm Stud Spacing for Unblocked Factor (Feature 173)
6. Hold-down Offset Subtraction from Overturning Moment Arm
(Bug 2731, Change 165)
7. Hold-down Force Accumulation Tolerance ( Change 169)
8. Non-convergence of Deflection-based Distribution to
Segments (Bug 2770)
9. Uplift Loads on Walls with Openings (Bug 2744)
10. Verification of Stable Design in Final Design Check
Iteration (Bug 2743)
11. Design for Distribution of Forces to Shearwall Segments
Based on Rigidity
12. Output Warnings for Inadequate Stud Thickness for
Hold-downs (Bug 2825)
13. Hold-down Stud Width for Capacity and Elongation
(Bug 2826)
14. Levels and Directions for Out-of-Plane and Weak Storey
Seismic Irregularities (Bug 2824)
15. NBCC Terminology (Change
164)
B: Building Model and Program
Operation
1. Design and Load Distribution Processing Time
2. Multiple Extend Upwards (Feature 193)
3. Accept Design (Feature 153)
4. Log File in Viewer (Feature 153)
5. Log File Button (Change 120)
6. Getting Started Steps (Change 122)
7. Crash after Moving
Opening then Entering One (Bug 2856)
8. Creation of Perpendicular Non-shearwalls (Bug 2880)
9. Location of Standard Walls File for Network Installations
(Bug 2776)
1. List of Cities for Default Seismic and Wind Data (Feature
209)
4. Crash on Load Generation for Closely Spaced Walls (Bug
2687)
5. Crash when Generating Loads on Merged Walls (Bug 2882)
6. Torsional Irregularity for Wall Lines with Zero FHS (Bug
2738)
7. Message for Applicability of I-15 Method for Multi-block
Structures (Bug 2738)
8. No Species Group in Initialization File (Change 2738)
D: Drawings and Graphical
Input
1. Import of Bitmap and PDF Versions of CAD Files (Feature
126)
2. Adding Openings over CAD Import (Feature 150)
3. Graphical Selection of Openings (Feature 23)
4. Display of Wall Group Name (Feature 102)*
5. Slowdown in Updating the Drawing of Loads (Bug 2750)
6. Appearance of Load Arrows (Bug 1952)
7. Color of Text in Load Generation Legend (Bug 2815)
8. Plan View Update Quality (Change 161)
1. Standard Wall Copy (Feature 178)
2. Default Load Type when Adding
Loads (Feature 141)
3. Creating Standard Walls with Unknowns (Bug 2881)
4. Default Thickness for OSB Sheathing. (Bug 2805)
5. Unknown OSB Interior Panel Markings (Bug 2881)
6. Conversion of Imperial Units for Wall Framing Thickness
(Bug 2804)
7. Tool Tips for Wind Load Generation Controls (Bug 2675)
8. Input of Invalid Wall Location (Bug 2754)
9. Editable Ply and Panel Marking Input Box (Bug 2807)
10. Enabling of Double-Bracket Boxes in Openings View (Bug
2813)
11. Wall Framing and Hold-down Behaviour on Multiple
Selection (Bug 2816)
12. User Interface Rearrangement
14. Default Setting for Save as Default (Change 159)
15. Location of Wall Dead Load Input (Change 153)
16. Project Files With Hold-downs Deleted from Database
(Bug 2827)
17. Message for No Species Group in Database.ini File
(Change 167)
1. Shear Results Output for
Shearlines which Extend over Part of Structure (Bug 2822)
2. Cumulative Storey Shear in Seismic info Table (Change 137)
3. Shearwall Wall and Opening Dimensions Table Legend (Change
162)
4. Component and Cladding Tables Design Tables (Nug 2885)
5. Output of Bx
for Torsional Irregularity (Change 154)
6. Design Code Clause in Irregularities Table (Change 152)
7. Code reference for Gust Effect Factors in Log File (Change
166)
8. Panel Marking in Sheathing Materials Output (Bug 2808)
9. Log File for Torsional Analysis Changes (Changes 138-141)
10. Shear Design Table Legend (Change 172)
11. Default Design Results View (Change 155)
12. Blank Page in Output (Change 157)
13. Capitalization of Load Case (Change 142)
Previously, when wall
parameters were left as unknown, Shearwalls designed separate walls for wind
design, seismic design, rigid distribution, flexible distribution, and both
force directions – a possibility of 8 designed walls for each physical wall in the
structure. In practice, at most 4 walls would be designed, because forces in
opposing directions are similar, and often only two or three walls would
result. It was left to the designer to compare these walls manually and choose
the one that was strong enough for all load cases. If you wanted to see design
results for the selected wall, it was necessary to “accept” the design for that
case and to run the design again.
Now, the program
automatically determines the worst case of wind and seismic, and for opposing
force directions, and designs one wall that is evaluated for all these load
cases. Optionally, you can also have the program determine the worst case of
rigid and flexible diaphragms.
a)
Worst Case Wind
vs. Seismic Load Case (Feature 12)
i. Shear Wall Design
Previously, the program determined the wall parameters needed to resist the forces from the applied wind loads, and then did so for seismic loads separately. As a result, the program could create separate wall groups for the same physical wall, one for wind design and one for seismic design.
The program now compares the walls designed for wind and seismic and selects the wall that has the highest capacity. That wall is then used to redistribute forces on the line if deflection is the force distribution criterion, and to redistribute forces to the shearlines for the rigid diaphragm procedure.
ii. Output – Shear Design Table
The wall groups are indicated by numbers in the Shear Design table, which are defined in the Sheathing and Framing Materials by Wall Group tables. For a particular wall, the same number now appears for seismic and wind design; previously they could be different.
In the Critical Response column of the table for wind design, the program outputs an “S” beside the response ratio if the critical case was seismic and the wall had unknown parameters. Similarly, a W is printed beside the column in the seismic table if the critical case was wind. This alerts you to the reason that a wall might be designed with materials that are much higher than needed to resist the loads from the design case shown.
The legend has been modified to explain the meaning of these letters.
b) Worst Case Rigid Diaphragm vs. Flexible
Distribution Method (Feature 69)
Many designers prefer to consider diaphragms to be semi-rigid, and in the absence of a complex numerical model of the structure, wish to design for the worst case of rigid and flexible diaphragm distribution, to cover the whole envelope of possible diaphragm rigidities. Shearwalls now allows for that approach.
i. Design Setting
A checkbox has been added to the Design Settings called
Worst-case
rigid vs. flexible diaphragms (envelope design).
The default for new program installations that this setting is on, but this can be changed. The setting is disabled if you have not chosen to design for both rigid and flexible diaphragms (the choice is in the Structure input).
ii. Shear Wall Design
If the Worst case rigid vs. flexible setting is not selected, program determines the wall parameters needed to resist flexible diaphragm distribution forces, and then does so for rigid forces separately. As a result, the program can create separate wall groups for the same physical wall, one for rigid diaphragm design and one for flexible design.
If the setting is selected, the program first designs a wall for flexible diaphragm forces. When designing for rigid forces, if they are lower than flexible force, the program simply uses the wall designed with the flexible force. If they are higher than the flexible force, it replaces the wall designed for flexible forces with the one designed for rigid forces. For deflection-based intra-shearline distribution, the wall is then processed again for flexible forces on the next iteration of the design procedure, as the distribution of forces within the shearline may change slightly due to the new wall stiffness.
iii. Output – Shear Design Table
The wall groups are indicated by numbers in the Shear Design table, which are defined in the Sheathing and Framing Materials by Wall Group tables. If you have selected the Worst-case rigid vs. flexible diaphragms design setting, then for a particular wall, the same number appears for rigid and flexible design. If that setting is not selected, they can be different.
Please note that if the Worst case rigid vs. flexible setting is set, a the wall materials appearing in table for rigid diaphragm design may have been designed for a higher force for flexible diaphragm design, and vice-versa. If the program designs walls that appear to be much stronger than needed, this is the most likely reason.
c) Worst Case of Opposing Force Directions
It is possible for the force in one direction to be slightly different than the force in the opposing direction. For wind design, this can occur for a mono-slope roof or eccentric ridge line. For both wind and seismic design, it can occur when forces are distributed due to deflection and there are asymmetries in the hold-down devices or hold-down forces. An example of this is when openings are do not line up and vertical compression forces from the floor above are added to tension forces from the floor below.
In rare circumstances, such difference could cause the program to design a different wall for the east->west direction than the west<-east direction, and similarly for north-south walls.
i. Shear Wall Design
The program now determines the largest force on any segment in the shearline, in either direction, and designs the wall materials for that force.
ii. Output – Shear Design Table
When different forces existed, two lines of results instead of one were output in the Shear Design table for each wall in the shearline. If different wall materials were selected by the program for these forces, a different wall design group number could be shown for the two directions.
The program still outputs separate design results for the opposing force directions if they are different, but this is to show the performance of the wall with respect to the different forces. The design group number shown for the opposing directions is now always the same.
d) Worst Case of Wind Shear vs. Wind C&C Design
(Bug 2848)
In determining
the worst-case wall on the structure, the program considers wind shear, nail
withdrawal, and C&C sheathing design.
The procedure has one slight imperfection in that thicker sheathing, which is optimal for out of plane sheathing strength and for shear design, makes for weaker nail withdrawal strength due to reduced penetration. So when determining the strongest wall, one wall may be stronger for suction and for shear but another may be stronger for nail withdrawal. In such a case, the program uses the wall with thicker sheathing. It is extremely rare for the wall to fail for nail withdrawal as a result.
There exists a small possibility that when distributing loads using the rigid diaphragm method to a stronger wall than was designed using that method, the rigid distribution routine could load the shearline to the extent that the wall fails despite being stronger than the one that previously passed. This can happen when a wall designed for seismic is used to resist wind loads (or vice versa), or when a wall designed for flexible distribution is used for rigid diaphragm forces.
Although unlikely, it has the highest chance of happening when using deflection-based design and the effect of increased stiffness is greater than the increase in wall capacity.
If this occurs, the program alerts you to the situation
via a note under the Shear Results
table. The wording of the existing note that appears if this occurs for other
reasons has been modified to take into account this possibility.
The same thing could conceivably happen for the flexible diaphragm method and
distribution within a shearline using
deflection-based rigidity, but it is highly unlikely because all segments on
the wall have the same shear wall materials.
f) Shearline, Wall and Opening Dimensions Table
Because this table no longer shows a list of design groups for each wall, showing at most two for rigid and flexible design, the heading to this column is “Wall group rather than Wall Group(s). A note below the table has been added when worst case rigid and flexible is not selected, explaining why two group numbers may appear.
2. Wall Design Groups (Feature 17)
The program now
allows you to specify that groups of walls with unknown parameters wind up with
the same material specification after design. The program designs the wall for
the most heavily loaded wall in the group.
For example, all
interior walls on a certain level, or all exterior walls in the structure, can
be specified to be the same. Previously such walls would often have slightly
different material specifications, which is not usually practical for
construction.
The program uses the existing Standard Wall mechanism for this feature. You can indicate which standard wall groups are to be designed as a group, and within the standard wall group, which walls are to be included in the group design. It may be necessary therefore to make more standard wall groups than were previously used to make default walls.
For example, if you had a Standard Wall called Exterior Shearwalls that was used as a starting point for design of all exterior walls, but want the same set of wall materials to be designed on each story of the structure, but possibly lighter walls on the upper storeys, then you would make 4 new groups called Exterior Shearwalls Lev 1, Exterior Shearwalls Lev 2, etc.
A checkbox has been added to the Standard Wall input called Design as a group and in the regular wall input mode called Design in group. The checkbox in the standard wall mode means that all the walls of that standard wall that also have the checkbox checked will be designed as a group in the sense that they will wind up with identical materials after design. Those individual walls that do not have the checkbox checked are treated as if they were not part of a standard wall group. Those standard walls that do not have the checkbox checked function as current standard walls, that is, as default walls only.
i. Default Setting
The standard wall checkbox will default to being checked if a new standard wall is made. The standard walls shipped with the program will have the checkbox checked by default.
ii. Updates
If you uncheck the Design as a group check box for a standard wall, then all the checkboxes for walls of that group are unchecked and disabled. If you check a standard wall box that had been unchecked, then all of the standard walls in the program are be checked and enabled.
If you select a Standard Wall for an individual wall when previously it had a different standard wall or no standard wall, then the individual wall’s checkbox will be checked and enabled if the standard wall box is checked. If it is not, it is unchecked and disabled.
If you change a wall so that it becomes identical to a standard wall and then becomes one of those standard walls, the checkbox will be unchecked regardless of whether the standard wall Design as Group checkbox is checked or unchecked, but it will still be enabled. This is because the wall was not made a standard wall deliberately, so you are unlikely to want it to be grouped with those walls for design.
iii. Default Walls
When walls are made in the program using standard walls, then the individual wall’s checkbox will be checked and enabled if the standard wall box is checked. If it is not, it will be unchecked and disabled.
iv. Standard Wall Deletion
If you delete a standard wall, then the program goes through all the walls that had been that standard wall, and unchecks Design in group.
v. Previous Versions
Walls from existing files from versions before the feature was implemented have their individual wall Design in group checkbox unchecked by default.
Previously, when attributes such as materials or wall type were changed for individual walls, the wall would no longer be identified as being a standard wall. If standard walls are changed, then all the walls that were created with that wall were not identified with that standard wall. For those standard walls designed as groups, this has changed, and membership in the standard wall group persists through material changes.
i. Change of Wall Attribute
If you change an attribute of a wall that is currently one of a standard wall group, and both the standard wall and the individual wall are to be part of a design group, then the program will issue a warning saying, All walls of the [standard wall group] will also have the selected change. There is a “Don’t show this box again checkbox in the message to allow you to avoid having the box appear repeatedly.
If you don’t want the attribute to change for all walls in the group, then just change it back to what it was and deselect the Design in Group box for those walls you do not want to change.
If you change an attribute of a wall that is a standard wall but does not have the Design as Group checkbox checked, then the program will allow the change with no message and in most cases it will cause the wall to no longer be part of the standard wall group. No other walls will receive the change.
ii. Change of Standard Wall Attribute
If you change at least one attribute of a wall that has the Design as Group box checked, when exiting the box, the same message as for individual walls appears, saying all members of the Standard Wall group will receive the change, allowing you to suppress further instances of the message.
If the Design as Group box is not checked, then a change in wall attributes will cause all the walls that were previously one of the standard walls to no longer a standard wall, as the program currently behaves.
d) Multiple Standard Walls with Same Materials
Previously, the program would not allow you to create more than one standard wall with the same material specification. For those standard walls that are designed as a group, this restriction has been relaxed in order that you can use for example the same material specification with unknowns that become different wall specifications when the unknowns are determined by the program in order to meet design requirements.
For example, you can have different standard wall groups on each floor of the building, each with the identical materials when unknowns are included, which however become different walls when the program designs for the different loading scenarios on each floor.
i. Automatic Identification of Standard Wall Group
Currently, if the program identifies that a change in a wall makes it identical to a standard wall, it assigns it to that standard wall. If you have multiple standard walls with the same specification, it randomly chooses which of these standard walls to assign the wall to. This has little impact, because the Design in group is unchecked in this case. You can manually change the standard wall the wall is associated with and check Design in Group if you want it to be grouped with a different wall.
e) Standard Wall File Synchronization
When a file is saved with standard wall groups, and the standard wall definitions are later changed, or standard walls are deleted, while in another project, and the original file is opened up again, some of the grouped walls have no standard wall associated with them.
If this happens, new standard walls are created with the materials from the grouped walls, and given names Std Wall 1, Std Wall 2, etc. These walls are later saved as standard walls that can be opened with any project. You can then either delete them, rename them, or reconcile them with the changed standard walls that were originally used to create them.
After the design iterations, and before the final design check, the program compares the design capacities of all walls in a group. I then the materials of the wall with the highest capacity to all the walls in the group, then recalculates the wall deflections, redistributes loads to the walls, and outputs design tables for the new walls.
i. Design Failure
It is possible for the new load distribution to create a situation that the critical wall in the design group might elsewhere fail elsewhere on the structure where a weaker wall had passed. When this happens, a warning appears in the Shear Design table of the output. The existing warning that appears when this occurs for other reasons has been reworded to reflect this possibility,
ii. Wall Grouping
The existing system of comparing all the designed walls to establish design groups with identical materials, which are identified by numbers, has been retained. The fact that walls within a Standard Wall group will have the same materials cause them to be grouped with the same group number.
Walls that are not part of Standard Wall groups are also grouped and assigned group numbers as they currently are.
Changes have been made to the recently added Accept Design feature because there are no longer separate designs for wind and seismic, so the choices in the selection menu are now just Rigid Diaphragm and Flexible Diaphragm” rather then Rigid, Wind, etc.
The sub-submenu item has been changed to say Accept from Accept Design.
When you have activated the Worst Case Rigid and Flexible feature, both Rigid and Flexible are checked but disabled, and the Accept item is the only one that is enabled.
i. FRAMING MATERIALS by WALL GROUP Table
The name of the Standard Wall associated with a wall group, if there is one, is included in a column that has been added to this table. It is possible that more than one Standard Wall yields the same materials when designed; in that case the line is repeated with the same group number. If there is no Standard wall associated with the group number because it came from walls that were not grouped, the line appears blank.
The table has been renamed accordingly to FRAMING MATERIALS and STANDARD WALL by WALL
GROUP.
ii. SHEAR DESIGN Table
A hat symbol (^) appears beside the wall group number for the wall that is critical for that group, that is, the wall that had the heaviest loading and for which the wall materials designed were used for all other walls in that group.
The legend has been modified to explain this and to refer to Standard Wall groups.
iii. SHEARLINE, WALL and OPENING DIMENSIONS Table
The legend has been modified to refer to Standard Wall groups.
iv. DEFLECTION Table
The legend has been modified to refer to Standard Wall groups.
3. Highlight of Failing
Walls (Feature 75)
If a wall failed
design for the design case (wind shear, wind C&C, seismic, rigid diaphragm,
or flexible diaphragm) shown on the screen, then the failing wall appears in
red. The colour for a selected wall, which used to be red, is now orange. If a
failing wall is selected, it appears as a darker shade of red.
A note at the bottom
of the screen indicates that orange is for selected walls and red for failing
walls. It also indicates the design case being shown on the screen.
4. Design Summary (Feature 138)
To allow you to
identify walls and hold-downs that fail design without having to scan the full
design results report, the program now includes a design summary. It appears in
the Design Results report before the shear results for the first design case
(just after the loads are output). In addition, the program alerts you with a
pop-up message if any walls fail.
a) Message Box for Wall Failure
If any walls fail
for any design case (rigid diaphragm, flexible diaphragm, wind shear, wind
C&C, seismic), the program shows a message box on the screen that gives the
levels and he design cases that the
failure occurs. It tells you to go to the Design Results or to see the
highlighted walls in Plan View (see Feature 75, above)
For each design
case (wind shear loads - rigid
diaphragm, wind shear loads - flexible diaphragm, components and cladding wind
loads - out-of-plane sheathing, components and cladding wind loads - nail
withdrawal, seismic loads - flexible diaphragm, seismic loads - rigid diaphragm) the design
summary either indicates that there were no under-capacity walls, or gives a
list on each level of the names of the walls that failed.
For each design
case (wind shear loads - rigid
diaphragm, wind shear loads - flexible diaphragm, seismic loads - flexible
diaphragm, seismic loads - rigid diaphragm) the design summary either indicates that
there were no under-capacity hold-downs, or gives a list on each level of the
names of the walls that contained under-capacity hold-downs.
The Go to Table menu that appears when the
Design Results are shown now includes an item for Design Summary.
5. 500mm
Stud Spacing for Unblocked Factor (Feature 173)
The program now
allows input of 500mm (19.2”) stud spacing, corresponding to 1/5th
of the length of a standard sheet of plywood. When 500 mm or 19.2” is selected,
the program uses the unblocked
factor in O86 Table 9.33 for 500 mm.
6. Hold-down Offset Subtraction from Overturning
Moment Arm (Bug 2731, Change 165)
The program did not
subtract the hold-down offset from the moment arm when calculating overturning
hold-down forces, even though O86 9.5.6.1 requires it and that the disabled
checkbox in the Hold-down settings indicates that it is to be subtracted.
Since 9.5.6.1 says you should use the centre of the end stud as your
hold-down offset for moment arm calculations, we now allow you to use the
centre of the end wall stud assembly that you input in Wall Input View for each
wall in the structure. A checkbox in the Hold-down settings is used for this.
The default value is to be checked.
When drawing, the program now draws the tension side hold-down at the
full stud thickness from the wall end, because it depicts the bracket, not the
center of the bolt through the studs.
7. Hold-down Force Accumulation Tolerance (Change
169)
The program now accumulates hold-downs forces from the floor above with
the one on the floor below when these forces are that are offset by as much as
1.5 " in plan. This is the minimum distance from wall end.
8. Non-convergence of Deflection-based
Distribution to Segments (Bug 2770)
Occasionally,
Shearwalls is unable to distribute forces to the shear wall segments by
equalizing the deflection of each segment due to non-convergence of the
numerical routine used.
If this happens, the program now outputs a note below the Shear Design table indicating the affected shearlines.
b) Inconsistency of Deflection and Design Forces
In such a case, the force on the segment used for shear wall design could be markedly different than the force used for deflection analysis. This has been corrected, and they are now the same. However, it should be noted that these forces do not result in equal deflections on the shearlines, and the value selected is just one in the succession of non-converging iterations that can oscillate between very different values. We recommend turning to capacity-based rigidities for load distribution if this occurs.
9. Uplift Loads on Walls with Openings (Bug 2744)
When uplift loads
were added to a wall with openings, the elevation view displays incorrect
values superimposed on top of one another. Each opening added to the wall
caused an additional increase in the incorrectness of the uplift load
magnitude. The incorrect uplift load magnitude was used to calculate hold-down
forces, which were shown in Plan View, Elevation View, and the Hold-down Design
table.
10. Verification of Stable Design in Final Design
Check Iteration (Bug 2743)
The program was doing
a full load distribution and wall design during the final design check
loop. The design check loop was intended
to use the previous iteration's load distribution and designed walls to verify
that the wall design / distribution achieved a stable design. By doing a full
load distribution and wall design on the last iteration the verification check
was not identifying when the wall design / load distribution does not achieve a
stable design, and not issuing the appropriate warning. This has been
corrected.
11. Design for Distribution of Forces to Shear Wall
Segments Based on Rigidity
The following
problems occurred when the Distribute
forces to wall segments based on rigidity and the Use shearwall deflection to calculate rigidity Design Settings were
both selected. They have been corrected:
a)
Selection of
Critical Segment in Design for Unknowns (Bug 2730)
The program did not take into account the distribution of forces on individual shear wall segments between openings when determining the critical segment for design. Instead it considered only the lowest Jhd value from all segments on the wall. As a result, walls with "unknown" material or hold-down choices sometimes failed design when the program should have designed a stronger wall that would pass.
b)
Design Ratio and
Failure Warnings for Segmented Walls (Bug 2884)
When forces are distributed to individual segments via deflection, in the design loop the program evaluates the wall via the force vs. capacity of the critical segment. However, in the design report, it shows only the force vs. capacity for the entire wall, that is, the sum of the forces vs. the sum of capacities, as per O96 9.5.1. Therefore walls that fail design and can be passed over in the design loop can pass when each parameter is selected by the user.
This has been corrected by showing the design ratios in the output for each segment on the wall, and failure warnings for if any one of them is under capacity.
12. Output Warnings for Inadequate Stud Thickness
for Hold-downs (Bug 2825)
If you selected a
hold-down that is not rated for the thickness of wall studs at the end of the
wall, then the program did not design for that hold-down and it used the
displacement over-ride entered in the settings. It issued a warning in the
hold-down design and hold-down displacement tables to that effect.
Since the wall studs
do not necessarily include “cripple” or “jack” studs beneath the window that
can contribute to hold-down strength, the program now issues a warning to the
effect that extra cripples or jack studs are needed, and continues with
hold-down design using the capacity and displacement for the least thick stud
assembly that the hold-down is rated for.
The warning is no longer in red indicating a failed design.
13. Hold-down Stud Width for Capacity and
Elongation (Bug 2826)
If there are multiple
entries for hold-down capacity for different stud widths, and the entries are
listed with the larger stud width before the smaller width and the wall’s stud
width is greater than both entries, the program used the capacity and elongation
for the smaller stud width even if the larger width was the closer match. This
has been corrected.
14. Levels and Directions for Out-of-Plane and Weak
Storey Seismic Irregularities (Bug 2824)
Shearwalls sometimes
reported the wrong building level or direction for which a Type 5 irregularity
(Out-of-Plane) occurred. This irregularity could also be incorrectly allowed or
disallowed due to the Weak Storey (Type 6) irregularity as it was using the
wrong level or direction. These problems have been corrected.
15. NBCC Terminology (Change 164)
All references in the
program to NBCC, meaning National Building Code to the correct acronym for the
building code, NBC.
B: Building Model and Program Operation
1. Design and Load Distribution Processing Time
The time taken to
design shear walls and to distribute and draw loads and forces has been
markedly improved, by a factor of at least twenty, so that delays that used to
occur in the operation of the program have been reduced to manageable levels.
a) Slow Processing Time when Designing Complicated
Structures (Bug 1837)
When a project had a combination of many shearlines, many exterior surfaces, many blocks, and multiple stories, the time taken to analyze and design the structure could be very slow, sometimes as much as 30-60 minutes. Such a structure now takes 1-2 minutes. Smaller, less complicated structures also design much faster, so that a building that used to take a few minutes to design now designs in a matter of seconds.
b) Slowdown in Updating the Drawing of Loads (Bug 2750)
Once loads had been generated, every time you went into Load Generation action or Loads and Forces action, the drawing of
the building and loads in plan view would
hang for many seconds, especially for complex buildings with a large number of
loads. This also happened while you
scrolled the view, selected walls, moved the window, edited loads, etc.
This has been corrected and the drawing of the loads has been accelerated by a factor ranging from a small amount to up to several thousand times, depending on the complexity of the building. The delay in drawing loads is now a fraction of a second and manageable.
2. Multiple Extend Upwards (Feature 193)
The program allows
you to extend your walls upwards in stages, that is, extend walls up through a
more limited number of levels than to the top of the building. However, in
order to maintain a closed envelope, you must always extend the walls through
at least one level and cannot build a level from scratch.
For example, for a
five storey structure, you can make a floor plan, extend to floor 2, then be on
floor 3, make a floor plan, extend only to floor 3 (that is, not at all), then
make another floor plan, and extend it from level 4 to 5. Unlike the current operation, the level
indicator in the data bar is active during this process to allow you to do
this.
Two inputs, one to show the level that you are on and one to show the level that you are copying it up to, that is the range of levels. The levels are called Current level and Extend to. The Current Level input is always disabled and is there to show you the range. Once the process is complete, it becomes enabled to select levels and Extend to disappears.
If you choose an intermediate storey, or don’t extend at all by selecting the same storey, then press extend, the program then
-
extends to
the level selected,
-
creates a
new floor plan from the blocks for the next unextended level,
-
sets the
current level to the next unextended level,
-
sets the
in Extend to to the highest level,
-
outputs a
prompt explaining how to proceed.
If you extend to a level that is one below the highest level, the program in fact extends to the highest level and copies the next-to-highest level to that level.
The Undo and Redo commands are active during this process and allow you to go back and try again if you have made a mistake.
3. Accept Design (Feature 153)
The other WoodWorks
programs, Connections and Sizer, allow you to transfer the design results from
a successful design back to the input fields, replacing unknown values on those
fields. This allows you to experiment with and tweak your design, for example
to use fewer different types of materials at the expense of optimal strength in
some areas.
This ability has now
been added to the Shearwalls– you can transfer the design results for all walls
in the structure from one of the four design cases – combinations of Rigid or
Flexible Diaphragm, and Wind or Seismic.
A sub-menu now appears in the Action menu called Accept Design. When dropped down, it gives the choice of the four design cases for which to accept design.
If one of the Design Cases is selected in the Accept Design Menu, loads from that design case is shown on the screen. However, this is not reciprocal, if you select another design case via the Show menu, the Accept Design case does not change. In this way, you can always check the design case that was used to accept the design.
The Accept Design command is invoked either from the Accept Design submenu, or via a button at the far right of the main program toolbar.
When you rerun design after Accepting design, the program may fail for other design cases than the one accepted, because the unknown values have been replaced by ones strong enough for that design case but not for others. If that is the case, you can reset some parameters to unknown, then re-run design and then select the critical case for “Accept Design”. After a few iterations of this procedure, you can achieve a design that satisfies all design cases.
Non-shearwalls are updated only if they were designed for C&C wind loading.
4. Log File in Viewer (Feature 208)
The log file which
provides load generation and rigid diaphragm analysis details has now been
integrated into the program and appears in a window within the program
framework. Previously the program invoked the Notepad program to show the log
file results. The window is called Load Generation and Torsional Analysis
Details. The menu and status bar descriptors have also been updated.
5. Log File Button (Change 120)
A button has been
added to the main program tool bar to invoke the log file, and to toggle the
log file viewer on and off. The log file button has been removed from the
toolbars attached to the windows for Plan, Results, and Elevation views.
6. Getting Started Steps (Change 122)
The Getting Started dialog has been updated
to reflect the current state of the program. The text shown for Roofs and Generate Loads has been changed and a new step, Step 14, Log File Output, has been added.
7. Crash after
Moving Opening then Entering One (Bug 2856)
Occasionally, after
moving openings on upper-level storeys, then creating a new opening on the same
wall, the program would crash. This has been corrected.
8. Creation of Perpendicular Non-shearwalls (Bug
2880)
After one segment of
an exterior non-shearwall is perpendicular to the wall to create two
perpendicular joining segments, those segments are designated shearwalls rather
than non-shearwalls. They otherwise had the same materials as the
non-shearwalls. This has been corrected and they remain non-shearwalls.
9. Location of Standard Walls File for Network
Installations (Bug 2776)
For network
installations, the file that stores the standard walls was previously located
on each local client machine. The standard walls file is now located on the
network server in the same location as the materials and hold-down databases. This was needed now that the standard wall
groups are used for design grouping.
1. List of Cities for Default Seismic and Wind
Data (Feature 209)
The list of cities
shown in the Default Settings from which you select the location for your wind
speed q and seismic parameters Sa (T = 0.2, 0.5, 1.0, 2.0) has been expanded,
Previously it included a list of 80 major centers across Canada. Now it includes
all the municipalities listed in Appendix C of NBCC, a total of 670 cities.
A dropdown list of
all provinces and territories has been added to the program, and you first
select your province and a list of cities in that province appears, with the
capital city appearing by default. You then pick the city closest to your
design location.
Shearwalls project
files from previous versions will use the city closest to the one in the old
list, for example Kitchener-Waterloo will now be Kitchener and Chicoutimi is
now Saguenay. The new list of cities also contains the proper spelling of
cities in terms of including accents and hyphens.
The following
improvements have been made to the treatment of Component and Cladding loads
and C&C design.
a) C&C Loads Per Wall Line (Feature 206)
Because different wall lines can have different reference heights h because they are on different blocks, but be on the same face of the building in terms of N, S, E, W directions, the program now assigns separate C&C loads to each wall line. If the wall line includes walls from more than one block, the highest C&C load from the blocks is used.
As a result, C&C loads are shown in plan view on each wall line with exterior walls. Previously only one C&C load was shown for each building face.
b) Windward Pressure (Feature 207)
Previously the program used the worst case of the outward (suction) C&C pressure for both sheathing strength and nail withdrawal design, although it is possible for the combination of windward external pressures and negative internal pressure to be greater than leeward internal pressures and positive internal pressure. This caused somewhat conservative design for nail withdrawal, which is applicable only when exterior forces are outward.
Furthermore, some users were confused by the discrepancy between their calculations for windward pressures and the C&C pressures on the screen for a windward load direction shown.
Accordingly, Shearwalls now calculates the windward and leeward pressures separately and uses the leeward for nail withdrawal design.
i. Plan View
Shearwalls now shows the windward pressure if the displayed wind direction is directed towards a surface, e.g. for the west face for west to east loads. It previously showed the leeward (suction) pressure.
ii. Elevation View
Both the leeward and windward pressures are now shown in elevation view.
iii. Design
The worst of leeward and windward pressures are used for sheathing design. Only leeward pressures are used for nail withdrawal.
c)
Reference Height
for Ce (Bug 2500)
The reference height used for calculation of windward velocity pressure coefficient Ce is now the actual height at the top the level in question, rather than the eave height of the structure. This applies to both external and internal pressures. As the Ce factor at the 20m level is 0.82, and the minimum Ce is .70, the C&C loads can be conservative by as much as 17% on the lower levels, however, since the C&C load on lower levels does not tend to govern because of the accumulated shear forces on lower levels, this change has little effect for most designs.
3. Leeward I-!5 Method Reference Height for Ce (Bug 2810)
Starting with version
8.11, the program was using the eave
height of the building as the reference height for h for calculating leeward Ce
for the I-15 method, however, Commentary I- 7 (b) says to use 1/2 the building
height. This is a conservative bug effecting taller structures, as the minimum
value of 0.7 for rough terrain and 0.9 for open terrain is imposed for shorter
structures. The bug affects buildings taller than 12.5 meters for rough terrain
and buildings greater than 6 metres for open terrain.
For a 20-meter
building, for rough terrain the program was using a .82 Ce when it
should be 0.7, for a 17% conservative error, and for open terrain, it is using
1.15 when it should be 1.00, for a 15% error. This has been corrected.
4. Crash on Load Generation for Closely Spaced
Walls (Bug 2687)
The program sometimes
crashed during seismic load generation when walls are positioned such that they
could belong to more than one shearline.
5. Crash when Generating Loads on Merged Walls
(Bug 2882)
Starting with version
8.3, if walls are segmented then merged again, the program crashes when
generating loads. This has been corrected.
6. Torsional Irregularity for Wall Lines with Zero
FHS (Bug 2738)
When determining the
deflections on extreme shearlines to derive the Bx from NBC 4.1.8.11 (9) for
Irregularity 7 – Torsional Sensitivity, the program was failing to identify
those exterior wall lines that do not have full height sheathing, so are not in
fact shearlines. It was assigning zero storey drift at the building edge in
those cases, which also caused the program to be more likely than it should
assign a high Bx.
Now, if the outermost
wall lines do not have full height sheathing, the program uses the next closest
shearline with full height sheathing, which may in fact consist of interior
walls.
7. Message for Applicability of I-15 Method for
Multi-block Structures (Bug 2738)
The message about
applicability of I-15 method for multi-block structures no longer has the
comment about the Cp factors on the block the wall was originally
part of, which was rendered obsolete by the fix to Bug 2473 in version 8.2,
below.
8. No Species Group in Initialization File (Change
2738)
If the installation
does not have a current initialization file for the materials database
(database.ini), so that the species group is not identified, the program now
uses a stud density of 0.42 corresponding to S-P-F for anchorage deflection
calculations. Previously the program would crash. This problem would not
ordinarily be encountered by regular users of the program and was a problem
primarily for internal testing.
D: Drawings and Graphical Input
1. Import of Bitmap and PDF Versions of CAD Files
(Feature 126)
Previously, the
program allowed input only of Windows Metafile (.wmf) or Enhanced Metafile
(.emf) file formats for CAD drawings to use as a template to draw your
structure. Now, the program allows you to input bitmap (bmp) and portable
document format (pdf) files. The program converts the pdf to a bitmap before
drawing it.
The CAD Import Wizard for importing of the CAD drawings has been updated to allow the following file types:
Metafiles (*.wmf, *.emf)
Bitmaps (*.bmp)
PDF (*.pdf)
The operation of the program is the same for bitmap files and pdf files converted to bitmaps as it is for the metafiles the program was previously restricted to.
2. Adding Openings over CAD Import (Feature 150)
As it was difficult
to see openings on imported CAD drawings as the solid shear walls in plan view
obscured them, the drawing for the openings action when CAD drawing is showing
has been modified to allow you to see openings. Segmented shear walls are
transparent with diagonal lines. Perforated walls have hatches and the
non-shearwall is blank as before. If there is no CAD import showing, then shear
walls are shown in solid colour as before.
3. Graphical Selection of Openings (Feature 23)
Previously, and
opening could only be selected via a drop list in the Opening Input form. Now
in the Openings action of Plan View, if you select anywhere within
the thickness of the wall over the extent of any of the openings, then the
opening selected is the one available for editing in the input form.
4. Display of Wall Group Name (Feature 102)*
The program now
allows you to display the name of the standard wall used for each wall in both
Plan view, which is now also the wall design group. This is controlled by a
checkbox in the Display group of the Options setting. It defaults to being
checked. If all walls on a shearline have the same materials, the name is shown
only once.
5. Slowdown in Updating the Drawing of Loads (Bug
2750)
Once loads had been
generated, every time you went into Load Generation action or Loads and Forces
action, the drawing of the building and loads in plan view would hang for many
seconds, especially for complex buildings with a large number of loads. This
also happened while you scrolled the view, selected walls, moved the window,
edited loads, etc.
This has been
corrected and the drawing of the loads has been accelerated by a factor ranging
from a small amount to up to several thousand times, depending on the
complexity of the building. The delay in drawing loads is now a fraction of a
second and manageable.
6. Appearance of Load Arrows (Bug 1952)
For large structures,
the arrows in Plan view representing
applied loads became much more widely spaced than for smaller structures, and
the arrowhead was not visible. This has been corrected and the appearance of
the load arrows is similar for large and small structures.
7. Color of Text in Load Generation Legend (Bug
2815)
The Unfactored generated shear load and Vertical elements required items in the
legend that appears on load generation are now coloured blue like the rest of
the legend, not orange.
8. Plan View Update
Quality (Change 161)
The plan view now
draws more smoothly without flashing on changes or when scrolling.
1. Standard Wall Copy (Feature 178)
Previously, to create
a copy of a Standard Wall was done in a roundabout way that not all users were
aware of. (by pressing Add, then
selecting from a list of Standard walls).
To make it more evident, we added a Copy
button to allow you to copy an existing Standard wall. You must make at least
one change to this standard wall before it can be saved.
The old way of
copying a Standard wall still exists alongside the new one for those users who
are more comfortable with it.
2. Default Load Type
when Adding Loads (Feature 141)
The program used to
revert to the Dead load type each
time you added a new load. Now it uses the type of whatever load is selected in
Wall Input View, which is the last
load previously added. This allows you to enter multiple loads of the same type
without resetting the load type on each one.
Note that the very
first load you enter will now default to the type of the first generated load
in the list, instead of Dead. If
there are no generated loads, then Wind
shear will be the type of the first load entered.
3. Creating Standard Walls with Unknowns (Bug 2887)
Sometimes when trying
to save a new standard wall with some parameters set as "unknown",
the program would not allow it, presenting a message box saying that all fields
had not been filled in. This happened frequently for OSB materials and occasionally
for other materials, and has been corrected.
4. Default Thickness for OSB Sheathing. (Bug 2805)
The program defaulted
to a particular panel marking when OSB was selected, rather than to Unknown as it does for other inputs, and
to a particular thickness when a panel marking is selected, without even
allowing for Unknown thickness. This has been corrected and when OSB is
selected, the panel marking and thickness default to Unknown.
5. Unknown OSB Interior Panel Markings (Bug 2881)
It had been possible
to select "Unknown” as the Panel
marking for OSB for interior wall side. Unknowns are not supposed to be in
the interior wall selections because the program does not design for unknowns
on the interior side unless both sides are the same.
Selecting
"unknown" resulted in a zero shear deflection for that wall to be
zero. Shear deflection is ordinarily only a small component of deflection, so
the impact of selecting unknown was often negligible.
6. Conversion of Imperial Units for Wall Framing
Thickness (Bug 2804)
For imperial units, a
value typed into the Framing "Width d" is interpreted by the program
as being a metric value and immediately converted to imperial by dividing the
value by 25.4. This incorrect value was then used for design. This has been
corrected.
7. Tool Tips for Wind Load Generation Controls
(Bug 2675)
When you hovered your
mouse over the input controls of the Wind
Loads group of the generate loads box, small “tool tip” messages appeared,
but they did not appear for the seismic loads controls or other buttons in the
dialog box. In addition, the Exclude roof portions checkbox mistakenly gave the message for C&C loads.
Messages have been
added for all inputs in this box and the Exclude
roof portions message has been
corrected.
8. Input of Invalid Wall Location (Bug 2754)
Changing the location
of a wall via the input field in the Wall Input dialog of a wall to a location
that was invalid because it is outside the building perimeter, intersects with
another wall, etc., caused the program to crash. The program now shows an error
message and does not allow the wall to be made.
9. Add Load to Selected Wall (Change 254)
If no wall was
selected and Selected wall was chosen
in the Apply to... combo box when
adding a new load, a large value automatically appeared in the From X= and To X= fields. Furthermore, you are allowed to enter a load which
appeared on a random building face.
The program has been
changed to revert to the previous Apply
to... selection in this case.
10. Editable Ply and Panel Marking Input Box (Bug
2807)
Starting with version
8, the field that is used for Plywood plies and for OSB Panel marking is editable,
when it should be a non-editable selection list Typing data into this box did
not cause a problem; the program simply ignored it and used the default for the
designed thickness.
11. Enabling of Double-Bracket Boxes in Openings
View (Bug 2813)
In openings view, if
no wall is selected, all inputs were greyed out except for the two
double-bracket checkboxes at the bottom. With no wall selected, or with a wall
with no openings selected, clicking on one of these the double bracket
checkboxes caused a crash. These controls are now disabled when no walls are
selected, and will not cause a problem when clicked.
12. Wall Framing and Hold-down Behaviour on
Multiple Selection (Bug 2816)
When multiple walls
with varying properties are selected, none of the fields on the Framing or
Hold-down sections of Wall Input View were set be blank to signify an
indeterminate selection. This does not currently happen for any field in the Framing or Hold-down sections in Wall
Input View, instead showing the value of the most recently selected wall.
This is purely a display issue; the actual properties of each wall are
correctly maintained.
13. User Interface Rearrangement
The input fields in
throughout the user interface have been rearranged somewhat for better
alignment, to ensure that all data selections are completely visible in all
boxes, that dropdown lists drop down to reveal all choices without scrolling,
correct minor typos, etc.
In the Wall Input
View, the position of Thickness and Plies inputs have been reversed to better
reflect the interdependency of these inputs.
14. Design Code Clause Number in Design Settings
for Collector Force Method for Irregularities (Change 151)
The reference to the
design code clause 4.1.8.15(6) in the Design Settings about the applicability
of capacity-based collector forces for irregularities has been changed to the correct
4.1.8.15.(4). This was due to a renumbering for NBC 2010 vs 2005.
15. Save as Default for
New Files (Change 255)
The following settings were not being saved as
defaults when Save as default for new
files was selected.
-
Line 4 of
company information under Company Information
-
Worst-case
rigid vs. flexible diaphragms in Design Settings
This has been corrected.
16. Moisture Conditions
Input on Design Code Change (Change 256)
When the Design Code changed from CSA O86-09 to
CSA O86-14, and vice versa, the nomenclature for the moisture conditions was
not being updated until you selected OK
and then opened the design settings again. This has been corrected.
17. Default Setting for Save as Default (Change
159)
The default setting
for Save as default for new files for Default Values and
Company Information settings has been changed from being unchecked by default
to being checked by default.
18. Reset Original Settings (Change 257)
a) Moisture Conditions
Fabrication and In-Service Moisture in Design Settings were not being reset to their original value after you reset original settings.
b) Display Gridlines
The input for gridline interval next to Display gridlines in the Plan View settings Elevation View settings remained disabled if Display gridlines was not checked before you reset original settings.
c) Snap Increments
The Snap Increments input in Plan View and Elevation View settings was not being re-enabled if the Display gridlines was not checked before you reset original settings. It is now enabled after the reset because Display gridlines is checked in that case.
d) Imperial Formatting
If you selected imperial units and then resets to original settings, the unit system changed back to Metric, but the Distance, Thickness and Force combo boxes remained enabled. They are now disabled when the unit system is Metric.
19. Fastener Length and Diameter Input for Power-driven Nails (Change 258)
-
For
power-driven nails, an error message would appear indicating the fastener
length is too small when the fastener length field lost focus and you had
selected unknown fastener length. This message is no longer displayed under
this circumstance.
-
When
fastener diameter loses focus and the user has selected unknown diameter, the
diameter would automatically be set to 0. This issue has now been fixed.
-
The progam
allowed input of a zero fastener diameter but would design as if it was
unknown. Now if you enter a fastener diameter of 0, the Diameter input automatically changes to Unknown.
20. Minimum Nail Diameter for Power-driven Nails (Changes 260 and 261)
The software placed a
minimum requirement on the diameter of power-driven nails to be 2.84 mm when
deflection analysis is enabled and 2.0 mm otherwise, and showed. The diameter
of power-driven nails must now be greater than or equal to 2.0 mm regardless of
whether deflection analysis is enabled.
Furthermore, the
message saying Nails less than
[2.0", 51mm] in length … has
changed to Nails less than 2.0" in
length …
21. Asterisk Next to Framing Thickness and Width
(Change 262)
In the Wall Input dialog, the Thickness and Width of wall studs can be entered by the user as well as selected
from a list in the wall input dialog, but did not have an asterisk next to them
like the other editable fields. The asterisk has been added.
22. Wall Dead Load Input (Change 153)
The input for creating special wall dead loads for Jhd calculations was in the wind section of the Load Generation dialog, when it applies
to both wind and seismic. This has been corrected.
23. Project Files with Hold-downs Deleted from
Database (Bug 2827)
When loading a
project file that contains hold-downs that don’t exist in the current hold-down
database, the missing hold-downs were added to the database, but the Cap S-P-F
field is populated with a nonsensical value. This has been corrected.
24. Message for No Species Group in Database.ini
File (Change 167)
If you do not have a
current database.ini file so that the species group is not identified, an error
now appears on the screen and a stud density of 0.42 corresponding to S-P-F is
used for anchorage deflection calculations. Previously the program would show
nonsensical hold-down design, which also affected deflection calculations.
Please note that if
this situation occurs, the program repeats the message many times. If you
continue to dismiss the message, the design will eventually complete normally.
This will be corrected for the next version of the Shearwalls. The situation that an incorrect database.ini
file is on the computer ordinarily exists only in internal testing
environments.
1. Shear Results Output for Shearlines which
Extend over Part of Structure (Bug 2822)
The program output
only one line of shear results data when there is only one shear wall on the
line, on the assumption that the information for the line will be identical to
that for the wall. However, when the shearline did not extend the whole
distance between exterior walls, the shearline length is different than the
wall length. The V/L value shown in the shear results output was that for the
shearline, that is, the diaphragm shear flow, and not the design shear flow
that is needed for the wall. The design ratio therefore did not correspond to
the force V/L and the resistance Vr/L values shown in the line.
This was a display
issue only, not affecting design, and has been corrected.
2. Cumulative Storey Shear in Seismic info Table (Change
137)
The value of storey shear for All
levels has been removed from the Seismic Info table. Below the table, the
following lines now appear
Storey shear – Sum of factored, vertically accumulated shearline forces on level,
including torsional effects.
Total unfactored base shear – [value]
3. Shear Line, Wall and Opening Dimensions Table
Legend (Change 162)
The Shear Line, Wall and Opening Dimensions
table legend has been updated to make it more readable and fix minor typos.
Each item now appears on a separate line, similar to other legends. Improved
explanations are given for wall groups and wall length.
4. Component and Cladding Design Table (Bug 2885)
The following
corrections have been made to the Components and Cladding design tables that
show out-of-plane sheathing and nail withdrawal design:
a) Interior Walls on Same Line as Exterior Walls
When a shearline
goes from the interior to the exterior of the structure, the program output a
line of design results for walls that are on the interior of the structure and
are not loaded. Those lines would show zero nail withdrawal force but non-zero
sheathing force. These lines have been removed.
b)
Duplicate Entries
for the Same Wall Group
The program
output a line of data for each shear wall in a line, however showed results by
wall group rather than by individual walls. Therefore there were duplicate
lines when more than one wall on a line had the same wall design group. This
has been corrected and the program shows only one line for each design group on
a shearline.
5. Output of Bx for Torsional
Irregularity (Change 154)
If there is a
torsional irregularity (No 7), the program now outputs the Bx value that caused the irregularity, as
defined in 4.1.8.11(9). It appears in a note under the Seismic Information
table.
6. Design Code Clause in Irregularities Table
(Change 152)
The notes to the irregularities table had the following mistakes, which
have been corrected: 4.1.8.15-6 was changed to 4.1.8.15-4 ; 4.1.8.15-2 changed to 4.1.8.15-5, and 4.1.8.15-2 changed
to 4.1.8-7.
7. Code reference for Gust Effect Factors in Log
File (Change 166)
The NBC reference for
gust effect factors Cg and Cgi have been corrected from
4.1.7.6 a) , 4.1.7.6 b) and 4.1.7.6 c) to
4.1.7.1.(6)(a), 4.1.7.1.(6)(b), and 4.1.7.1.(6)(c).
8. Panel Marking in Sheathing Materials Output
(Bug 2808)
The panel marking in
the notes to the Sheathing materials table was repeated for each wall that has
that panel marking. It is now output
just once.
9. Log File for Torsional Analysis Changes
(Changes 138-141)
The following
problems with the Torsional Analysis section of the log file have been
corrected:
-
The
program output information at the head of the torsional analysis section of the
log file about flexible analysis even if it was not done because there are no
seismic loads.
-
Flexible
seismic design was still performed when it is not possible to do torsional
analysis because of lack of shear walls.
-
The
explanation about Flexible Seismic appeared of context at the top of the file
log file section on torsional analysis, not on every floor as it should.
-
The note
for accidental eccentricity appeared for seismic even though it is about wind.
-
The line
for wind loads showed the building dimension perp to force and says that the
accidental eccentricity is 10D when there was no eccentricity.
10. Shear Design Table Legend (Change 172)
In the legend to the
shear design table, the design code reference for O86 section 9.4.5.2 has been
changed to Figure 9.4.5.2, the description of Fv/V has been clarified,
and the reference to 9.5.1(a) has been moved from Shearlines to Walls.
11. Default Design Results View (Change 155)
When the Design
Results button is pressed, the default view is now 'Preview" which shows a
full page of design results, rather than "Wide View”, which fills the
horizontal extent of the window, usually zooming in on the top part of the
page.
12. Blank Page in Output (Change 157)
The blank page that
was print out at the end of the Design Results has been removed.
13. Capitalization of Load Case (Change 142)
Changed e.g Low-rise case A to Low-rise Case A.
|
|
|
Shearwalls 8.4 – Design Office 8, Service Release 4 – September 13,
2013
1. Update of Inputs Related to Hold-downs (Bug
2683)
When the All shearwalls on shearlines have same
materials setting is selected, making changes to the Hold-down, Double-bracket,
Apply to openings, Number of end studs#, and Hold-down configuration options in wall
input view had no effect. The program merely reverted to the previously
selected value. This has been corrected.
2. Moving Wall Lines with User Applied Forces (Bug 2676)
Starting with version
8 of the program, moving a wall that is on a shearline with a directly applied
shearline force caused the program to crash. This has been corrected.
3. Update of Unknown Nail Spacing Input (Bug 2667)
When Both sides same is selected, the edge
spacing did not include the Unknown
option, and this persisted for both exterior and interior side when the
checkbox was deselected. This has been corrected, and Unknown is again allowed when both sides are the same.
4. Nonsensical Values for Anchorage Deflection (Bug 2677)
Under certain
circumstances, the program reported extremely high negative values for
anchorage deflection in the Hold-down displacement table. These unrealistic
displacements were used in the calculations for deflection, creating
nonsensically high deflections.
This has been
corrected. It happened under the following circumstances:
When the distribution of forces within a line resulted in zero force on a segment, because other stiffer segments draw the entire load.
When there is no uplift force at a location, that is, the counteracting dead load and/or compressive force from above is greater than the overturning force.
Shearwalls 8.31
– Design Office 8 Service Release 3 – March 12, 2013
Please also consult
the entries for version 8.3 below to view all the changes since the last
version released to the public.
1. Uplift Forces Shown in Hold-down Displacement
Table (Bug 2641)
The values shown in
the Hold-down displacement table for uplift force P were mistakenly showing
forces factored for Ultimate Limit States (4.2.4.1), whereas deflection
calculations use serviceability limit states (4.2.4.2). As a result, it was
possible to have a positive load showing in the table, but zero shown as the
elongation, because the serviceability-factored load is negative and not acting
as an uplift load.
This has been
corrected and the forces showing are those factored for serviceability limit
states. Note that the value used for determining the amount of hold-down
deflection is in fact ultimate limit state, because it is compared to the
hold-down capacity for ULS to determine the proportion of maximum elongation.
Otherwise, all, values used for hold-down displacement calculations are SLS.
The ULS values are
shown in the Hold-down design table.
2. Serviceability vs. Ultimate Limit States in
Table Legends (Bug 2641)
The legends to the
following tables for wind design have been changed to make it clear whether
loads and forces are factored for ultimate limit states (ULS), serviceability
limit states, or unfactored, and whether they include an importance factor if
otherwise unfactored:
Wind Shear Loads
Wind Uplift Loads
Wind C&C Loads
Shear Design
Deflection
Hold-down Displacement
3. Directionality of Uplift Wind Loads (Bug 2638)
a)
Blank Input for
Wind Uplift Force Direction
Starting with version 8.1, we allow the wind uplift forces to be entered for each wind direction separately, but by default, when an uplift load was selected, nothing appeared in the wind direction box. If you proceeded to enter the loads without selecting a direction, or both directions, then the wind uplift did not get included in the combined hold-down forces, and the separate wind uplift component of the hold-down force that was shown in elevation view and in the output report was unreliable.
In addition, a load entered with blank direction showed up as blank in the Load Input dialog edit field, E->W in the load list, and Both directions in the load list in the output report. In fact, it acted as none of these.
The default showing in this box is now “Both Ways”, and it is never allowed to be blank.
b)
Display of Uplift
Loads Entered in Both Directions
If a selection was made for the wind direction before adding the load, the combined hold-down forces were correct; however the uplift component appeared in elevation view for both directions, when it shouldn’t have.
Different loads entered west to east and east to west (the usual case) were shown superimposed and thus garbled in plan view and in elevation view, along with the uplift components of the hold-downs.
These problems have been corrected.
The following problems in the Load Input screen used for editing existing loads were corrected:
All loads showed up in the load list as E->W, even if they were W-> E or Both Ways.
An E->W load selected showed the direction in the edit box as blank.
4. Restriction of Shearwall Materials when All
Segments have Hold-downs (Bug 2625)
The program restricts
the nail spacings available for selection to be at least 100 comply with
O86 9.4.5.5 a) when you have indicated in the design settings you want the
program to apply these material restrictions. However, it does so even when you
have indicated in the Hold-down configuration in Wall Input view that
hold-downs are on all segments, so that Jhd cannot be less than one,
as 9.4.5.5 stipulates.
It is likely that the
program applies other restrictions on nail size and sheathing capacity in this
case as well.
It was possible to
get around this problem by changing the design setting so that materials are
not restricted; however this affected all walls, even those that have
anchorages.
This has been
corrected and the program does not apply material restrictions to walls that
have hold-downs on all segments.
5. Apply Load Change Message (Change 119)
After first entering
the Load Input view, changing loads prompted you to apply changes when none had
been made. This has been corrected.
6. Seismic Load Generation Input Typos (Change
121)
The spelling of Self-weights has been corrected from Self Weights. The “Generate building
masses first…" section title has been extended to fit the ellipses.
7. Getting Started Steps (Change 116)
The Getting Started dialog has been updated
to reflect the current state of the program. The text shown for Roofs and Generate Loads has been changed and a new step, Step 14, Log File Output, has been added.
Shearwalls 8.3 –
Design Office 8 Service Release 3 – Feb 27, 2013
This version of
Shearwalls was released to only a limited number of users for use in a training
seminar. The changes listed here are also in the 8.31 version of the program released to the general
public.
The links below lead to descriptions of
the changes.
A: Component and Cladding
(C&C) Design
1. Update to CSA O86-09 for
Sheathing Strengths for C&C Design (Bug 2628)
2. Sheathing Strength Values for
C&C Design
3. C&C Design Table in the
Results Output
1. Interior Zone C&C Loads for the I-15 Method (Bug 2633)
2. Cp and Cg Factors in the Log File
for I-15 Method C&C Design (Bug 2635)
3. Wind Load Generation Log File Legend (Bug 2635)
1. Accumulation of Direct
Shearline Force for Seismic Design (Bug 2630)
2. Distribution Method for
Seismic Direct Shear Forces (Bug 2632)
A: Component and Cladding (C&C) Design
1. Update to CSA O86-09 for Sheathing Strengths
for C&C Design (Bug 2628)
The allowable Component and Cladding (C&C) plywood loads have been updated to new values from the CSA O86 2010 Tables 7.3A-7.3B, from the O86 2001 values that were being used.
The following materials have been added:
- 3-ply 12.5 mm and 6-ply 15.5 mm plywood, for both Doug-fir (DF) and Canadian Softwood Plywood (CSP).
For the following materials, allowable strengths have increased for at least one stud spacing:
- DF: 18.5 mm, 7 ply, 0° (horizontal orientation);
- CSP: 3-ply 7.5 mm and 9.5 mm; 4-ply and 5-ply 12.5 mm°; 5 ply 15.5 mm; 7-ply 18.5 mm; all 0°.
For the following materials, allowable strengths have decreased for at least stud spacing:
- DF: 4-ply 15.5 mm, 0°; 5-ply and 6-ply 18.5 mm, 0 and 90°.
- CSP: 3-ply, 9.5 mm, 90°; 4-ply and 5 ply 15.5 mm, 0°; 5-ply and 6-ply 18.5 mm, 0 and 90°.
Note that CSP 5-ply, 15.5 mm, 0° is in both lists because it decreased for 304.8 stud spacing and increased for 406.4 and 609.6 spacing.
The OSB Type 1 material has been removed, as it is no longer in CSA O86. It had been in table 7.3C
The Construction OSB values, which were in Table 7.3D, did not change for CSA O86 2010 Table 7.3C
2. Sheathing Strength Values for C&C Design
a)
18.5 mm, 7 ply
Doug Fir Plywood (Bug 2629)
In generating the allowable C&C loading on of horizontal Douglas-fir plywood 18.5 mm x 7 plies, a bending strength mp’ value of 100 n/mm/mm was used, instead of the correct 1100 from Table 7.3A, 0° orientation. The bending strength was correspondingly 11 times lower than it should be, and the allowable loads 7-11 times lower depending on stud spacing.
The allowable C&C load for 9.5 mm 2R24 OSB sheathing was 7.4 when it should have been 7.94. This has been corrected.
3. C&C Design Table in the Results Output
a) Nail Withdrawal Design Ratio (Bug 2637)
The design ratio in the Design Results output for nail withdrawal shows the end zone ratio for both end zones and interior zones. It now shows the correct ratios.
This problem did not affect design, as the end zone ratio is used for nail design.
b)
Sheathing
Strength Design Code Reference (Change 132)
In the legend a reference to CSA O86 Tables 7.3A-C was added, with an explanation of the bending and shear criteria used.
c)
Precision of
Imperial Nail Withdrawal Values (Change 130)
The number of digits precision for Imperial nail withdrawal force and capacity has been changed from whole pounds to 10ths of a pound.
d)
Design Code
Reference for Nail Withdrawal Capacity (Change 133)
The design code reference for nail withdrawal capacity was mistakenly showing 10.9.4, when it should be 10.9.5. This has been corrected.
1. Interior Zone C&C Loads for the I-15 Method
(Bug 2633)
Starting with version
8.2 of the program, for the I-15 (all heights) wind load generation method, the
program was generating interior zone Component and Cladding (C&C) loads
using the 1.2 Cp* coefficient from Figure I-8 and end zone loads
with the 0.9 coefficient when it should be reversed. These loads appear in plan view, elevation
view, and the C&C table of the design results.
As a result, the
program designed for nail withdrawal for lighter than expected end zone loads,
but may show a failing design ratio in the output for the heavier than expected
interior zone loads. It conservatively designed for sheathing strength using heavier
than expected interior loads.
2. Cp and Cg Factors in the
Log File for I-15 Method C&C Design (Bug 2635)
a)
Combined vs
Separate Cp and Cg
The Component and
Cladding (C&C) loads for the NBC Commentary I - 15 method in the log file
showed a combined pressure coefficient and gust factor CpCg,
when in fact they are separate factors, similar to the main shear force
resisting system (MWFRS) factors for this method. They are now shown as
separate Cp and Cg factors.
The combined internal
factor CgCpi is also now shown separately as Cgi
and Cpi.
b)
Inclusion of
Internal Factors in External Factors
The factor showing
was the difference between external and internal forces (NBCC 4.1.7.1 3)),
which was contradicted by the legend to the table. It now shows the external
coefficients only (4.1.7.1 1)).
c)
Inclusion of Ce
for Internal Factors
The combined internal
factor mistakenly included the value of exposure factor Ce for
internal pressures, but this has been resolved by splitting the combined factor
up.
3. Wind Load Generation Log File Legend (Bug 2635)
The legend in the log
file which defines the symbols used for wind load generation procedures has
been improved in the following ways:
-
Separate
legends for I-7 and i-15 wind load generation methods (Change 131)
-
Design
code references have been added for all symbols from NBCC and the Commentary.
-
Combined
pressure coefficient and gust factor no longer given for I-15 procedure,
replaced by separate definitions of Cp and Cg factors.
-
Separate
definitions for internal and external factors
-
Explanations
of load Magnitude and Start and End given
-
Separate
table header for C&C load items which differ from MWFRS items. They are no
longer indicated by asterisks and a difficult-to-spot note.
-
Now
indicates that velocity pressure is one in fifty year pressure.
1. Accumulation of Direct Shearline Force for
Seismic Design (Bug 2630)
Starting with
Shearwalls version 8, when a seismic direct shearline force was applied to a shearline,
the program did not include that force in the rigid diaphragm design shear. The
direct forces did show up in both plan view and elevation view, but not
accumulated with forces on the line from the generated loads, so the numbers
overlap. This has been corrected and the seismic direct shearline forces are
once again included in the design shear force.
2. Distribution Method for Seismic Direct Shear
Forces (Bug 2632)
Starting with
version 8.1 the Distribution Method control in the Load Create and Load Edit
dialog boxes was disabled and showing Both
when entering or editing manually entered seismic direct shear forces. This
has been corrected and you can again distinguish between rigid and flexible
distribution methods when adding a direct shearline force.
Shearwalls
8.2 – Design Office 8 Service Release 2 – January 9, 2013
The links below lead to descriptions of
the changes made to WoodWorks Shearwalls for Version 8.2
A: Force Distribution and
Engineering Design
1. Elevated Dead Load Magnitude and Reduced Jhd Factor
(Bug 2565)
2. Non-wall Dead Loads Treated as Wall Dead Loads (Bug 2571)
3. Nail Slip Deflection of Unloaded Gypsum Wallboard (Bug
2577)
4. OSB Shear Defection Values for Deflection Design (Bug
2582)
5. Segment Shear Value in Deflection Table when Both Sides
Same (Bug 2584)
6. Shear Deflection for Custom Sheathing Thicknesses (Bug
2585)
7. Nonsense Hold-down Values at Gable End of Monoslope Roof
(Bug 2509)
8. Crash for Walls Spanning Multiple Blocks at Gable End (Bug
2510)
9. Torsional Sensitivity Seismic Irregularity Detection (Bug 2523)
10. Irregularity Message Typo (Change 128)
1. Base Shear due to Manual
Building Masses on North-South Lines (Bug 2518)
2. External Pressure
Coefficients for Wall Loads (Bug 2595)
3. External Pressure Coefficient
for Leeward Roofs (Bug 2596)
4. MWF Wind Loads All-heights
Coefficients in Log File (Bug 2501)
5. All-heights Co-efficients for
Walls Extending Between Blocks (Bug 2473)
1. Standard Wall Relative
Rigidity (Bug 2522)
2. Bolt Diameter Input in
Hold-down Database for Decimal Imperial Formatting (Bug 2517)
3. Hold-down Database Message
(Change 116)
4. Apply Load Change Message
(Change 119)
5. Seismic Load Generation Input
Typos (Change 121)
6. Arrange Icons Menu Item
(Change 129)
1. Wind Load Importance Factor
for Deflection (Bug 2576)
2. Log file for Wind Generation
(Changes 115,124.142)
3. Log File output of Area Load
Magnitude (Bug 2483)
4. Precision of Design Shear
Values in Shear Results Output (Bug 2495)
5. ASD Typo in Hold-down
Displacement Table (Change 118)
6. Bending Term in Deflection
Table Legend (Change 127)
1. Failure to Open a Project File (Bug 2088)
2. Back-up Files (Change 123, Feature 203)
A: Force Distribution and Engineering Design
1. Elevated Dead Load Magnitude and Reduced Jhd
Factor (Bug 2565)
Starting with version
8.11, dead loads over openings did not accumulate properly, creating two sets
of overlapping loads in load view over openings, with a load used for hold-down
creation and Jhd calculation that is much too large. Therefore, there is too heavy a countervailing
dead force at hold-down locations, and the Jhd factors that are calculated via
9.4.5.2,3 are significantly too small, as Jhd is directly related to
hold-down force P. Both of these are non-conservative errors, and have been
corrected.
2. Non-wall Dead Loads Treated as Wall Dead Loads
(Bug 2571)
Entering a dead wall
load caused subsequently entered dead loads to be treated as dead wall loads,
even if the checkbox for wall dead loads is not checked. As a result, the
uplift restraining force P in 9.4.5.3 for hold-down factor Jhd did
not include these loads, resulting in a smaller than expected P and larger than
expected Jhd, a non-conservative error. This equation is used
wherever an anchorage exists above a hold-down. This
problem has been corrected.
3. Nail Slip Deflection of Unloaded Gypsum
Wallboard (Bug 2577)
When the constant
nail slip deflection for gypsum wallboard (GWB) is so much greater than the
deflection for the wood side that it draws no load, the program was still
assigning the constant nail slip deflection to GWB. As a result, the deflection
of the shearline was much greater than it should be, and it’s stiffness is much
less, causing it to draw less loading under rigid diaphragm distribution or
when loads are distributed to dissimilar materials along a shearline. This
happened most often under low loading conditions, and has been corrected.
4. OSB Shear Defection Values for Deflection
Design (Bug 2582)
For the OSB
construction sheathing thicknesses other than the smallest for each panel
marking, the program used zero for shear deflection rather than the actual
shear deflection. The program now gives the correct shear deflection in this
case.
5. Segment Shear Value in Deflection Table when
Both Sides Same (Bug 2584)
When there is the
same sheathing on both sides of the shear wall, the v value reported in the
deflection table is the shear going into just one of the sides, so it is in
fact ˝ the total shear applied to the segment.
The resulting deflections calculated are correct; however the program
was showing a misleading shear value. The program now shows the total shear
going into the segment in this case.
6. Shear Deflection for Custom Sheathing
Thicknesses (Bug 2585)
If you type in a
sheathing thickness rather than a standard one, the shear deflection was set to
zero. This has been corrected and the program now uses the deflection for the
next smallest sheathing.
7. Nonsense Hold-down Values at Gable End of
Monoslope Roof (Bug 2509)
When there is a
monoslope roof, the hold-down calculations at the gable end yielded nonsense
values indicative of a divide-by-zero situation. These hold-down forces
appeared in all output and were used in the design of hold-downs at these
locations. This has been corrected.
8. Crash for Walls Spanning Multiple Blocks at
Gable End (Bug 2510)
When all the
following criteria are met
-
A wall is
directly under a gable end
-
The wall
spans more than 1 block
-
The last
block in the block list doesn't have any sides that are collinear with the wall
The program crashed
when performing load and force distribution. This occurred regardless of
whether there are actually any loads on the structure. This sometimes happened when loading a file and the program proceeds to
the load view stage.
9. Torsional Sensitivity Seismic Irregularity
Detection (Bug 2523)
The torsional
sensitivity irregularity for rigid seismic design (NBCC 2010 Table 4.1.8.6
Irregularity Type 7), was not being detected when it should have been. The
program was mistakenly comparing the deflections due to positive and negative
torsion for each outer edge shearline.
It should have been comparing the deflections of the opposite outer edge
shearlines, and is now doing so.
The incorrect
calculations would rarely result in a torsional irregularity being detected.
10. Irregularity Message Typo (Change 128)
The message that appears when seismic
irregularities 4-6 are detected has been corrected to refer to APEGBC instead of APERGBC.
1. Base Shear due to Manual Building Masses on
North-South Lines (Bug 2518)
When a building mass
is manually added to a North-south shearline, the seismic load from the
resulting mass did not contribute to base shear on the structure, creating
lower-than-expected forces distributed to the building levels. However, the seismic load from the building
mass is created, using the base shear computed without the contribution of that
load. Furthermore, when any seismic load is entered manually, it is not
included in the base shear to be distributed to the rest of the building. This
is not incorrect, but has been made more evident to the user via a note beneath
the seismic information table and in the log file.
2. External Pressure Coefficients for Wall Loads
(Bug 2595)
Starting with version
8.11 of the program, instead of the expressions for external pressure
coefficient, Cp, based on
height to depth ratio from NBCC 2010 Figure I-15 , the program always
used the value of 0.27 in the range 0.25
< H/D < 1.0, resulting in loading that was less than half of what it
should be. This has been corrected and the program uses 0.27( H/D + 2.0) for
windward walls and -0.27( H/D + 0.88) for leeward walls.
Note that for
buildings in these ranges are ordinarily designed using the low-rise method,
I-7, but Shearwalls does not use this method for multi-block structures, and it
is likely not be used for flat roofs, so this problem is likely to have
occurred for these types of structures.
3. External Pressure Coefficient for Leeward Roofs
(Bug 2596)
Because NBCC Figure
I-15 is only applicable to flat-roofed buildings, a decision was made to apply
the external pressure coefficients for walls, Cp, to the vertical
projection of roof panels. However, the coefficient applied to leeward roofs
was not following the wall coefficient calculation based on height to depth
ratio. Instead it was using the worst case leeward wall coefficient, -0.5,
resulting in heavier-than expected loading for h/d ratios less than 1. This has been corrected and the program is
applying the coefficients 0.27( H/D) for 0.25 < H/D < 1.0 and 0.3 for h/d
< .25. Note that for buildings in
these ranges are ordinarily designed using the low-rise method, I-7, but
Shearwalls does not use this method for multi-block structures, and it is
likely not be used for flat roofs, so this problem is likely to have occurred
for these types of structures.
11. Low Rise Wind Loads Due to Note 8 for Positive CpCg
Coefficients (Bug 2550)* corrected for Canadian references and terminology
Low-rise wind loads
due to Note 8 of Structural Commentary Figure I-7, that specifies zone 3
loads on a portion of a zone 2 windward
roof, were being generated for high angles with positive Zone 2 co-efficient CpCg
when they should be limited to low angles with negative CpCg,.
The resulting zone 3 loads have a negative coefficient that combined with the
loads with a positive zone 2 coefficient to reduce the total load on the roof,
creating non-conservative wind loading. This has been corrected.
4. MWF Wind Loads All-heights Coefficients in Log
File (Bug 2501)
The CpCg
coefficient shown in the log file for main wind force resisting system loads
for the all-heights wind generation was divided by the Ce factor
when it should not have been. This has been corrected.
5. All-heights Co-efficients for Walls Extending
Between Blocks (Bug 2473)
When a building is
made from multiple intersecting blocks, the program creates two walls along one
of the sides of an "L", but only one wall along the side of another.
The two walls are assigned to different blocks for wind load creation, but one
the one wall extending between two blocks and until now was assigned to only
one block for wind load generation. When this occurs, you have no way of
splitting the long wall up and manually assigning different blocks to the
separate walls. This also occurs when you manually joined walls from separate
blocks.
This could create
incorrect wind loads for blocks with radically different height-to-width
ratios, for example, that a wall extends from a one-storey block to high one
with several stories. It has been corrected and the program internally splits
the wall up and assigns the co-efficients from the correct blocks to the walls.
Refer to an
explanation in the Help files, under Canadian wind load procedures, for a
picture and more details.
Note that the version of this document
originally included with Shearwalls 8.2 mistakenly included two changes that
have since been removed: Apply
Load Change Message (Change 119) and Seismic
Load Generation Input Typos (Change 121).
1. Standard Wall Relative Rigidity (Bug 2522)
The "Relative
Rigidity" input for Standard walls was not reflected in the individual
walls’ relative rigidity. The program now considers relative rigidity field
when comparing walls to see if they match standard walls.
2. Bolt Diameter Input in Hold-down Database for
Decimal Imperial Formatting (Bug 2517)
When the Thickness
Imperial formatting setting is set to Decimal, then the list of bolt shaft
diameters in the Hold-down database input shows nonsensical values like
“1/1”. If you select one of these, or
attempt to enter a value like .45, the program converted it to 0, 1, or a
nonsense value the next time the box is opened. This
has been corrected.
3. Hold-down Database Message (Change 116)
The message
indicating that one hold-down had to be completed before another selection had
a grammar error.
4. Apply Load Change Message (Change 119)
After first entering
the Load Input view, changing loads prompted you to apply changes when none had
been made. This has been corrected
5. Seismic Load Generation Input Typos (Change
121)
The spelling of Self-weights has been corrected from Self Weights. The “Generate building
masses first…" section title has been extended to fit the ellipses.
6. Arrange Icons Menu Item (Change 129)
The Arrange Icons menu item was removed from
the Windows menu as it was obsolete
and had no function.
1. Wind Load Importance Factor for Deflection (Bug
2576)
The program now
indicates in the legend to the deflection table that the shearline forces are
multiplied by the ratio of the serviceability to strength importance factors,
or in the case of Normal importance, 0.75. For this case, the shearline force
that appears in the table is a factor of 0.75/1.4 less than the strength force
(1.4 being the wind load factor.) Since the legend did not indicate that it is
factored, some users expected it to be just 1/1.4 times the shearwall design
force.
2. Log file for Wind Generation (Changes 115,124.142)
The output of wind
loads for the log file has been updated as follows:
-
NBCC
references have been added to each equation.
-
The Iw in the Site information has been
expanded to Importance factor: Iw.
-
Spaces
have been added to pressure equations to make them more readable.
-
For Fig
I-15 generation method the following changes have been made:
-
The
columns and legend entries for the low-rise values windward corner, Case A or
B, and slope have been removed;
-
The
combined CgCp column has been separated into individual columns for Cp and Cg,
with corresponding changes to the legend. For C&C loads, the combined CgCp
value is output between the Cg and Cp columns.
3. Log File output of Area Load Magnitude (Bug
2483)
The magnitude of
C&C loads and MWFRS loads created as area loads showed up as zero for
metric output and a very small number like 0.1 for imperial output. They are now shown as they appear on the
screen, with numbers like 0.455 kN/m2 or 24.3 psi.
A line has been added
below the table saying “Magnitudes are area loads for C&C and line loads
for MWFRS loads” or “Magnitudes are area loads”, depending on how the loads
were generated.
4. Precision of Design Shear Values in Shear
Results Output (Bug 2495)
Starting with version
8, the design shear values in pounds per linear foot, Fv/L, appear in the shear
results table as whole numbers. Previously they had 0.1 plf accuracy, which has
been restored.
5. ASD Typo in Hold-down Displacement Table
(Change 118)
In the hold-down
displacement table, it now says ASD, not ADS, when referring to load
combinations
6. Bending Term in Deflection Table Legend (Change
127)
In the legend for to
the deflection table, the numerator to the expression for the bending term
started with a 2 when it should have been a 3. The correct equation was used
for design; this is just an output typo.
Note that the version of this document
originally included with Shearwalls 8.2 mistakenly included the change Getting Started Steps (Change 116) that has since been removed.
1. Failure to Open a Project File (Bug 2088)
Periodically the
program issued an "Unexpected file format" or "WoodWorks has
stopped working message" when opening a project file. When
this occurred the file could not be used and if there was no backup file, then
the project had to be reconstructed. This has
been corrected.
2. Back-up Files (Change 123, Feature 203)
The program now saves
two files to the Windows 7 folder C:\Users\[username]\AppData\Local\WoodWorks\CWC\Canada\8
– BackupPre.wsw and
BackupPost.wsw. The first of these saves a project file immediately before
design or load generation, the second saves the file after design or load
generation.
These files are
accessed in the following situations:
-
if an unsaved file is lost after a successful
design or load generation is made, for example by an automatic system reboot.
Either file can be used for this.
-
The file
BackupPre is used to record the state of the program before design/generation,
so that if a fatal error occurs during one of these processes, you will have a
file to send WoodWorks technical support for diagnosis. In most cases, this
file cannot be used to continue work, as the error will likely occur again on
the next design.
-
The file
BackupPost is used to continue work if an error occurs during design or load
generation, or at any other time. It will return you the state you were in when
the last successful design or generation occurred. Then you can try to remake
the changes you made to your structure, and it is possible the error will not
re-occur. If it does, contact Woodworks Technical support and they will try to
diagnose the problem and find a work-around.
The folder that these
files are saved to in Windows XP is C:\Documents and Settings\[username]\Local
Settings\Application Data\WoodWorks\CWC\Canada\8\.
Shearwalls 8.11 – Design
Office 8 Service Release 1 – May 22, 2012
Some of the
changes listed below first appeared in Shearwalls
8.1, which was released
as an Educational version only. These changes are indicated by Version 8.1 in the next to the change
reference. The links below lead to descriptions of the
changes.
1. Crash on Design with
Non-shearwalls (Bug 2395 – Version 8.1)
2. Wall Height at Gable Ends for
Hold-down Force Calculation (Bug 2465)
3. Creation of Wall Groups due
to Hold-down Data (Bug 2323)
4. Negative Jhd Factor for
Hold-downs on All Walls (Bug 2445)
5. Inclusion of Gypsum Capacity
for Tall Walls (Bug 2447)
6. Extraneous Message when
Running a Design (Bug 2439)
7. Irregularity Check Warning
(Change 110 – Version 8.1)
1. Wind Uplift Load
Directionality (Feature 115)
2. Building Mass Generation for
Separate Floors (Bug 2386 – Version 8.1)
3. Low Rise Wind Generation for Multiple Blocks that are
Deleted (Bug 2430)
4. All-heights Wind
Load Coefficients
5. Structure Height-to-width Ratio
6. Multi-block All-heights Warning Message (Change 113)
7. Precision of Velocity Pressure q in Log File (Change 114)
8. Log File output
of Area Load Magnitude (Bug 2484)
C: Data Input and Program
Operation
3. Legend Checkbox in Options
Settings (Bug 2398– Version 8.1)
4. Hold-down Settings
Dimensional Units (Bug 2468)
5. Spin Controls for Building
Levels in Generate Loads Input View (Bug 2387 - Version 8.1)
6. Deflection Analysis Setting
Update (Bug 2327)
7. Version Number in Program
Name (Change 111)
8. Streamline Network Version
Setup (Design Office Feature 8)
1. Interior Non-shearwall
Material Information in Elevation View (Bug 2352)
2. Floor Joist Length in
Elevation View (Bug 2383)
3. Overlapping Hold-down Forces
at Vertical Elements in Elevation View (Bug 2389)
4. Overlap of Structure and
Legend/Materials In Elevation View (Bug 2405– Version 8.1)
5. Wall Name in Shearline, Wall
and Opening Dimension Table (Bug 2420)
1. Crash on Design with Non-shearwalls (Bug 2395 –
Version 8.1)
In some cases, the
program crashed when designing a structure that has a non-shearwall and
deflection design is enabled. This has been corrected.
2. Wall Height at Gable Ends for Hold-down Force
Calculation (Bug 2465)
In order to include
the portion of an end wall that is beneath a gable end as part of a shearwall, for
the purpose of hold-down force calculations, the program now calculates the
wall height at a gable end as being the distance from the base of the wall to
the height of the sloping roof at the end of a wall segment.
The average of the
heights at both ends of the segment under a gable end is used as the moment arm
h in the hold-down force calculation R = vh, where R is the hold-down force and
v is the shear per unit foot directed horizontally. Previously the height of
the upper level was used as the wall height. Refer to the Shearwalls Help topic
Hold-down Forces for further
explanation.
3. Creation of Wall Groups due to Hold-down Data
(Bug 2323)
The program created
wall design groups based on hold-down information such as "number of
brackets”, hold-down type, and number of end studs. It no longer does so for
the following reasons:
-
The Sheathing and Framing Materials output
does not show these values, so there was no evident difference between wall
groups.
-
These
parameters do not affect design of the wall, just deflection
-
These
parameters differ from other wall group parameters in that they can be
different for different walls on the line when “dissimilar materials” are not
allowed. Therefore a line would have two groups designed for it, and only one
of these was used for design.
-
The default hold-down configuration is to have
single bracket on first level and double on others, so by default wall 2 wall
groups were made even if all materials are the same.
4. Negative Jhd Factor for Hold-downs on All Walls
(Bug 2445)
For a particular
project, two walls on one level were not designed, so that the program showed
vertical elements rather than wall ends at the hold-down locations, the
hold-downs were not designed, and a spurious message regarding a negative Jhd
appeared. Upon examination, this problem
was caused by incorrect conversion of joist spacing when toggling between
metric and imperial modes. This has been corrected.
5. Inclusion of Gypsum Capacity for Tall Walls
(Bug 2447)
When using imperial
units, if the height of a wall was greater than > 3.6 m with gypsum
sheathing, the capacity of the wall was not zero as it should be according to
CSA O86 Table 9.5.4 note 2. When using metric units, the capacity was zero as
it should be. This has been corrected.
6. Extraneous Message when Running a Design (Bug 2439)
In some rare
instances, when running a design you get an inaccurate message saying that due
to a change in the structure, the last design is no longer valid, and asking
you to design again. If you choose to design again, the design proceeds without
a problem. This problem has been corrected.
7. Irregularity Check Warning (Change 110 –
Version 8.1)
The NBCC reference in
the Type 4 - In-Plane Stiffness irregularity check warning message has been
updated to refer to sentence 4) of 4.1.8.15 instead of sentence 6). This
message is output when the lower storey within a vertical discontinuity has a
lower capacity than the storey above.
Also, the spelling mistake in the word Stiffness has been corrected.
1. Wind Uplift Load Directionality (Feature 115)
The program now
allows you to specify the direction for wind uplift loads, that is, the lateral
direction of wind force with which the uplift load is associated. Therefore you
can enter uplift loads that correspond to the uplift coefficients for the
windward and the leeward surfaces in NBCC Figure I-7 for low rise loads and
Figure I-15 for all heights. Previously the one wind uplift load applied to a
surface would be used for both the windward and the leeward cases. This
involved the following program changes:
The Wind direction input is now enabled and allows you to choose either direction or Both, similar to a Wind shear load.
b) Graphics
In the Plan View and Elevation View, the wind uplift force is only drawn if the direction of the uplift force matches the direction of load direction selected in the Show menu.
Different uplift forces are used to create combined hold-downs at the same location for different force directions. These appear in the Hold-down Design table.
A Direction column was added to the Uplift Loads table,
2. Building Mass Generation for Separate Floors
(Bug 2386 – Version 8.1)
When self-weights
were entered in stages for several levels of the structure, and building masses
and loads generated at each stage, the loads due to the lower portion of the
wall mass from the storey above were not included in the calculation if the
loads were generated from top to bottom. Similarly, the loads due to the upper
portion of the wall mass from the storey below were not included twice in the
calculation if the loads were generated from bottom to top.
Furthermore, the
calculation of total building mass used only the masses from floors that had
already been generated, leading to a different result than if the loads had
been generated all at once.
These problems lead
to significantly non-conservative loading when the loads are generated in
stages, particularly when it is done from top to bottom of the structure.
They have been
corrected and the program now generates the correct seismic loads when building
masses are generated in stages. Note that the seismic loads that are generated
for a particular level after the entire structure is complete will be different
than those at an intermediate stage, because of the difference in total
building mass. The loads generated at
the intermediate stages should not be used for design.
3. Low Rise Wind Generation for Multiple Blocks
that are Deleted (Bug 2430)
When walls were
created using multiple blocks, then all but one of the roof blocks are deleted,
the program considered it a single block building when deciding whether
low-rise wind loads were allowed. The program used the walls created from only
one of the original constituent blocks to determine the height to width ratio,
and disallowed buildings that should be allowed. If the one block used had an
allowable h/w ratio, then the program generated wind loads on only the walls on
that block, and not on the rest of the building. Now, if multiple blocks are
used to create the walls, wind loads cannot be generated for low-rise load
design, and you are alerted with a message.
4. All-heights Wind Load
Coefficients
The following changes
apply to the implementation of the NBCC Structural Commentary Figure I-15
method for “high-rise” structures, that Shearwalls uses on all structures for
which the low-rise method is not permissible.
a)
All-heights
Pressure Coefficients Cp for H/D < 1
(Bug 2469)
The program now applies the wall pressure co-efficients Cp given in Figure I-15 when the height-to-depth ratio is less than 1.0. Previously it was using the maximum values, that is, those for H/D > 1 regardless of the dimensions of the building. This created conservative loading by as much as 33% for windward walls and 66% for leeward walls. The “D” used is the depth of the building block that the wall or roof panel was part of when the walls or roofs were originally created. The H used is the eave height for walls and the ridge height for roofs.
Refer to 5b) below, for the depth used for irregular structures.
b)
Interior Zone Local
C&C Coefficients (Bug 2480)
The program now implements the local coefficients +- 0.9 for component and cladding (C&C) loads on windward surfaces. These coefficients apply to sheathing and nailing design, as they are intended for components roughly the size of a window according to Commentary I-29. Previously the program was using the coefficient -1.0, from the 1995 NBCC.
c)
End Zone Local
C&C Coefficient (Bug 2480)
The program now implements the local coefficients -1.2 for C&C loads on the end zones of windward surfaces. These coefficients apply to nailing design, as they are suction forces. Previously the program was not using separate end zone wind pressures for nail withdrawal, or showing them in the plan or elevation view.
d)
CpCg
Value for C&C Loads in Log File (Bug 2480)
The combined pressure and gust CpCg coefficient shown in the log file for all-heights C&C loads for the all-heights method did not correspond to the Cp coefficient multiplied by the Cg factor; instead included the Ce factor as well. This has been corrected.
e)
Ce Value for
C&C Loads in Log File (Bug 2480)
The exposure factor Ce in the log file for all-heights C&C loads was always shown as 1.0. The correct factor now appears.
5. Structure Height-to-width Ratio
a)
Building Width
for Low-rise Restriction (Change 112, Bug 2466)
When determining the height-to-width ratio of the structure for use in the low-rise load restriction in NBCC Structural Commentary I-26, that is, height/ width < 1, the smallest of the two plan dimensions of the storey with the largest such dimension is now used as the width. Previously the smallest plan dimension of the smallest storey was used, leading to situations whereby this ratio might be determined by a small penthouse. Judgement must now be exercised in using this method for a structure that has an extensive one-storey base with a narrow multi-storey tower above.
b)
Building Depth
for All-heights Cp (Change 112, Bug 2466)
In determining H/D for Commentary Figure 1-15, the program uses the storey with the largest plan dimension. Note 1 to Figure 1-15 says to use the dimension of the building at the base, which in almost all cases will be the largest storey.
c)
Application of All-heights
Restriction (Bug 2432)
When generating wind loads using NBCC Commentaries I-15 all-heights design procedure, if the structure has a height-to-width ratio greater than 4, the wind loads were generated even though NBCC 4.1.7.2 states that dynamic analysis is needed, so that the methods currently in Shearwalls are not applicable. (Dynamic analysis was not implemented due to the rarity of such buildings that also adhere to height restrictions for wooden buildings.) Now, an error message is displayed, and the wind loads are not generated for height to width rations greater than 4.
d)
Building Width
for All-heights Restriction (Bug 2466)
When determining the height-to-width ratio of structures with unevenly sized storeys for the purposes of the I-15 all heights restriction, the program now uses the procedure given in 4.1.7.(3), that is, w = ∑hi wi / ∑hi , where hi = height above grade to level i; and wi = width at height hi .
e)
All-heights vs.
Low Rise Building Width
Note that the building width definition in 4.1.7.2 (3) when considering the applicability of dynamic analysis to all buildings is not used for low-rise height-to-width ratios because the NBCC Structural commentaries in Figure 1-1 assign two separate symbols to these dimensions, w, and Ds, respectively, and they have different descriptors – the minimum building width in each wind direction, and the smallest plan dimension in each direction.
6. Multi-block All-heights Warning Message (Change
113)
A warning message has
been added for the case that the NBCC Commentaries I-15 all-heights design
procedure is used with multi-block structures, explaining that the program is
for buildings with rectangular plan.
7. Precision of Velocity Pressure q in Log File
(Change 114)
In the log file, the
precision of the velocity pressure (q) output in kPa units has been increased
from 1 to 3 digits. Velocity pressures
are published to two digits precision, so the program was rounding the input precision.
Three digits accommodates users who interpolate between locations.
8. Log File output of
Area Load Magnitude (Bug 2484)
The magnitude of
C&C loads and MWFRS loads created as area loads appeared in the log file as
zero for metric output and a very small number like 0.1 for imperial
output. They are now shown as they appear on the screen, with numbers
like 0.455 kN/m2 or 24.3 psi. A line has been added in the output
saying “Magnitudes are area loads for
C&C and line loads for MWFRS loads” or “Magnitudes are area loads”, depending on how the loads were
generated.
C: Data Input and Program Operation
The following
problems with the operation of the Standard Wall input were introduced with
Version 8 of the program, unless otherwise noted:
a) Saving Newly Added Standard Walls (Bug 2365–
Version 8.1)
When adding a new Standard Wall you could not save
the new standard wall unless you had selected an existing standard wall as the
basis for the new wall. If you had selected a standard wall as a basis, the
material, species and grade fields are not initialized and must be edited in
the Edit Standard Walls view before exiting the view. If this is not done you
would lose any standard walls that you had created in any session and
Shearwalls reverts to using the original set of standard walls.
These problems have corrected.
b) Non-blank Fields when Adding New Standard Wall
(Bug 2367– Version 8.1)
Originally, when creating a new standard wall,
the program would blank out all material input fields, forcing the user to
choose each one in turn. After choosing one, it would only trigger the
selection of another one if there was only one choice for that input.
This functionality became successively degraded
with each release, and an increasing number of fields became either non-blank
from the start, or become selected when another controlling field is selected.
Other fields, however, remain blank, creating an inconsistent look and
behaviour.
All fields now remain blank, if there is more than
one choice, until you select each of them in turn.
c)
Standard Wall
Identification (Bug 2418)
In Wall Input view, the program did not always identify walls that are created identically to an existing standard wall as being that standard wall, because of inaccuracies concerning the stud thickness and depth. For example, this would occur when the width or depth were changed, then changed back to those for the original standard wall. This has been corrected.
d)
Standard Wall
Default Setting (Feature 139)
Because the default standard wall selected in the Default Settings applies only to the walls created from the blocks when first entering Wall Input view, the name of the Standard Wall data group box has been changed to Standard wall for exterior footprint. A note has been placed in the box explaining that new interior walls depend on what is selected in Wall Input view.
The following
problems with the new inputs for stud thickness and width in Wall Input view were corrected:
a)
Conversion of
Custom Stud Width and Thickness (Bug 2410)
When you entered your own width or thickness (rather than selecting a value) this number was divided by 25.4 before being used in design, and the smaller value appeared when you entered the view again. This resulted in very large deflections due to bending, and correspondingly low wall stiffnesses. It could also skew the distribution of loads to shearlines and within a line in a way that could be conservative or non-conservative for shear wall design. The unit conversion causing this problem has been corrected.
b)
Stud Thickness
and Depth Unit Label (Bug 2415)
While in Wall Input view, if you changed from imperial units to metric units or visa-versa, then the unit label of the stud thickness and depth were displayed in the original units, not the units switched to. It would remain that way until any other operation was done in this view. The correct units now appear in all circumstances.
3. Legend Checkbox in Options Settings (Bug 2398–
Version 8.1)
The following issues
with the operation of the Display Legend item in the Options Settings have been
corrected.
Control of Material
Specification
Turning this option
off also controlled the sheathing and framing materials as well as the legend
in Elevation View, even though there are separate options the material
specification. Now it controls only the legend.
A legend option has been added to control the display of the legend in Plan View.
b)
Position of
Legend Checkbox
The legend option no longer appears between the similar options sheathing and framing, it appears below them.
4. Hold-down Settings Dimensional Units (Bug 2468)
The values input into the Hold-down Settings box could lose precision when updating after the following operations
-
After
being saved as a default for new files
-
Being converted
between imperial and metric
-
In some
cases, upon re-entering hold-down settings view
-
On the
case of the over-rides, immediately after entering the data
These problems have been corrected, and in general values appear to 1/10 of a millimetre and 1/1000 of an inch, however the program will show even millimetre amounts without the decimal, and will remove all but one trailing zero after the decimal place for inches. If more precise values are entered, they will be retained internally, but will be replaced by the rounded value if view is re-entered and another value is modified.
In metric units, the default bolt hole tolerance would sometimes appear as 0.0625 mm, that is 1/16th of a millimetre. It is meant to be the metric equivalent of 1/16” . This has been corrected.
5. Spin
Controls for Building Levels in Generate Loads Input View (Bug 2387 - Version
8.1)
The spin controls
beside the Building Level inputs in
the Generate Loads input form went
missing, so that you had to type in a value instead of scrolling to it. They
have been restored.
6. Deflection Analysis Setting Update (Bug 2327)
In Design Settings, the default values of
the Shearwalls Rigidity options were
not being reset when the Include
deflection analysis checkbox was reselected. Now, if you choose to do
deflection analysis, Use shearwall
deflection to calculate rigidity and Distribute
forces to wall segments based on rigidity are automatically selected.
7. Version Number in Program Name (Change 111)
Shearwalls now has
the version number in the name of the program that appears in the program title
bar, and over icons that appear in the start menu. This enables you to quickly
identify the version of the program you are running.
8. Streamline Network Version Setup (Design Office
Feature 8)
The procedure to set
up multiple users running the program from a network server has been
streamlined, as follows:
a)
Copying of
Shearwalls.ini file.
Previously, you had to manually copy a version of the Shearwalls.ini file to all the client machines. The program now does this automatically.
It is still necessary to modify the Sizer.ini in the server to indicate it is a network version and give the location of the program on the server. A new step is required, to copy the files from the Program Data area of the server for All Users to the corresponding folder in the Program Files area of the server. In other words, the Shearwalls.ini file on the server will be found in one of the following locations
Windows 7 - C:\ProgramData\WoodWorks\CWC\Canada\8\
Windows XP - C:\Documents and Settings\All
Users\Application Data\WoodWorks\CWC\Canada\8\
After modification, it has to be copied (not only moved) to the following location, if the default installation was selected:
C:\Program Files (x86)\Woodworks\Cdn\Sizer\
The advantage of this approach is that the file has to be copied only once, and within one machine, rather than distributed to several machines.
b)
Modification of
Database.ini File
With the introduction of new locations for database and setting files with Version 8, the network installation required you to modify the file Database.ini by indicating it was a network installation. This is no longer necessary.
c)
Instructions in
“Read Me” File
The instructions in the Shearwalls Read Me file have been modified to explain the new procedure. In addition, the following corrections have been made:
-
The
instructions regarding key code security instruct you to contact WoodWorks
sales, rather than using a key code that is delivered with the software.
-
Instructions
were given for those users who wish to modify the database files on their local
machine using Database Editor on the server. These have been removed, as this
procedure is not possible.
1. Interior Non-shearwall Material Information in
Elevation View (Bug 2352)
For interior
non-shearwalls, or for exterior non-shearwalls for seismic-only design, known
material input was showing up as Unknown
in the elevation view material output. Now, if material input is defined for an
interior or seismic non-shearwall, then it shows up in the material
information. If the inputs are left as
unknown, they appear as unknown as there is no design for interior or seismic
non-shearwalls.
Note that if shearlines are not restricted to All walls the same and there is more
than one non-shearwall on a shearline only the material information for the
southernmost or westernmost non-shearwall is shown.
2. Floor Joist Length in Elevation View (Bug 2383)
In Elevation view, for a multi-storey
structure with an upper storey overhanging the storey below, the floor joist of
the upper storey did not extend below the overhanging upper storey but only to
the end of the storey below. The overhanging portion of the upper storey was
therefore without a floor, and vertical elements supporting it had a gap
between the top of the element and the supported portion of the building.
The program now draws
the floor based on the length of the wall above. Now an end portion of a wall
that has no wall above it will no longer show a floor area above it. Such a
wall may or may not in reality have a floor area; it could support a sloped roof
instead.
This is a display
issue only that has no effect on load distribution or design.
3. Overlapping Hold-down Forces at Vertical
Elements in Elevation View (Bug 2389)
When compression and
tension hold-down forces are distributed downwards by a vertical element, these
forces shown in Elevation view at the
bottom of the element were drawn overlapping each other. Furthermore, the
arrowhead for compression hold-down force in these locations was often drawn
within the joist depth rather than outside it as it is usually drawn. This
problem has been corrected and the compression and tension forces are shown on
either side of the bottom of the vertical element, with a compression arrow of
the correct size.
4. Overlap of Structure and Legend/Materials In
Elevation View (Bug 2405– Version 8.1)
In Elevation view, lower portions of the
wall elevations often overlapped with the legend and materials specification.
These problems were more noticeable in Selected
Walls mode, and for deep joist depths on the first level being drawn. This
has been corrected.
5. Wall Name in Shearline, Wall and Opening
Dimension Table (Bug 2420)
In the Shearline, Wall and Opening Dimension
table, the wall name had a extraneous, trailing number indicating the building
level, for example if there are two walls on a shearline on the first floor
they are named A-2-1 and A-1-1. The extra "-1" on the end was
removed.
Shearwalls 8.1 –
Design Office 8 Service Release 1, Educational Version – February 3, 2012
This version of
Shearwalls was released as an Educational version only. The changes made for
this version are listed in the later Shearwalls
8.11 release, with Version 8.1 indicated in the change name
line.
Shearwalls 8.0 –
Design Office 8 - November 14, 2011
This is a major
upgrade to the software, containing several extensive new features and many
small improvements. The most significant new features are
Update to the NBCC 2010 Design
Code and CSA 086-09 Standard
Database of Hold-down Connections and Hold-down Design
Shearwall
Deflection Analysis for Storey
Drift and Stiffness-based
Load Distribution
Iterative Load
Distribution and Design of Shearwalls
Here is an index to all
the changes to the program. Click on any of the items to go to the description
of the feature or change.
A: Update to CSA 086-09 from CSA 086-01
4. Hold-downs in High Seismic Zones
5. Seismic Drag Strut Force Factor
6. Unblocked Shearwall Limitations
B: Update to NBCC 2010 from
NBCC 2005
1. National Building Code of Canada
2. Torsional Sensitivity Irregularity
3. Accidental Torsion for Flexible Diaphragms ( Feature 125)
1. Hold-down Types and Properties
3. Shear Distribution to Wall Segments Within Shearline
E: Shearwall Design Iterations
2. Structural Iteration for Irregularities
3. Design Iterations Per Level
F: Other Engineering Design
Issues
1. Shear Strength of Unblocked
Shearwall (Bug 2250)
2. Gypsum Wall Board for Wet Service
Conditions (Bug 2251)
3. Segment Output in Seismic Shear
Results Table (Bug 2275)
4. Gypsum Wallboard Storey Capacity
for One Directional Loading (Bug 2273)
5. Percent Gypsum Shear for
Asymmetric Wind Loads (Bug 2264)
G: Load Distribution and
Accumulation
1. Bi-Directional Seismic Rigid Diaphragm Analysis (Bug
2282)
2. Wind Uplift Loads over Openings (Bug 2132)
3. Shearlines with Zero Capacity and
Non-zero Shear Force (Bug 2211)
4. Full Height Sheathing Output for
Excluded Gypsum Walls (Bug 2355)
5. Accidental Eccentricity Reference
in Log File for Medium Rise Wind Loads
(Bug 2295)
6. Low-rise Wind Load Rigid Diaphragm
Cases in Log File (Change 91)
1. Maximum Seismic Base Shear Vmax in Log File
Output. (Bug 2054)
2. Input of T Greater than Maximum
(Bugs 2281, 2130)
3. Vertical Location of Upper Wall Load (Bug 2107)
4. Area Load Tributary Width and Magnitude Reporting (Bug
2108)
J: Installation and System
Issues
1. Program Data File Locations (Bug 2265)
A: Update to CSA 086-09 from CSA 086-01
The program has been
updated for the CSA 086-09 Engineering
design in wood design standard. The previous version was based on CSA
086-01.
The 086-09
implemented is the 2010 reprint that includes Update No. 1.
These changes are reflected in the program
Welcome box, the Building Codes box, and the About Shearwalls box.
The program now
implements the new shear wall deflection requirements given in 9.7. The details
are given in D: below, Deflection
Analysis, with relevant changes also in C: Hold-down
Connections .
Note that several of the following changes
depend on the seismic load generation value IEFaSa(0.2).
IE, Fa , and Sa are defined in NBCC
4.1.8.5(1), 4.1.8.11(6), and 4.1.8.4(1), respectively. It is shown above the
Seismic Irregularities table.
The program checks
the over-capacity coefficient from CSA O86 9.8.3.1 for structures three or more
storeys in height and when IEFaSa(0.2) is
greater than or equal to greater than 0.35, as per 9.8.1.
The shear capacity
and over-capacity ratio of each floor has been added to the Seismic Information
table for each floor and direction. The storey shear shown is now the
vertically accumulated shear used for shear wall design rather than the single
storey shear distributed to each floor during seismic load generation. (The
single storey shear can still be found in the log file under seismic load
generation.)
The ratio of
overcapacity for level 2 to level 1 is shown at the bottom of the table. A note below indicates that it is within the
acceptable range of 0.9 and 1.2, a warning is issued if it is outside that
range.
*This description modified in March, 2013.
4. Hold-downs in High Seismic Zones
When IEFaSa(0.2)
is greater than or equal to greater than 0.35, as per 9.8.1, seismic hold-down forces based on applied
loads are increased 20% as per 9.8.2. The legend under the Hold-down Design
table has been revised to reflect this.
This factor is not applied if shear wall capacity is used to create hold-down forces, rather than applied loads. However if 1.2 x applied load is greater than shearline capacity, that value is used and a note below the Hold-down design table indicates this.
The legend in Elevation view shows the 1.2 factor and 9.8.2 reference when it is applied.
9. Seismic Drag Strut Force Factor
Seismic drag strut
forces based on applied loads are increased 20% as per 9.8.6. Note that this is not contingent on the value of IEFaSa(0.2),
as per 9.8.7.3. The legend under the Drag Strut Forces table has been revised
to reflect this.
This factor is not applied if shear wall capacity is used to create drag strut forces, rather than applied loads. However if 1.2 x applied load is greater than shearline capacity, that value is used and a note below the Drag Strut Forces table indicates this.
The legend in Elevation view shows the 1.2 factor and 9.8.6 reference.
10. Unblocked Shear Wall Limitations
The maximum height of an unblocked shear wall has increased from 2.44m to 4.88m, as per the change in 9.4.4.
The maximum height-to-width ratio for unblocked shear wall has been reduced to 2:1 from 3.5:1, as per the new limitation in 9.4.4. An item has been added to the Design Settings output echo to show the ratios for blocked and unblocked shear walls (despite the fact that this has been removed from the design settings choices, see Program Operation change 104 below.)
c)
Unblocked
Vertical Sheathing
When the vertical orientation of sheathing is selected, blocking was disabled and unchecked, but the program treated the wall as blocked because of the assumption that the edges of a 4x8 sheet are supported on the studs and bottom and the top plate. Given the new height requirements, the program now allows you to specify whether vertical sheathing is blocked or unblocked.
The Importance factor
for earthquake loads, used in seismic load generation, was changed in 4.2.3.2
from 1.0 to 0.8. However, Shearwalls 7.22 had been using the 0.8 importance factor,
based on NBCC 2005 4.1.8.5, so change to the program was made.
As the CSA O86 no
longer lists OSB Type 1 Sheathing, it has been removed as an input choice. If a file is opened from a previous version
that contains OSB Type 1, then the material type of this wall is changed to
construction OSB and the grades A, B or C are changed to 2R24, 1R24_2F16 and
2R32_2F16 respectively. If the thickness specified is outside of the range of
the valid thicknesses for that marking type then the thickness is set to the
smallest thickness for that marking type.
B: Update to NBCC 2010 from NBCC 2005
1. National Building Code of Canada
The program has been
updated for the 2010 National Building Code of Canada (NBCC). The previous version was based on NBCC
2005.
This change is reflected in the program Welcome
box, the Building Codes box, and the About Shearwalls box.
2. Torsional Sensitivity Irregularity
The program now detects torsional sensitivity irregularity 7 from Table 4.1.8.6, by determining the ration B in. 4.1.8.11(9). Note that this is not a new design code clause, but implementation was made possible by the deflection analysis added to the program.
a)
Torsional Analysis Changes
Previously, for each extreme shearline Shearwalls determined only torsional component for the direction of accidental eccentricity that augmented the direct force on that line. Now the program determines the torsional forces and resulting deflections for each combination of extreme shearline and moment direction, + or -, to determine the δmax values needed.
b)
Rigid Diaphragm
Analysis Procedure
The program checks whether the rigid diaphragm analysis procedure is allowed according to 4.1.8.11 (10) by checking that the maximum B of all Bx on each level as defined in 4.1.8.11(9) is less than or equal to 1.7, or that IEFaSa(0.2) is less than 0.35.
c)
Torsional Irregularity Table
The program now indicates within the table whether each floor and direction has Irregularity 7, and which ones fail because it has the irregularity and IEFaSa(0.2) is greater than 0.35. If it does fail, a note appears below the table saying that rigid diaphragm design results are not valid.
If you have chosen to disable deflection analysis in the Design Settings, then this check is not performed. The Irregularities table indicates it is detected by the user, not the program, puts n/a in the Irregular and Fails columns, and places a note below the table explaining the reason and what can be done about it.
3. Accidental Torsion for Flexible Diaphragms (Feature 125)
The program now
implements NBCC Structural Commentary J 178, which says.
Structures with flexible diaphragms are
designed so that their loads, including the effects of accidental torsion, are
distributed to the vertical elements using the tributary area concept.
Accidental torsion should be taken into account by moving the center of mass by
+/- 0.05Dnx and using the largest seismic loads for the design of
each vertical element.
Note that the 2010
Wood Design Manual (WDM) Example 1, Seismic Design Considerations (p470) includes
this force by adding 5% to the total shearline force.
Noting that to direct
(non-torsional) component of the shearline force should be that determined by
tributary area distribution, this can be achieved by setting the rigidities K
to the flexible shearline force, seeing that
Fdi =
F * Ki / Σ Ki,
using the notation in
the Log file, F being the total force. In that case, the center if mass CM =
centre of rigidity CR, and we are including just the accidental eccentricity ea and not
the eccentricity of the structure or loads. We also do not consider the
torsional moment J in the other direction, as none of the loads are in the
other direction. The torsional component on each line is then
Fti =
T * Ki * di / (Jx)
where di
is the distance of the shearline from the centre of load and
Jx
= Σ Ki * di 2 ; T = F *
ea
Shearlines already
heavily loaded get higher contributions of accidental torsion, rather than
those that are stiffer as in the case of rigid analysis. With seismic analysis,
the distribution of load is proportional to the distribution of the mass of
building material, which itself is proportional to the “area” that the NBCC
commentary is referring to. So with this method, the torsional component is distributed
using the tributary area concept as the NBCC mandates.
b)
Verification of
Calculation Procedure
To show that a simple
case of uniform load on a rectangular building is consistent with the WDM
example, consider a 20 m wide building with 1 kN/m force the diaphragm.
F = 20 kN; Fd1 = Fd2
= 10 kN; K1 = K2 = 10 kN; ea = 1
m; di = 10 m; T = 20 kN-m; J = 2000 kN-m2
Ft1 = Ft2 =
20 kN-m x 10 kN x 10m / 2000 kN-m2 = 1kN
= 5% F
The title of the
entire section of the log file for torsional analysis has been changed from “RIGID
DIAPHRAGM ANALYSIS” to “TORSIONAL ANALYSIS” , in recognition that some of the
output now pertains to flexible analysis. A section is added at the top of the
results called, FLEXIBLE SEISMIC DESIGN. The assumptions given in section a), above,
are shown first, then the results are given as they are for rigid diaphragm
analysis. The source of the accidental eccentricity is given as NBCC Structural
Commentary J 178.
Previously, NBCC
4.1.8.11 (b) for minimum seismic base shear V was the base shear based on S(T =
2.0), and applied to all structures. Now, the requirement for walls is shear walls
is 4.1.8.11 (a), the minimum shear based on S(T = 4.0). As the program has no
input for S(T = 4.0), and elsewhere in the program, we assume periods are not
greater than T= 0.5 based on the height of the structure, we have dropped the
minimum base shear as not applying to wood structures. You could conceivably
enter a large enough period that the minimum is achieved, but that would not
represent a realistic structure.
1. Hold-down Types and Properties
The hold-downs in
shear walls connect the wall end studs on an upper level to either the
corresponding stud on a lower level or anchored to the foundation. Continuous
tie rod systems extending over multiple building levels are not included in
this version of Shearwalls.
i. Vertical Connection
Hold-downs include either an anchor bolt or threaded rod which connects upper and lower brackets or straps, or a continuous strap extending from upper to lower level.
ii. Horizontal Fasteners
The connection from bracket or strap to the upper and lower studs is made via bolts or nails, however this distinction is not implemented in the program as an overall capacity and displacement is specified for each hold-down, and the strengths and slippages of the components of the hold-down not needed.
iii. Single or double bracket
Hold-downs are designated as being either single-bracket or double bracket, indicating that the hold-down has a bracket or strap on one floor or both. By default, hold-downs on the ground level are single-bracket, and upper-level hold-downs are double-bracket. The data in the hold-down database are published for one bracket only and are doubled when the hold-down is designated as double bracket in the Shearwalls program.
iv. Shrinkage Compensating Device
You can designate that the hold-down includes a mechanical device to adjust for the shrinkage of the perpendicular-to-grain wood between the extreme hold-down fasteners, so that such shrinkage is not included in the calculations for shear wall deflection.
b) Displacement and Capacity Sources
There are three possible sources of vertical
hold-down displacement that affects shear wall deflection:
-
anchor
bolt elongation,
-
bracket or
strap elongation,
-
slippage
of horizontal bolts or nails.
Similarly, the
capacity of the hold-down takes into account the possible failure in tension of
the bracket or strap, the anchor bolt in tension, and the connection of the
horizontal fasteners to the wood studs.
The published data are
assumed to include all of these sources, except that displacement values include
the elongation of the anchor bolt to a maximum length. Elongation of the
portion of the anchor bolt greater than that length is analysed separately.
c) Method of Determining Displacement
Hold-downs are
designated according to the method we use for determining the vertical
displacement under loading, as follows.
i. Displacement at Actual Force
With this method, ratio of the capacity of the hold-down to the maximum capacity is multiplied displacement to give the displacement used for deflection analysis and storey drift. This assumption of linear may not be correct, due to the non-linear effects of fastener slippage. This would yield non-conservative results for storey drift determination. However, the choice also affects load distribution to and within shearlines using stiffness analysis, for which the effect may be conservative or non-conservative.
ii. Displacement at Maximum Capacity
With this method, the published displacement at maximum capacity is used regardless of the shear wall force. This ensures conservative storey drift calculations. This choice also affects load distribution to and within shearlines using to stiffness analysis, for which the effect may be conservative or non-conservative.
The program includes
a database of standard hold-downs, which you can edit using a database editor
incorporated in Shearwalls to update hold-down properties or add new hold-downs
The Database folder of the WoodWorks
installation contains a file called Holddowns.mdb,
which is a Microsoft Access database
of hold-downs used by the Shearwalls program. Shearwalls now includes an editor to modify the database, but it is
also possible to modify the file directly via Microsoft Access.
The database consists
of two tables, a Hold-down table that contains the properties of the hold-down
that are relevant to Shearwalls design, and a Displacement table which contains
hold-down capacities and displacements corresponding to each combination of
minimum stud width and depth. The record in the displacement table contains a
reference ID to the hold-down that uses that displacement record.
i. Hold-down Table
The hold-down table contains the following data:
- Name
- Whether it includes an anchor bolt
- Anchor bolt diameter
- The maximum anchor bolt length for which the published elongation applies
- Whether for this hold-down, we use displacement at maximum capacity for deflection analysis
- Whether the hold-down includes a shrinkage compensation device
- Whether the hold-down is to be used as the default hold-down for new projects in Shearwalls
The meaning of these variables is described more fully in the section on Database Input.
ii. Displacement Table
The hold-down displacement table is needed for hold-downs for which the entire assembly displacement is published. For those hold-downs for which only the bracket or strap elongation is published, then only one displacement record is needed, corresponding to the elongation of the bracket or strap. The displacement of anchor bolt and horizontal fasteners is calculated separately by Shearwalls using the information in the Hold-down table.
The file in the
Shearwalls installation contains a limited number of hold-downs, from the Simpsons
Strong-Tie ICC acceptance criteria AC155.
i. Screw mounted Hold-downs
The hold-downs in the initial database that are connected to the upper and lower studs via screws, from the ICC acceptance criteria AC155, are HDU2-SDS2.5, HDU4-SDS2.5, HDU5-SDS2.5, HDU8-SDS2.5, HDU11-SDS2.5, and HDU14-SDS2.5.
ii. Nailed and Bolted Hold-downs
There are no hold-downs in the initial database that are fastened with nails or bolts to the wall studs, however it is possible to add this type of hold-down to the database.
iii. Strap Hold-downs
There are no hold-downs in the initial database consisting of one continuous strap without an anchor bolt; however it is possible to add this type of hold-down to the database.
d)
Single vs Double
Bracket Hold-downs
The displacement data
in the hold-down database applies to just one bracket or strap of a hold-down.
In the program, hold-downs designated as double-bracket have the displacement
values doubled, and the maximum anchor bolt length is also doubled. The capacity data applies to each bracket of
the hold-down, and is never doubled.
When creating a
hold-down with a continuous strap, you can either
-
enter
hold-down data that apply to the elongation of the entire strap and the total
number of fasteners, top and bottom, and designate it as single-bracket in
Shearwalls
-
enter
hold-down data that apply to the elongation of ˝ the strap, and designate it as
double-bracket in Shearwalls.
The program includes
an editor to view and modify the hold-down data. This editor should be used to
update hold-downs for newly published product information from the hold-down
manufacturer. It can be also used to add new hold-downs.
The database editor
is accessed from the following locations:
-
An item in
the main menu
-
A button
in the Plan View and Design Results window’s toolbars
-
A button
in the Hold-down data group in Wall Input and Opening Input views
Each of the input
controls within the database editor has context-sensitive help, explaining its
purpose and use. If you click on the question mark in the upper left hand
corner of the view, then on the input control a small yellow box appears with
the description of the item.
The following are
brief descriptions of the input fields within the box; for more details, use
the context-sensitive help in the program.
c) Hold-down Selection Controls
The Hold-down selector, New and Delete buttons,
and Default… checkbox are used to
control the current hold-down being edited.
i. Hold-down Selector
The hold-down selection dropdown is used to both select the hold-down for viewing and editing properties, to name a new hold-down, or to rename the hold-down by typing over the existing name. It sorts the hold-downs from the database alphabetically.
ii. New
Changes the input mode to refer a new hold-down being created rather than an existing one being edited.
iii. Delete
Used to delete the currently selected hold-down from the database. Must delete incomplete entries before exiting box.
iv. Default hold-down in Shearwalls
Indicates that this hold-down is the one that is used when new walls are created in Shearwalls.
d) Vertical Bolt ( add’l elongation)
This group pertains
to the anchor bolt which connects the upper hold-down bracket or strap to lower
bracket or strap, or to the foundation or some other anchoring mechanism.
i. No/with Anchor Bolt
Radio buttons allow you to indicate that the connection does not have an anchor bolt, disabling the other controls and causing the program to dispense with anchor bolt calculations.
ii. Diameter
Shank diameter of anchor bolt, used in tensile strength and elongation calculation, – can select from list or enter custom size.
iii. Max Length for Given Elongation
The length of anchor rod the manufacturer used in tests to determine the displacement or elongation, usually found in a note in the product literature or evaluation reports. Elongation for any excess bolt length is calculated separately by Shearwalls.
There are checkboxes
in the view for the following options:
i. Shrinkage Compensating Device
If hold-down a mechanical device to adjust for the shrinkage of the perpendicular-to-grain wood between the extreme hold-down fasteners.
ii. Always use Elongation at Maximum Capacity
A checkbox is used to implement the choices described in Method of Determining Displacement in 1c, above.
This Data Group
allows you to enter different hold-down capacities and/or displacements
depending on stud width, thickness, and species group.
i. Elongation/Displacement List box
This box allows you to replicate the tables that appear in the hold-down product literature that have different hold-down capacities and/or displacements for each stud species, thickness and/or width.
The values apply to only one bracket in a two-bracket hold-down.
ii. All
Entering the word “All” means that the capacity and displacement applies to all values of the thickness or width width of the thickness or depth.
iii. New
Creates a new record corresponding to a line in the table of product information.
iv. Delete
Delete an entire record consisting of one line of the Displacement table. You must delete any incomplete lines before exiting the dialog.
v. Note
For any line in the table, you can enter a note corresponding to the one that appears in the product literature and/or evaluation report to show in the design results any further restrictions on the use of the hold-down, such as on the wood grade or specific gravity.
There is similar
input for hold-downs at two places in the program – the Wall Input form and Opening
Input form. In each place, a hold-down data group contains the following
input fields:
i. Hold-down drop-list
For both left and right ends, used to select the hold-down to be used from the list in the database.
ii. Single- or double-bracket
A checkbox indicates that the hold-down is double bracket, that is, the displacement and maximum anchor bolt length entered in the hold-down database applies to only one-half of the assembly, and is doubled for the hold-down assembly used.
iii. Apply to Openings
When this is checked, the inputs apply to all openings on the wall as well as the wall end studs, saving you the effort of updating all the openings manually.
The input of these
data applies to all selected walls.
The following has
been added to the Framing data group
of the wall input view:
i. Grade
The grade value is now active for all materials. Previously it was active only for MSR and MEL, for which grade data is needed for the specific gravity, which affects for shearwall capacity.
ii. Thickness and Width
In wall input view, the stud thickness (b dimension) and width ( d dimension) is input, either by selecting from a list of nominal sections from the database or by typing your own actual value in. The input control behaves in a similar manner to the Width and Depth input in Sizer.
iii. Note that the thickness (b) and width (d) terminology for studs is consistent with product literature, and should not be confused with the width (b) and depth (d) terminology for all members in Sizer.
It is assumed to apply to all studs in the wall, including those at openings and wall ends (which can be built-up from more than one stud.)
iv. Number of End Studs
Typically wall ends are at least doubled and at times more plies are added to provide tensile or compressive strength or connection strength for the hold-downs. The input of the number of end studs at both left and right end has been added to allow the program to select the hold-down capacity and displacement for the Assembly displacement method (see Error! Reference source not found.). The program does not as yet design the built-up studs themselves.
This input has also been added to the Hold-downs data group (see a) above) in the Opening Input view for the wall studs at the hold-down locations at each side of an opening.
New inputs have been
added to the Structure Input form that allow for input of parameters that apply
to all hold-downs on a single building level.
i. Length Subject to Shrinkage
This input indicates the total vertical extent of perpendicular-to-grain wood members spanned by the hold-down device. Typically the depth of the floor joists plus two top plates on the lower level and one bottom plate on the upper level. For ground level, it depends on the sill plate configuration. Used in hold-down wood shrinkage calculations.
ii. Anchor bolt length
This indicates the required length of the hold-down anchor bolt, if one exists for a particular hold-down. Typically the length subject to shrinkage plus flooring material thickness. However, in some situations it could be quite different, for example when wood I-joists are used. The I-joist web is included in the anchor bolt length but not in the length subject to shrinkage.
iii. Context sensitive help
Each of these fields have context-sensitive help explaining their use, accessed via the question mark box at the top of the dialog box.
A new page has been
added to the Settings input for hold-down data that apply to all hold-down
locations in the structure.
Each of the input
controls within this settings page has context-sensitive help, explaining its
purpose and use. If you click on the question mark in the upper left hand
corner of the view, then on the input control a small yellow box appears with
the description of the item.
The following are
brief descriptions of the input fields within the box; for more details, use
the context-sensitive help in the program.
A new group box is
added to include options affect the generation of hold-down forces from
shearline forces on segments.
i. Hold-down Offset
This has been moved to this page from the Default Values page. In addition, the following capability is added:
If a value is entered that is greater than or equal to ˝ a shear wall segment length, the program reverts to the factory default value of 38 mm for that segment. It issues no warning in this case, it is evident only by the placement of the hold-down in elevation view and its position as listed in the Hold-down Design table.
ii. Subtract Offset…in Moment Arm Calculation
A checkbox indicates whether the program subtracts the hold-down offset from the wall length when calculating the overturning moment arm. For the Canadian version, this is disabled and checked, as CSA O86 9.5.6 specifies that the length is to the centre of the end stud(s), implying subtraction of ˝ the end stud width.
iii. Include Joist Depth…in Moment Arm Calculation
A checkbox indicates whether the program includes the floor depth above the wall in the wall height h when calculating the overturning moment arm. . For the Canadian version, this is disabled and checked, as CSA O86 Figure 9.4.5.2 specifies that you include the joist depth.
c) Displacement da for Deflection – Override
Hold-down Properties
The inputs in this
data group allow you to replace the vertical hold-down displacement components
from with constant values for all hold-downs in the program. They also allow
you to specify values for these components if they cannot be calculated or are
not available from the hold-down database for a particular hold-down. A warning
appears in the output if this situation occurs.
i. Displacement
ii. If box is checked, the program uses the input value as the elongation for all hold-downs in the structure that have combined elongation/slippage, overriding the hold-down database value. If box is not checked, it uses the override value only when a value is not available from the database for the stud size that the hold-down is attached to. This value is also used for the displacement of anchorages attached to gypsum-wallboard-sheathed walls, for which there is no design equation in the CSA O86.
iii. Shrinkage
If box is checked, the program uses the input value as the wood shrinkage value for all hold-downs in the structure, overriding the value calculated using moisture content and length subject to shrinkage on each floor.
d) Displacement da for Deflection –
Wood Properties and Construction Detail Settings
Data for hold-down
displacement calculations that cannot be entered independently at each
hold-down location is entered here.
i. Default Length Subject to Shrinkage
Used to enter the proportion of the floor depth as input in the Structure input view, plus the depth of other wood members such as wall top and bottom plates that is subject to shrinkage. This value can be adjusted for individual floors in Structure Input view, it is of primary use in creating defaults for new files for these values.
ii. Crushing of Bottom Plate at End Stud
The deformation of the bottom wall plate beneath the end chord studs at the compression end of the shear wall. The “factory” default is 0.04 corresponding to lumber loaded to capacity for perpendicular compression according to the USA NDS 4.2.6. A value of 0.02 corresponds to lumber loaded to 73% capacity.
iii. Other (miscuts, gaps, etc.)
Additional sources of vertical shear wall displacement are input here at the discretion of the designer. This could include allowance for studs that are cut too short or without square-cut ends
iv. Bolt hole tolerance
The difference between drilled hole diameter in the studs and the diameter of the horizontal bolt shank. For Assembly displacements that include slippage (see 1b, above), any value greater than 1/16” is added to the published displacement, which includes the effect of standard size bolt holes. For separate slippage and elongation, the entire value is added to the calculated slippage.
The program performs
the design check for hold-down capacity at each wall or opening end.
i. Vertical elements
There is currently no mechanism for entering hold-downs at the base of vertical elements transferring a force from an upper storey via a vertical element to a location on a lower story that is not a wall or opening end on that story. so is no hold-down design for those hold-down locations.
For each design case
(wind, seismic, and both force directions), the program checks the capacity of
the hold-downs at each hold-down location against the combined factored uplift
force. The combined force includes:
-
shear
overturning
-
counteracting
dead load
-
wind
uplift
This is a design
check only on a hold-down selected for the hold-down location. The program does
not at this time cycle through various possibilities to find a hold-down.
The program does not
perform the design check at hold-down locations where there are anchorages.
The Hold-down and
Drag Strut table has been split into two tables, one for hold-downs and one for
drag struts. The new Hold-down design table includes hold-down capacity design
information.
i. Hold-down Device
A column has been added to indicate the name of the
hold-down device from the database used at hold-down location. If there is an
anchorage there, the program just says Anchorage.
ii. Capacity
The capacity of the hold-down at that location
iii. Crit Resp.
The ratio of combined, factored hold-down force to capacity. A value greater than one indicates a failed design.
iv. Legend
The legend has been split up to show information pertaining to each column on a separate line, edited for clarity. Information about uplift force for perforated walls for staggered openings added. Lines describing new data added.
v. Notes
Note for dead load factor removed and value of factor placed in legend..
b) Hold-down Displacement Table
New table has been
added giving the components of shearwall displacement for hold-downs. It is
described in the section on deflection output, below.
Shearwalls now
calculates the deflection of each wall segment between openings for each design
case (wind, seismic, rigid, flexible, E->W, W->E) according to CSA O86 9.7. It
uses this deflection to
-
determine
the storey drift, and check that it is within allowable limits
-
distribute
loads to segments within a shearline based on equal deflection of segments
-
determine
rigidities for the rigid diaphragm method of distributing loads to shearwalls
As deflection
analysis can be costly in terms of processing time, this feature is optional.
It is controlled by a checkbox in the design settings.
The equation
implemented is the four-term equation from O86 9.7.1.1 It is
The meaning of the
variables is given in the following sub-sections..
The four terms in the
equation give the contribution to deflection from the following sources, in
order
-
Bending: Bending of vertical shearwall chords (wall segment end studs)
-
Shear: In-plane shear deformation of sheathing
-
Nail slip: Slippage of nails fastening sheathing to top and bottom wall plates
-
Hold-downs: Slippage of fasteners connecting hold-downs to studs, elongation of
hold-downs, wood shrinkage and crushing at hold-down location, and additional
displacement due to mis-cuts, gaps, etc.
For seismic design, the resulting deflection is multiplied by RdRo/Ie, as per NBCC 4.1.8.13.
i. Load Combinations and Factors
For segmented shear walls, the unit shear v is vertically accumulated serviceability shear force, that is, the shear force per unit foot unfactored by the 1.4 load combination factor for wind design, as per CSA O86 4.2.4.2.
For seismic design, it is the same as the force that is used for shear wall design and which appears in the elevation view at the bottom of the shear wall.
ii. Distribution of v Within Wall
The second and third terms of this equation apply to the sheathing, which can be different for each side of a composite wall. Both sides require a shear value v (the third term does so indirectly through en.). Refer to j) below for an explanation of how shear is apportioned to each side of a composite wall.
iii. Distribution of v to Segments Within Shearlines
The distribution of v within a shearline depends on the selection of Shearwall Rigidity per Unit Length and Distribute Forces to Wall Segments based on Rigidity in the Design Settings. For more details, refer to subsection 3 below
The shear wall height
Hs is the distance from the bottom of the bottom wall plate to the
top of the top wall plate, exclusive of floor joists or other building elements
not part of the wall.
The length Ls
is the length of an individual full-height segment between openings, and the
calculations are performed for each segment separately.
f) End Chord Bending Deflection
The first term in the
equation relates to the in-plane bending of the shear wall chords, that is, the
wall end studs.
i. Modulus of Elasticity E
An input field has been added to Shearwalls to allow for input of the grade of the wood end studs. The modulus of elasticity is then taken from the WoodWorks database of material properties.
ii. Cross sectional area A
This is the section area end studs, which are typically built-up members. Shearwalls now allows you to input wall end stud thickness, width, and number of end studs (see C: 4.b) above ), from which the cross-sectional area is calculated.
iii. End Post Composition
Shearwalls does not allow for wall chord posts that are not made up of built-up wall studs but it is possible to model such a situation by typing in a value for the stud thickness, as it has no effect on shear wall design. However you cannot change the wall stud species to the one for the end post without having an effect on shear wall design, which depends on specific gravity. For MSR/MEL you cannot change the grade without having an effect on design.
The second term
relates to the in-plane shear deformation of the shear wall
i. Shear Stiffness Bv
The value for shear –through –thickness rigidity Bv is taken from Table 7.3A-C in CSA O86-09, and from the USA Special Design Provisions for Wind and Seismic (SDPWS) Table C4.2.2B for gypsum wallboard..
ii. Shear Value v
Refer to j) below for an explanation of how shear is apportioned to each side of a composite wall.
The third term is
related to the slippage of nails fastening the
sheathing to the top and bottom shearwall chords, i.e top and bottom wall plates.
i. Fastener Slip en
The fastener slip en is taken from O86 Table A.9.7 for wood panels and for the USA SDPWS Table C4.2.2D for gypsum wallboard. Note that the slip is non-linear with respect to shear-per-fastener Vn for wood structural panels, but does not depend on v at all for gypsum, it is a constant.
ii. Fastener Load Vn
The load per fastener Vn is
calculated by dividing the shear-per-unit-length v by the user-input panel edge
spacing, yielding the force on each edge fastener.
iii. Composite Walls
Refer to j) below for an explanation of how shear is apportioned to each side of a composite wall.
iv. Interpolation
The deflections are interpolated for loads per nail in between the values listed. It is not interpolated for nail size when non-standard nails are input, it uses the value for the smaller nail.
v. Maximum Load Per Fastener
The program limits the fastener shear to the maximum in Table A.9.7. If it is exceeded, it uses the maximum deflection and issues a warning under the Deflection table.
We determined that this level of loading always results in shearwall design failure for which a failure message is already output anyway.
vi. Unseasoned lumber
For unseasoned lumber, that is lumber with fabrication moisture content less than 19%, the deflection values are doubled as per note 2.
vii. Unblocked walls
For unblocked walls, a nail spacing of 150mm is used in place of the actual nail spacing to comply with CSA O86 9.7.1.2.
For unblocked walls,
the shea rwall deflection is divided by the unblocked factor Jub as
per CSA O86 9.7.1.2.
j) Distribution of v to Sides of Composite Wall
For composite walls,
the 2nd and 3rd terms of the equation, shear
and nail slippage, apply separately to each side of the shearwall, which may
have different materials.
i. Equal Deflections
Shearwalls apportions shear to each side of the wall by adjusting the v value until the deflection due to shear plus nail slippage is the same on both sides of the wall. Note that this equalisation is done regardless of whether equalisation of deflections for all segments along a line is being done according to the selection of force distribution design settings described in subsection 3 below.
ii. Zero Shear
Slippage to non-wood-panel materials is a constant, which in many cases creates a larger slippage deflection than is possible for shear plus slippage even when all load is placed on the wood panel. In these cases, all the force is placed on the wood panel side. The deflection for that segment is the nail slippage plus shear from the wood panel side, and does not include the constant gypsum slippage.
Note that in this case, despite the fact that the entire load is assigned to the wood side for purposes of deflection analysis and storey drift, the program still uses the sheathing on both sides of the shearwall for shearwall capacity calculations according to the procedures for combining shear wall capacity in the CSA O86.
The fourth term in
the deflection equation relates to the displacement of the shear wall anchorage
devices and the movement of the wood material at the hold-down location. The
following sections give the various components which are added to give vertical
hold-down displacement da.
Refers to the
elongation in tension of the hold-down brackets or straps plus anchor bolt
elongation, plus the slippage of fasteners attaching the brackets or strap to
the wall studs.
i. Database value
The hold-down database contains the strength-level displacement that occurs at the maximum capacity.
ii. Displacement/Elongation at Maximum Capacity
If this method (see C: 1.c) above ) is selected for a particular hold-down, the program uses the database maximum value regardless of the force.
iii. Displacement/Elongation at Actual Force
If this method is chosen, then the program divides factored hold-down force by the capacity, then multiplies this ratio by the strength-level displacement.
iv. Additional bolt length
In some cases, separate elongation of the anchor bolt is added to the database deflection. This happens when the published displacement or elongation is for an anchor bolt which is shorter than the one input in Structure input view for the level the hold-down is on. The elongation for the additional length is calculated. Note that in this case, for double bracket hold-downs, the published length is doubled before being compared to the actual length in the program.
The elongation of the length L of bolt that is to be analyzed is PL/AE, where A is the bolt cross-sectional area, E is the steel modulus = 29000000 psi and P is the strength level hold-down force at that location.
Refers to the wood
shrinkage that occurs between fabrication and service of the
perpendicular-to-grain wood members spanned by the hold-down.
It is calculated when
the hold-down does not include a shrinkage compensating device.
i. Calculation
The vertical shrinkage displacement is 0.002 x (% fabrication moisture content – % in-service moisture content) x shrinkage length for that building level from the Structure input view.
ii. Moisture content input
The fabrication and in-service moisture content are input in the Design Settings. Previously you could input only whether it was greater or less than 19%, for use in nail withdrawal design. Now the actual moisture content is input.
iii. In-service Greater than Fabrication
If for some reason in service moisture content is greater than fabrication, shrinkage is set to zero.
The wood crush as
input in the Hold-down settings is applied to all hold-down locations in the
program. Typically ranges from 0.2 – 0.4”
The additional
components in the “Other – miscuts/gaps” input of the Hold-down settings are
applied to all hold-down locations in the program.
i. Wood panels
Vertical displacement of anchorages as opposed to hold-downs is determined for walls with wood panels via the equation in 9.7.1.1 for this situation. If the wood construction of one side of the wall differs with the other in any way, both sides are calculated and the smaller deflection of the two is taken. This is equivalent to ignoring the contribution to stiffness of the weaker side.
ii. Gypsum wallboard
For walls sheathed entirely with gypsum, the displacement over-ride from the Hold-down settings is used, as there is no guidance for this in the O86. If a wall has wood on one side and gypsum on the other, the gypsum is ignored.
iii. Unblocked walls
For unblocked walls, a nail spacing of 150mm is used in place of the actual nail spacing to comply with CSA O86 9.7.1.2.
3. Shear Distribution to Wall Segments Within
Shearline
The way that force is
distributed with a line depends on the Design Settings Shearwall Rigidity per Unit Length and Distribute Forces to Wall Segments based on Rigidity.
i. Shearwall Rigidity per Unit Length
In the data group called Shearwall Rigidity per Unit Length, (previously known as Rigid Diaphragm Analysis), a new method has been added to the previous three selections – Use shearwall deflection to calculate rigidity.
If any of the three methods that were in previous versions of the program are selected, then deflections in general will be different for each segment along the line, as distribution within the line is based on shearwall capacity. The largest deflection is taken to be the one used for storey drift calculations.
ii. Distribute Forces to Wall Segments based on Rigidity
This setting has been added to allow you to distribute forces based on the Use shearwall deflection to calculate rigidity choice to each wall within the shearline based on rigidity. If checked, the program will attempt to equalise deflections along the shearline. If it is not checked, distribution within the line is based on shear wall capacity, and deflections in general will be different for each segment along the line, and the largest deflection is taken to be the one used for storey drift calculations.
If both the new Distribute Forces to Wall Segments based on
Rigidity box is checked, and the new Use
shearwall deflection to calculate rigidity button is selected, then the
program will attempt through an iterative procedure to equalise deflections on
the shearline, by redistributing the shear force v to the segments until the
deflections calculated with 9.7.1.11 are the same.
Because deflection is highly dependent on aspect ratio of the segments, and the hold-down forces and hold-down devices employed at each segment, deflection can be highly variable along a line, so that some segments draw negligible force. Furthermore, some segments have constant components to deflection (non-wood-panel nail slip, hold-down overrides, extra hold-down components) that yield a deflection with minimal loading that is higher than the deflection on other segments even if all the shearline load was applied to that segment.
ii. If these situations occur, the program assigns zero load to those segments that are drawing negligible loads (less than 1 N), and equalises the deflection on the remaining segments. The segment that gets zero force is treated as an opening or a non-shearwall for the purpose of final hold-down and drag strut calculations.
iii. Non-convergence
The mathematical system used to model shear wall deflections along a line is not necessarily determinate. On occasion, the routine is unable to equalise deflections along a line, oscillating between solutions that do not equalise deflections. In this case, the deflections that arise from the last iteration before a limit is reached are used.
If the design setting
Use shearwall deflection to calculate
rigidity is selected, the program determines shearline rigidity for rigid
diaphragm analysis by summing the rigidities of all segments along the line,
where the rigidity is defined as the force on the segment divided by the
deflection of the segment.
If deflections have
also been equalised along the line via Distribute
Forces to Wall Segments based on Rigidity, then this is equivalent to
dividing the total force on the line by the deflection.
If you change the
setting from Use shearwall deflection to
calculate rigidity to Manual input of
relative rigidity, in order to adjust the rigidities, the rigidities that
appear in the input for a particular wall are the sum of the rigidities for all
segments along the line, divided by the wall length.
For seismic design
only, Shearwalls implements NBCC 4.1.8.13 by checking the maximum amplified story
drift for any shearline against the allowable limits on each level, and for
each force direction (E->W, W->E, N->S, S->N).
i. Maximum Deflection
The maximum deflection is the largest deflection on any shearline, calculated as described above. If deflections on a line have been equalised (see 4.a) above), it is the common deflection of all walls on the line. If not, it is the largest deflection for any segment on the line.
ii. Deflection Amplification Factor
The deflections are multiplied by the amplification factor from 4.1 8.13 (2) : Rd Rd / IE . The R values can be input into the Site Dialog, but unless they were over-ridden, they are the values from NBCC Table 4.1.8.9
The importance factor IE calculated from the Occupancy category entered in the sited dialog is used.
b) Allowable Drift Calculation
The allowable drift is
calculated according to NBCC 4.1 8.13 (3)..
i. Story height
The storey height hs for each level is the wall height plus the upper floor thickness.
ii. Occupancy Category
The existing input for Occupancy category from the Site dialog is used.
i. Sway Effects
The program does not implement NBCC 4.1.3.2(12) regarding sway effects, that is, the effect of vertical loading acting on the structure in its displaced configuration.
ii. Rotational Deflection
The program does not consider the effect of rotation, that is, the deflection that is caused by the fact that walls on upper floors are rotated due to the deflection on the floor below. This deflection is not mandated in the NBCC or CSA O86, but is addressed in the APEGBC Technical and Practice Bulletin for .5 and 6 Storey Wood Frame Residential Building Projects. We hope to implement this in a future version of the program.
A new table has been
added showing the storey drift calculations for each level and force direction
on that level, and indicating success or failure of the storey drift check.
Refer to 6.f) below for details.
i. Shearwall Relative Rigidity
In the Design
Settings Table, to reflect the changes in the Settings Input, Rigid Diaphragm Analysis is renamed Shearwall Relative Rigidity. The choices
have been modified to be more explanatory. The new input field for deflection says Deflection-based stiffness of wall elements,
ii. Design Shearwall Force/Per Length
This corresponds to the new checkbox in the input Distribute Forces to Wall Segments based on
Rigidity. If this is checked, it says Deflection-based
stiffness of wall elements, if not it says Based on Wall Capacity.
Because of the need
to add information for deflection design, the shear walls materials table has
been split into two tables, one for sheathing materials and one for framing
materials.
i. Sheathing materials
- Material name: The material name has been expanded somewhat from the abbreviated name in previous versions, but is still not the full name that appears in the input view.
- Bv: A column has been added for the value of Bv from Table 7.3A-C in CSA O86-09, and from the USA Special Design Provisions for Wind and Seismic (SDPWS) Table C4.2.2B for all other materials.
ii. Framing materials
For the framing materials table, only one line is needed for each wall design group, instead of the two needed for sheathing materials on each side of the wall. The fields that have been added are
-
Stud grade
- Stud thickness b (actual)
- Stud width d (actual)
- Modulus of elasticity E, in millions of psi or MPa
A note has been added below the table saying
Check manufacturer requirements for stud size, grade, and specific
gravity (G) for all shearwall hold- downs.
Columns have been
added for the anchor bolt length and the length subject to shrinkage, as input
in the Structure Input view.
d) Hold-down Displacement Table
A table has been
added to show the components of vertical hold-down displacement da due to the
main elongation, displacement, slippage, shrinkage, crush, and additional
sources. It has the following fields.
i. Wall and Segment
The wall segment between openings is shown as e.g.
B-3, 2 = second segment on Wall 3 on Shearline B.
ii. Force Direction
E->W, N->S, etc. Can be “Both” if the data is identical in both directions because forces and hold-downs used are the same. In that case only one line is output instead of two.
iii. Hold-down
The hold-down name from the database that is selected at the tension end of the segment. There is limited space for the name, so it may be truncated.
iv. Uplift Force
The unfactored hold-down force at that location, including force transferred from floors above, and including the dead, shear and overturning components..
v. Elong/Disp
This gives the vertical displacement for hold-downs, that is, the combined elongation and slippage
-
Manuf – This is the displacement for the
hold-down with the maximum anchor bolt length given in the manufacturer’s
literature, or with no bolt contribution those hold-downs that do not include
it
-
Add – This is the elongation additional bolt
length in excess of the manufacturer’s maximum, or the elongation of the entire
bolt for those hold-downs that do not include anchor bolt elongation.
- da – Vertical displacement due to elongation = Manuf + Add
vi. Slippage
This input does not apply to the Canadian version of the program, and dashes (-) appear in these columns.
vii. Shrinkage da
The calculated displacement due to wood shrinkage. The moisture contents appear in the legend below, and the length subject to shrinkage on each level appear in the Story Information table.
viii. Crush + Extra
The value of wood crushing plus any additional components entered in the hold-down settings appears in one column. Although this column usually holds the same value for all segments, it is possible that at some locations the crush is zero because there is no compression force at the usual compression end of the shear wall.
ix. Total da
The total vertical displacement for each segment, or sum of the displacement, shrinkage, crush, and additional displacements, is output in a column.
x. Hold-down deflection
The resulting horizontal in-plane segment deflection from the hold-downs, or da multiplied by the segment aspect ratio Hs/Ls, is output in a column. This value is then transferred to the Deflection table. ‘
xi. Anchorages
For anchorages, in place of the displacement value, the program outputs, e.g.
(nu = 153 )
giving the value of the unit lateral nail resistance N from O86 10.9.4, needed in the equation for anchorages in 9.7.1.1.
xii. Legend
The legend spells out the calculations that are used to arrive at each value, giving the value of any needed data not in the table such as percent moisture content and steel modulus of elasticity.
i. Wall and Segment
The wall segment between openings is shown as e.g.
B-3, 2 = second segment on Wall 3 on Shearline B.
ii. Wall Group
The wall design group
iii. Force Direction
E->W, N->S, etc. Can be “Both” if the data is identical in both directions because forces and hold-downs used are the same. In that case only one line is output instead of two.
iv. Wall Surface
Some of the columns (shear deflection and nail slip) have different values for different sides of the wall. To calculate them, different v values for each side of the wall are used as well. Therefore for each segment, if it is a composite wall, there are two lines output.
v. Wall surfaces are output as they are in the shear table, as Int or Ext for perimeter walls, and 1 or 2 for interior walls.
vi. Shear v
The unfactored unit shear value on the segment (that is, strength level shear for seismic design) is output. The proportion that goes into each side of the wall for composite walls is given.
This value depends on the distribution method input in the Design Settings, and when deflections are equalised, in many cases it can be zero. See 3.b)i above.
vii. Segment width L
This is the full length of the segment between the outside edges of the wall end studs.
viii. Wall height H
Although this does not change for all segments within a level, it is output in a column as it is integral to the calculations.
ix. Bending
For the bending component, the following are output on the first of the two lines for the wall segment:
- End stud section area A
- Resulting deflection
x. Shear Deflection
The calculated shear deflection is output on both lines for the wall segment. The legend shows the calculation.
xi. Nail slip
The following values are shown for the nail slip:
- Shear force per panel edge fastener Vn
- en value from from O86 Table A.9.7 for wood panels and for the USA SDPWS Table C4.2.2D for gypsum wallboard.;
- Resulting deflection
If the value exceeds the maximum value in the Table A.9.7,
the maximum value is used. The program
places an asterisk beside the value and issues the following warning.
*WARNING - Maximum load
per fastener Vn from Table A.9.7 exceeded. Maximum Vn used but it
underestimates actual deflection.
xii. Hold-down Deflection
This value is transferred from the Hold-down Displacement table, where the components of hold-down displacement are given.
xiii. Total Deflection
Deflection from
bending + shear + nail slip + hold-down, as per O86 9.7.1.1
Note that shear + nail slip should be the same for both sides of a composite wall, or else one side has zero force and the shear + nail slip for the other side is used. If his is not the case because the numerical procedure failed, the largest shear + nail slip is used.
xiv. Legend
The legend spells out the calculations that are used to arrive at each value, giving design code references and where to find data not in this table, e.g. the Stud modulus of elasticity in the Framing materials table.
A table has been
added to the program to show the storey drift calculations ASCE 7 equation
12.8-15 and the allowable storey drift from ASCE 7 Table 12.2-1. The allowable
drift is shown for each level; the maximum storey drift for any shear wall on
the level is shown on one line for each force direction below the allowable
values.
i. Wall height
The wall height h is shown for each building level, along with the storey height hsx for that level, which is the wall height plus the upper floor thickness.
ii. Allowable drift
The allowable drift calculated according to NBCC 4.1 8.13 (3) is shown for each level only.
iii. Amplification Factor Rd Ro
The value of the force modification factors Rd * Ro as they are used for the amplification in 4.1 8.13 (2), are entered on each line. Note that these values can be different for different force directions.
iv. Importance Factor I
The importance factor I calculated from the Occupancy category entered in the sited dialog. This is the same for the entire structure, but is repeated in the table to show all variables for a calculation on the same line.
v. Maximum Deflection and Line
For each force direction on each level, the table shows the largest of the deflections on any shearline in the force direction as well as the line the maximum was on.
vi. Amplified Deflection
The program shows the maximum amplified deflection on the same line.
vii. Response Ratio
The ratio of the maximum amplified deflection to the maximum allowable is shown.
viii. Failure Message
The program places an asterisk (*) beside any response ratio that is greater than 1.00. A red failure message appears below the table.
ix. Legend
A legend has been added explaining each column in the table.
To all the above
tables a legend has been added to the table or an existing legend improved such
that it shows detailed information pertaining to each column on a separate
line.
h) Show Menu and Display Options Toggles
For all the above
tables, items have been added to the Show
menu and the Display checkboxes in
the Options settings that allow you
to turn off the tables in the screen display and in the printed output, to
reduce the volume of output, similar to all other tables.
i. Segment Forces
The force on each shear wall segment arising from the distribution of forces described in 3 above are depicted by small arrows at the top of the wall at each segment, with the force in pounds on that segment shown.
D: Shearwall Design Iterations
This section refers
to the iterations needed to design shearwalls for the unknown values in order
to determine the stiffness and/or capacity needed for load and force
distribution, then to go back and redesign based on the new load distribution.
a) Structural Iteration for Irregularities
For seismic design,
the program went through two iterations of designing the entire structure as
follows.
i. Iteration 1
The program designed using the user-input method of designing for hold-downs and drag struts.
ii. Iteration 2
The program determines irregularities on the structure, and if Applied Force had been used as the method of determining hold-down and drag strut forces, the program program redesigns the entire structure, determining hold-down and drag strut forces for the shearlines affected by irregularities by shearwall capacity, to comply with NBCC 4.1.8.15-6 where applicable.
i. Rigidity based on Shearwall Capacity
The program designed walls for flexible diaphragm design, and then used the rigidities based on the capacity of those walls for rigid diaphragm shearwall design. .
It did not go back and recalculate rigidities for the new walls designed for rigid design, and continued to show the flexible-designed shearwall rigidities as the rigidities of the rigid-designed walls.
ii. Equal Rigidity or Manual Rigidity Entry
For these distribution methods, the rigidity is independent of shearwall design, so no iterations were necessary.
Before the
introduction of deflection analysis, if you selected not to allow dissimilar
materials on the line, it was possible to determine load distribution within a
line based on relative capacities and identify the critical wall for design
ahead of time and an extra design iteration was not needed.
If dissimilar
materials are allowed, the program must design each wall separately so that the
design could result in a redistribution of loads, and a iterations were peformed
to design the wall and redistribute loads until a there was no difference in
walls designed.
d)
Hold-down vs
Anchorage Loop
If the user chooses
to allow anchorages, the program does several iterations of design based upon
trying to counteract a failed design by increasing the Jub factor. On the first
loop it places the hold-downs only where they are required by CSA O86. Then it
places them at the ends of the shearline, then at the ends of all walls, then
at the ends of all segments.
This acts in concert
with the Design Setting that indicates whether hold-downs should be at those
locations, and the setting that allows you to over-ride these locations to
achieve design.
2. Structural Iteration for Irregularities
The program still
performs two designs of the structure for the purposes of determining
irregularities, however this is now part of a larger design sequence that
includes a third run for final design check.
Note that the
iteration for irregularities has taken on added significance because of the
introduction of deflection analysis. If the program automatically calculates
certain hold-down forces using shearwall capacity , these hold-down forces
impact the hold-down component of the deflection equation.
3. Design Iterations Per Level
i. Stiffness Analysis
Now that load distribution can be affected by the stiffness due to deflection analysis, it is no longer possible to predict ahead of time which wall segment will be critical design, and an iterative procedure is required.
ii. Rigid Analysis
It is an improvement to the program to redesign walls for rigid analysis based on the stiffnesses from the rigid analysis. This improvement became especially important because of the variations in wall rigidity that result from deflection analysis.
Therefore, on each
level, first for rigid, and then for flexible, the program runs through two
iterations of shear wall design.
The first iteration
is used to design shear walls to determine rigidities and capacities for load
and force distribution for the second, final design iteration.
i. Distribution to Shearlines
For flexible analysis, distribution to shearlines is independent
of shearwall design, and is the same for both iterations.
For rigid analysis, if Shearwalls
have equal rigidity or Manual input
of relative rigidity is selected, then the relative rigidity of the
shearlines is also independent of shearwall design, and is calculated by the
sum of the wall lengths multiplied by either 1 or the manual input.
For the other rigid analysis options (Use shearwall capacity or Use
shearwall rigidity), the rigidities of the shearwalls designed on the
second iteration of flexible design
are used as the rigidities for the first iteration of rigid design.
ii. Distribution within Line
With shearline forces established, on the first iteration, for both flexible and rigid design:
If Distribute forces to wall segments based on rigidity is not selected, or if Shearwalls have equal rigidity is selected, the program distributes equal force per unit foot to segments within the line.
If Manual input of relative rigidity is selected, then the user input rigidities are used to distribute forces to each shearwall.
Otherwise, the force is distributed each shearwall using the relative capacities of the shearwalls. Since walls are not yet designed, the deflections are not known at this point, and the selection of Use shearwall deflection to calculate rigidity must use the capacity method on the first iteration.
iii. Shearwall Design
With possibly different forces distributed to each wall, the walls
are designed. This shear wall design is used to determine rigidities for the
second iteration.
i. Force distribution
If Shearwalls have
equal rigidity or Manual input of
relative rigidity is selected, there is no reason for a second iteration,
and the program stops at the first iteration, and delivers design results for
the shear wall design for the first iteration.
Otherwise, using the walls designed with iteration one, the program determines the force distribution using rigidities derived from either shear wall capacity or deflection analysis, according to the design setting selected. The force distribution is for distribution of loads to shearlines using the rigid diaphragm method, and distribution to forces within shearlines using both methods.
ii. Distribution to Shearlines
The rigidity of a shearline is estimated using the capacity method by the capacity of the designed wall on that shearline, in lbs/in, and by the deflection method by
Σ Fi/DI,
where Fi and DI, are the forces and deflections on each segment. If forces are also distributed within the line based on deflection, so that deflections are equalised, this is just F/D, the total force over the common deflection. Loads are then distributed to the lines using the torsional rigid diaphragm method.
iii. Distribution within Shearlines
If the setting Distribute forces to wall segments based on rigidity is selected, for both the rigid and flexible method, then the program calculates the force distribution on the line based on relative rigidities of segments on the line. Otherwise equal force distribution is assumed.
If Use shearwall deflection to calculate rigidity is selected, then different forces are placed on all full-height segments.
If Use shearwall capacity is selected, the different forces can be placed on each shear wall. At this stage, the program distributes loads based on the actual factored capacity of the walls from the last iteration.
iv. Design
Each shear wall is again designed. Note that these walls
may have different deflections and possibly capacities than those used to
distribute forces to design the walls; this is dealt with by the Final Design Check,
below.
It would have been
possible to continue this process to further iterations. This was not done
because:
i. Distribution of Loads to Shearlines
An iterative procedure for rigid diaphragm analysis would tend to concentrate loads on a particular shearline. That is, a heavily loaded line would require more capacity, would become more stiff, would draw more load, and so on. This is not a desirable shear wall design for other reasons.
ii. Final Design Check
The final design check described below now traps and indicates to the user those rare cases where walls passing on the second iteration failed the final design check. This was deemed preferable to the increased processing time that would be needed for all designs if there were more iterations.
iii. Non-convergence
If we established the condition for ending the iterations that shear wall design did not change from one iteration to the next, it would be possible for the procedure to oscillate from one solution to another without ending.
For the entire
structure, forces are distributed based on the capacities, stiffnesses, and
shear resistance distribution of the walls designed on the second per-level
iteration and the hold-down and drag strut procedures determined value from the
second structural iteration for irregularities, if one was needed.
The designed walls
are then checked against the new forces, and the results reported in the Design
Check output:
i. Output Report Consistency
This ensures that the output reports show the force distribution, the r value, the shear wall deflection, and shear wall design capacity from the same set of walls.
ii. Possibility of Failure
Although it rarely occurs, it is possible that the walls designed on the second iteration cannot withstand the forces created from their rigidities. The design check shows this situation, indicating to the user via the following warning message that the problem is to do with design iterations and can be remedied by more manual input.
Warning: For
shearline(s) [ A, B, C, ..., 1, 2, …], a shearwall that passed the design check
on the initial run failed the final check when forces were redistributed to
shearlines and/or wall segments within a line using [ shearwall deflection,
shearwall capacity]. Try to adjust wall materials to achieve a passing design,
or choose a different force distribution option in the Design Settings.
E: Other Engineering Design Issues
1. Shear Strength of Unblocked Shearwall (Bug 2250)
The shear strength
for an unblocked wood-based shear wall, according to the asterisked note to CSA
O86-01 Table 9.4.4, is the shear strength for a blocked shear wall 600 mm stud
spacing and 150 mm edge nail spacing, regardless of the actual composition of
the shear wall, multiplied by the Jub factor. Shearwalls instead used the actual nail and
stud spacings for the shear wall to determine shear strength, ignoring the
note. Since 600 mm stud and 150 edge spacing are the maxima, this created
non-conservative resistances. The program now applies the note.
Note that the
asterisked note for a strength increase in Table 9.5.1A is not applied, even if
the actual stud spacing is 400 or less, because it is overridden by this
requirement.
2. Gypsum Wall Board for Wet Service Conditions (Bug 2251)
If wet service conditions are selected in the
design settings, the program now does not consider the shear resistance for
gypsum, as per Table 9.5.1B note 2. A note appears under both the Seismic
Information table and Shear Results table to that effect.
3. Segment Output in Seismic Shear Results Table (Bug 2275)
In the Seismic Shear
Results table, the segment rows indicated that the Fv and Fv/L values were for
"Both" directions when the actual values for the opposing directions
were different. The values that were shown for "Both" were for
the S->N and W->E directions, and
the opposing directions were not shown.
The problem did not
occur for the "Wall" rows when there were no segments.
4. Gypsum Wallboard Storey Capacity for One Directional Loading (Bug 2273)
In the 'Percentage
Storey Shear Resisted by Gypsum Wallboard' table, the gypsum wallboard (GWB)
capacity was reported as zero when there
is a force in only one direction of a
particular orientation, e.g only North-South, but not South->North. This
problem would ordinarily occur only in test cases and not realistic structures.
5. Percent Gypsum Shear for Asymmetric Wind Loads (Bug 2264)
The percentage storey
shear resisted by gypsum for shearlines where the wind shear in one direction
is not equal to the wind shear in the opposite direction incorrectly used the
shear load in the opposite direction in the calculation. This has been corrected.
F: Load Distribution and Accumulation
1. Bi-Directional Seismic Rigid Diaphragm Analysis (Bug 2282)
The program did not
do seismic rigid diaphragm analysis in both force directions, it only analysed
east-to-west and south-to-north directions. This became problematic when
deflection analysis was added to the program; due to hold-down configuration,
stiffness can be different in opposing directions, so that rigid analysis is
required in opposing directions.
Note that direction
of force was being considered when distributing shear within the line, based on
the stiffness of individual segments, as it should be.
In Plan view, the
seismic shear force was displayed as a bi-directional force, now it is
displayed as a directional force (similar to how wind forces are displayed).
When you select to display critical forces, the worst case seismic force on
each shearline is now displayed.
2. Wind Uplift Loads over Openings (Bug 2132)
When a wind uplift
load is applied to an entire wall line, the uplift load did not appear over
openings in elevation view, and the load over the openings was not distributed
to the hold-down forces at the sides of the opening.
3. Shearlines with Zero Capacity and Non-zero Shear Force (Bug 2211)
Shearlines that have
no shear capacity because some of the constituent walls are composed entirely
of segments that are too narrow, and all the other walls on the shearline are
sheathed entirely with gypsum and Ignore gypsum setting is selected, would nonetheless receive
shear load. This resulted in failed
shear walls and a warning that Jhd factor is less than zero. The
program now identifies this case and does not include the shearline line in the
load distribution process, for both rigid and flexible loading.
4. Full Height Sheathing Output for Excluded Gypsum Walls (Bug 2355)
Shearwalls that have
no shear a capacity because they are sheathed entirely with gypsum and Ignore gypsum setting is selected would
show a non-zero length of full-height sheathing in the Shearline, Wall and Opening Dimensions table. Now the program shows
a zero length in this case. The legend
at the bottom has been modified to indicate that the FHS column refers to the full
height sheathing available for shear
resistance.
Because the Ignore gypsum setting is set separately
for seismic and wind design, an extra column has been added to the table to
show full-height sheathing length for wind and seismic separately.
5. Accidental Eccentricity Reference in Log File for Medium Rise Wind Loads
(Bug 2295)
In the log file, the
reference to the accidental eccentricity for low rise wind loads, used the
seismic NBCC clause 4.1.8.11 10) rather than the correct wind reference: NBCC
Structural Commentary 36, 37 Fig I-16 Case A.
The seismic reference
might lead one to believe that 10% D should be used rather than the zero
accidental eccentricity the program is correctly using.
6. Low-rise Wind Load Rigid Diaphragm Cases in Log File (Change 91)
The titles to the
sections in the log file for low rise rigid diaphragm wind load cases have
changed from Longitudinal and Transverse to Case A and Case B to match the
terminology in the NBCC Structural Commentary Figure I-7.
Fixed “Cancel” of
design such that it cleans up what it is doing on the current floor and then
exits. Previously it was doing large amounts of unnecessary processing, and the
box would freeze on the screen, but not do anything or affect the program.
1. Maximum Seismic Base Shear Vmax in Log File Output. (Bug
2054)
The log file did
indicate when the maximum seismic base shear value Vmax from
4.1.8.11 2) c) governs. In this case, the program showed this value as the
resulting base shear V, but it does not correspond with the S value shown, or
with the equation that is shown above.
Now a note is output
below the Calculation of the total design base shear table noting that V is
calculated using 4.1.8.11 2)c) equation, and (unless 4.1.8.11 2) c) used) has been added to the base shear
equation:
2. Input of T Greater than Maximum (Bugs 2281, 2130)
Previously, the
program did not prevent you from entering a value of T in the site information
box greater than the maximum limit on T given by NBCC 4.1.8.11 3) d) iii), that
is, 0.1(h)^0.75. A period this entered would be used for load generation
without any warning or note appearing in the output.
Now the program does
not allow you to enter a period greater than the maximum allowed.
3. Vertical Location of Upper Wall Load (Bug 2107)
The bottom of
generated wind area loads on the upper portion of walls was not midway up the
wall, instead midway plus ˝ the floor depth. This created a higher z-value used
for the evaluation of the exposure coefficient and the topographic factor. The
effect was conservative and small, creating wind loads at most 3% too
heavy.
4. Area Load Tributary Width and Magnitude Reporting (Bug 2108)
Automatically
generated area loads on the lower half of walls are given a vertical tributary
width that is derived from the upper half of the storey, so it includes the
joist depth of the storey above when it shouldn’t. These incorrect widths are
shown in the load lists in the load input screen and Design Results.
The incorrect width
is used in creating the load intensity shown in these lists, so that the total
load on the wall segment remains the same as if the correct tributary width was
used. The line load created on the diaphragm and shown in plan view is also
correct, so this problem has no impact on force generation or design.
The bars that appear
at the top of the Plan View, Elevation View, and Design Results View have been
modified as follows
i. Settings
The Settings… item has been removed to the right of the bar, in order that items that refer to the operation of the window appear first.
ii. Hold-down and Log File Items (Change 60,68)
iii. The button Hold-downs has been added to invoke the Hold-down database editor, and the button Log File has been added to open the Log File. These appear to the right of the bar.
iv. Ellipses Removed (Change 60)
Ellipses (…) have been removed from those items that do
not lead to a dialog box appearing – Show,
View, Preview, Wide View.
v. Starting Out (Change 76)
The button that was called “Help” that invoked the “Getting Started with Shearwalls” box has been renamed Getting Started… It remains visible now throughout program operation; it used to disappear after walls were extended upwards.
i. Metric Force Input Precision (Change 80)
The number of digits displayed after the decimal place when forces input as kilonewtons are refreshed has been increased from 1 to 2.
b) Getting Started with Shearwalls
This box has been
updated to
-
better
describe the sequence of program operations, for example creating openings for
all levels before extending walls.
-
describe
more fully the purpose of blocks as eventual roof shapes
-
better
indicate how to perform key operations, such as the shift-key wall move and
navigating within the design results output
-
add the
Load Input, Design, and Design Results steps to complete the process
-
include
information about hold-down connections and deflection analysis
i. Status Bar Messages (Change 58)
Status bar messages have been added to explain the use of each of the input fields in the box.
i. Default Sheathing Orientation
The default sheathing orientation for standard walls has been changed from vertical to horizontal sheathing.
ii. Both Sides Same for Sheathing Thickness and Orientation (Change 74)
After checking the checkbox that indicates both exterior and interior surfaces have the same sheathing materials specification, and making changes to the sheathing thickness or orientation, the sheathing on the opposite side to the one you were editing before you checked the box was not being updated for the changed property. This results in walls that are supposed to have the same sheathing on either side not being treated as such in the design engine. If the sheathing also has unknowns, it is possible for the design engine not to design the interior side (Side 2), outputting question marks in place of materials specifications and zero design capacity.
iii. Unknown” Exterior Gypsum Wallboard Thickness (Bug 2200)
If gypsum wallboard sheathing with more than one choice of
thickness is selected as the material for the exterior surface, the choice of
"unknown" was unavailable from the drop-down list of thicknesses to
choose from.
Now, "unknown" is available, unless there are
structural wood materials on the other side of the wall.
iv. Building Level in Wall Materials Input Label (Bug 2291)
The label on the group box surrounding the wall materials often showed a building level other than the one you had selected to modify the materials on. It now shows the correct level.
v. Five Ply Plywood for 12.5 mm Thickness (Change 84)
Although you could select five-ply plywood for plywood of 12.5mm thickness, the five plies revert to four plies when the selected wall was no longer selected. This has been corrected.
i. Impact Resistant Checkbox (Bug 2153)
The Impact – resistant checkbox is shown in the Openings view, but has no effect for the Canadian version of Shearwalls
i. Snow Load Proportion Note (Bug 2053)
The note corresponding to the asterisk beside the input of snow mass was missing. It now says “25% used, see NBCC 4.1.8.2” .
g) Default, Options and Format Settings
i. Default Floor Depth
In the Default Settings, the setting Floor joist depth (in) has been renamed Floor depth (in), because the depth includes flooring materials as well as the joist depth.
ii. Default Wall Thickness
In the Default Settings, the Wall thickness has been changed to Wall display thickness, to emphasize that the input affects only the drawing on the screen, and not the actual thickness of the wall studs used for hold-down deflection analysis. The default for that purpose is set via the stud size in the default Standard Wall.
iii. Default Shearline Elevation Offset (Bug 2198)
The default shearline elevation offset has been set to 1 joist depth from 0.5 joist depths.
1/2 of the default 10" joist depth is less than the default plan offset of 6", so that a shear wall on a multi-storey building that was within the plan offset or another would nonetheless be placed on a different shearline, so that it complied with the elevation offset with walls on the level above. For example, a wall offset 6" on the floor below, but not above, would be placed on its own shearline.
The problem was exacerbated by the fact that 1/2 the default joist depth was less than the default snap increment, and walls must be created at least one snap increment apart.Therefore this problem would occur in every case for users using the default Shearwalls settings.
iv. Shearwall Material Options for Elevation View (Bug 2150)
In the Display group in the Options Settings, and the
corresponding menu items in the Show menu for Elevation View,
-
The “Nailing” choice was removed because the
nailing is on the same line as the sheathing.
- An item has been added to turn on and off the legend, to allow for more vertical space.
v. Obsolete Options
The checkboxes for Design Warnings and Shearwall Segments Table have been removed. They were obsolete items that had no effect on the program.
vi. Gridline Snap Increment Setting (Bug 2188)
Changing the Mouse click interval in the View Settings causes the Display Gridlines every __ snap increments to change automatically when exiting the box in order to maintain the same gridline display distance as before the changes. However, it did so even if you had changed the Display gridline” manually. Now, the program checks if it has been changed manually before automatically adjusting.
i. Include Deflection Analysis
A checkbox has been added allowing you to disable the new Deflection Analysis feature, which can be costly in terms of programming time. This checkbox controls other inputs dependent on deflection analysis, such as the Use shearwall deflection to calculate rigidity setting.
ii. Wind Load Design Procedure (Change 105)
Change Wind load design standard to Wind load design procedure. There is only one standard, the choice is of procedures within that standard.
iii. Shearwall Rigidity per Unit Length
The data group previously known as Rigid Diaphragm Analysis has been changed to Shearwall Rigidity per Unit Length, because this rigidity is used for both the distribution of applied loads to the shearlines using the rigid diaphragm method, and for distribution within a line if the Distribute Forces to Wall Segments based on Rigidity box is checked.
A new method has been added to the previous three selections – Use shearwall deflection to calculate rigidity.
Refer to the section in Deflection on Shear distribution within a line for the significance of this setting.
iv. Distribute Forces to Wall Segments based on Rigidity
A checkbox has been added called Distribute Forces to wall Segments based on rigidity. It is active only if
Refer to the section in Deflection on Shear distribution within a line for the significance of this setting.
v. Height-to-width Ratio (Change 104)
The input for maximum ratio, height to width has been removed from the program, as the CSA O86 mandates this ratio separately for blocked and unblocked shearwalls.
vi. Disregard Shear Wwall Height to Width Limitations (Change 104)
A checkbox has been added to allow you to disregard the height to width limitations entirely. This is ordinarily used to allow for proprietary non-wood shear resisting elements.
vii. Moisture Conditions
The moisture conditions allow for entry of the precise moisture content, if the “Use deflection analysis” setting is checked, as moisture content is needed to calculate shrinkage. A moisture content of 19% or greater corresponds to wet service or fabrication conditions upon which design factors are based.
a) Table Headings, Legends and Notes
i. Design Case in Heading
At the top of each table, and at the top of each page of results for each table, the design case is now given in brackets, e.g. (rigid wind design). Previously this just appeared at the top of new pages in the Shear Results table.
ii. Separate Lines
The following legends have been broken into separate lines for each item for enhanced readability:
- Sheathing Materials
- Framing Materials
- Shear Results
- Hold-down Design
- Drag Struts
iii. Additional Information
The following legends have been improved:
- Sheathing Materials
- Framing Materials
- Shear Results
- Hold-down Design
- Drag Struts
Among the more common improvements are
- Adding descriptions for table rows and columns that previously did not have one
- Integrating notes into the legend, and eliminating duplication of information in notes and legend
- Adding design code clause references
- Updating design code references to CSA O86-09
- Changing terminology to match exactly that in the design code
- Referencing other tables when necessary.
iv. Legend-Note Separation
A blank line has been inserted between the legend and the notes for all tables, for better readability.
v. Failure Messages (Change 70)
Any warning message indicating design failure in any way is now in red type. For example nail withdrawal design warnings
vi. Hold-down and Drag Strut Calculation Procedure (Change 83)
The program now indicates in the legend whether the hold-down and drag strut design force shown is based on applied shear force or shearwall capacity. A setting in the Design Settings controls this.
i. Hold-down and Drag Strut Force Calculation Method
Two lines have been added
Drag strut forces based on
Hold-down strut forces based on
These then show Applied
forces or Shear capacity.
The setting had been in the program, but not echoed in the output.
ii. Design Shear Wall Force/Length
A cell labelled Design Shear Wall Force/Length has been added to reflect values in the cell come from the new design setting, Design shear force based on wall rigidity.
iii. Height-to-width Ratio (Change 104)
Despite the fact that the user has no control over this, we still show this value, which is now always 3.5, and added the unblocked height-to-width ratio limit of 2.0
iv. Disregard Height to Width Ratios (Change 104)
This setting is manifested by dashes appearing in the Height-to-width ratio field.
i. Calculated Period (Bug 2279)
In the Site Information section of the Design Results, the calculated period shown was the one entered in the Site Dialog, rather than the period calculated in 4.1.8.11. The entered period is also shown, so these two lines were always the same.
d)
Percentage Storey
Shear Resisted By Gypsum Wallboard Table (Change 80)
In this table, some
of the lines dividing the columns have been removed to make the table have a
more consistent format with other tables.
e)
Components and
Cladding Table
i. No Capacity Message (Change 73)
When a material such as gypsum wallboard that has no sheathing C&C capacity was used on an exterior surface, the program was outputting a warning note saying it failed the withdrawal capacity check, and another saying that the material on the exterior has no shear capacity. Only the second note, about no shear capacity, is output now.
f)
Irregularities Table
and Screen Messages
i. Notes for Drag Strut and Hold-down Capacity Provisions (Bug 2021)
The correction made for version 7.2, listed below, was reverted to the previous behaviour for subsequent versions, 7.21 and 7.22. This correction has been restored.
ii. Reference to Capacity of Elements Supporting Discontinuous Walls (Change 85)
A reference to clause 4.1.8.15-4 was showing up instead as ???. This was in a warning message saying that drag struts and hold-downs on floors below a discontinuity must be designed for the capacity of the upper floor.
iii. Irregularity Check Warning Message Box (Change 86)
The message box that appears on the screen when the design fails due to Irregularity 4 for in-plane stiffness or Irregularity 6 for a weak storey, from NBCC 4.1.8.6, appeared when the irregularities existed in the walls designed for flexible diaphragm analysis only. If these irregularities existed for rigid diaphragm analysis, but not flexible, the box for Irregularity 6 did not appear, and the box for Irregularities 3,4 and 5 either didn’t appear or didn’t mention Irregularity 4 for stiffness. The boxes now appear for rigid analysis when they should.
i. Drag Strut Spelling (change 82)
Wherever the word dragstrut appears in Shearwalls, it has been changed to drag strut.
I: Installation and System Issues
1. Program Data File Locations (Bug
2265)
Because Windows 7 and
Windows Vista operating systems do not allow write access to the Program Files
folders to those users who are not running the program as Administrator, making
it impossible for them to save changes to the stud material database, the
hold-down database, settings, and standard walls, these files are now placed in
a new location by WoodWorks.
It was also necessary
for those users who were not administrators on their computers to enter a key
code each time the program was run.
These restrictions
were more severe on Windows 7 than Vista.
The program now
stores the support files for the program in the following folders
Windows 7/Vista:
C:\Users\[username]\AppData\Local\WoodWorks\CWC\Canada\8\
Windows XP
C:\Documents and Settings\[username\]Local
Settings\Application Data\WoodWorks\CWC\ Canada \8\
The program also saves the files to the
following folders:
Windows 7
C:\ProgramData\WoodWorks\CWC\
Canada \8\
Windows XP
C:\Documents and
Settings\All Users\Application Data\WoodWorks\CWC\ Canada \8\
These are
repositories for the files to be copied to each new user’s data folders when
they first use the program. This allows a system administrator to install the
program, but others to use it without restrictions.
A more complicated
set of procedures for network installations is described in the Read Me files
for each program.
i. Crash for Non-Administrators Due to Temporary Log File (Bug 1990)
For Windows Vista and Windows 7 operating systems, those
users who do not have administrator privileges can experience a crash when
running a project that has previously been designed, Shearwalls would crash.
Deleting or renaming the log file in the project folder prevented the crash.
The program now places the temporary file that it uses to construct the log file in the folder designated by Windows for program data, preventing the crash.
ii. Log File Closing (Change 75)
The program now automatically closes the log file when a document is closed. Previously the log file remained open even if Shearwalls was exited. This occasionally caused program crashes when a log file remained open for a file that was then reopened.
Shearwalls 7.22
– Feb 9, 2010 - Design Office 7, Service Release 3
This version was
released to correct the following problem that was introduced in 7.21
1. Framing Material and Species Input (Bug 2114)
When the framing
material or species was changed In the Wall Input form, the program did not
record the change, instead reverting to the default value the next time that
input field was accessed, or when the building was designed.
As a result, the calculation
for shear capacity always used the density value Spruce-Pine-Fir,, which
according to NBCC 9.4.3 has a species factor of 0.8, therefore is conservative
for Douglas Fir and Hem-Fir materials and non-conservative for Northern
Species. In addition, the desired material specification does not appear in the
Design Results output.
This problem precluded
the use of MSR and MEL materials, or any custom materials you enter in Database
Editor.
It was still possible
to change your framing material and species specification via standard walls –
you first create a standard wall, select the desired materials, and then select
the standard wall as your shearline wall.
The following
changes were also made:
3. Relative Rigidity for Standard Walls (Bug 2120)
When the Shearwall Rigidity design setting is not
Manual input, the program now allows
the input of a relative rigidity for Standard Walls. It can then be used on
walls created from those standard walls for projects with different rigidity
settings, or if you change the rigidity setting in the same project. Previously, it the program disabled the
rigidity input, and displayed the same for standard walls as it does for
regular walls, that is to show “1.00 (Wind design)” and assign a value of
1.0.
4. Name Field for Standard Walls (Bug 2119)
The Name input for Standard Walls was widened to coincide
with the length of the wall names in the dropdown list.
5. Unsorted Openings* (Bug 2099)
This bug was never
detected in the Canadian version of the program, but the fact it was in the USA
version leads to the strong possibility that it could occur for Canada as well:
Although the program
sorts the openings input in Opening view from left to right on the wall,
occasionally the sequence of openings becomes unsorted in the course of program
operation. Attempts have been made to
capture this problem and resort them to avoid problems that were occurring in
the following program areas.
a)
Full-height
sheathing Determination
We have now ensured
openings are sorted in determining the length of full-height sheathing
segments, and all the effects this has on force distribution and shearwall
design.
b)
Hold-down force
Determination
We have now ensured
openings are sorted in determining the segment length to be used in hold-down
force calculations
c)
Drag strut Force
Determination
We have now ensured
openings are sorted in determining the length of shearwall segments to be used
in drag strut force calculations.
d) Shearline Force Determination
We have reduced the
possibility that unsorted openings are affecting shearline force calculations,
but it is possible that unsorted openings could still be having an effect in
this area. If you see suspicious shear results, check for unsorted openings; it
may be necessary to re-enter the openings.
Shearwalls 7.21
– Oct 1, 2009 - Design Office 7, Service Release 2a
This version was
released to correct the following problems that were introduced in 7.2
1. Reversal of Seismic Sa Values (Bug 2060)
In the Site dialog,
the value of the damped spectral response acceleration factor Sa(T=0.2) showed the
value for Sa(1.0), and Sa(1.0) showed the value for Sa(0.2). If you had entered these values manually,
then these incorrect values were also used in the load generation process, so
that the generated base shear was typically much less than it should be,
resulting in non-conservative design. These values were also reversed when
displayed in the Design Results output and log file reports.
Note that the values
of Sa(1.0) and Sa(0.2) were also reversed when loaded into the Site dialog
boxes from the table of values for the city selected in the Design Settings. As
the values were reversed again when used in design and output, if they were not
changed in the Site dialog, the correct values were used to generate seismic
loads and appeared in the output reports. However, if the values in the Site dialog were
corrected before design, or if values for a city not in the list were manually
input, then the Sa(0.2) and Sa(1.0) values were switched in the design process,
causing significantly non-conservative loading.
2. Crash for Non-shearwalls (Bug 2080)
In version 7.2, if
there are any non-shearwalls on the structure, and the “Disable gypsum
contribution” setting is not set, the program crashes when performing Design.
This has been rectified. Note that the “Disable gypsum” setting is not the
default setting, so that this crash was highly likely to occur.
The following
problems were also corrected:
3. Random Design Crash (Change 50)
B: A random and very infrequent crash on shearwall
design was removed.
1. Version History in Installation (Change 51)
It is now possible to
access this document directly from an icon on the start menu rather than
indirectly through the Readme files.
Shearwalls 7.2 –
July 30, 2009 - Design Office 7, Service Release 2
This
is a free service release update to address issues submitted by our users since
the release of version 7, and to implement more improvements to the software.
The links below lead to descriptions of the changes made to
Shearwalls for Version 7.2.
1. Seismic Response Modification Factor (Bug 1904)
1. Shearline Force Distribution
2. Maximum Gypsum Wallboard Contribution (Feature 131)
4. Component and Cladding (C&C) Wind Design
D: Input and Program Operation
3. Material and Structural Data
5. Components and Cladding Table
6. Drag Strut and Hold-down Table
7. Seismic Information and Seismic
Irregularities Table
8. Gypsum Wallboard Table (Feature
131)
10. Rigid Diaphragm Analysis in Log File (Bug 1803)
1. Windows Metafile Example (Bug 1966)
1. Seismic Response Modification Factor (Bug 1904)
The message upon seismic load generation that allows you to change the NBCC
seismic response modification factor R to the one appropriate for the materials
being used has been improved in the following ways:
The program now applies the message on changes to both Rd and
Ro in NBCC 2005 4.1.8.9, rather than just R, as in the NBCC 1995.
Currently, when gypsum materials are present, the program allows you to
override the warning message and use an Rd value greater than 2.0,
the value in NBCC table 4.1.8.9 for gypsum and wood in combination.
Now the program gives you a choice of automatically selecting the Disable gypsum contribution or changing
the R value to one less than or equal to 2.0.
The program now warns you if you have unnecessarily entered a value of
2.0 or less, corresponding to gypsum materials, when there are no such
materials in a particular direction. It allows you to change the value to 3.0,
the value for wood shear walls in Table 4.1.8.9
c) Disable Gypsum Contribution Setting Checked
The program now warns you if you have unnecessarily set the Disable gypsum contribution design
setting with an Rd value of 2.0 or less for a particular direction.
It offers you the choice of automatically deselecting the setting, or
increasing the Rd value to to 3.0, the value for wooden shear walls
in Table 4.1.8.9
d) Analysis in Both Directions
The above messages and actions are taken independently for each force
directions, to comply with 4.1.8.9 (3). The program had been making the changes
to both directions, even if they applied to only one.
a) Building Mass on Flat Roof Overhangs (Bug
1890)
Shearwalls does not create building masses or for those portions of flat
roofs that are part of the overhang, resulting in lower seismic loading for
those roofs due to the absent building mass and snow load. This problem has
been corrected by not allowing structures with flat roofs to have overhangs. To
correct existing projects with flat roofs you need to enter the Roof Input dialog and deselect and
reselect the flat roof. Doing this sets the overhangs to zero.
b)
Irregularities
for Five- and Six Storey Structures (Feature 131)
The program
implements the British Columbia Building Code (BCBC) provision 4.1.8.10 (4) for
5- and 6 storey structures, that Irregularities 4 ( In-Plane Offset) and 5 Vertical Discontinuity, are not allowed for
these structures when IEFaSa(0.2) > 0.35.
The program detects this condition and adds the note to this effect under the
Seismic Irregularities table. A warning note that appears on the screen also
refers you to the APEGBC April 2009 Bulletin for 5-and 6-storey Residential
Buildings, section 3.5.2 c) or www.housing.gov.bc.ca for more information.
c)
Irregularities
Notes for Drag Strut and Hold-down Capacity Provisions (Bug 2021)
The note below the Seismic Irregularity table
and on-screen warning that appear for Irregularities 3 (Vertical Geometry) and
4 (In-plane Discontinuity) and 5 (Out-of-plane Offset) indicated that seismic
design results were not valid because a the capacity of the lower storey within
the discontinuity had a lower capacity than the upper storey, contravening NBCC
4.1.8.15-2. In fact, this clause says that the elements on the lower storey
supporting the upper storey should be designed using the upper storey capacity.
These messages have
therefore been changed to indicate only that the drag strut and hold-down
forces are calculated using the lower storey capacity when they should be using
the higher upper storey capacity. Also, the separate notes have been made for
Irregularities 3/5 and 4, indicating that the capacities are storey capacities
for 3 and 5 and shearline capacity for 4.
a) Structural Wood Panels Required (Bug 1904)
The program now checks that each storey has at least some structural
wood panels on each level, if that is not the case, load generation for both
wind and seismic loads is aborted. This is to comply with CSA O86 9.5.4 and
Table 9.5.4.
b) OSB Construction Sheathing (Change 45)
The program was internally omitting OSB Construction from the list of
wood-based materials, so that it is possible that buildings with these
materials and without gypsum wallboard could be incorrectly restricted as if
they had gypsum wallboard, which is not allowed in Design Categories E and F
and less than 35 feet in Category D.
1. Shearline Force Distribution
a)
Rigid Diaphragm
Results in Log File (Bug 1803)
Refer to the Output section of this list for extensive changes made to
the detailed log file output for Rigid Diaphragm distribution.
b)
Shearlines and
Walls with no Capacity (Features 48, 89)
The ability to
now have walls composed entirely of gypsum wallboard combined with the Ignore gypsum … Design Setting, creates
the possibility of shear walls and shearlines with no capacity. The program
treats these as if they were composed entirely of non-shearwalls, and
distributes no load to these walls and lines.
The following
problems were addressed, pertaining to the "Drag strut forces based on shearwall capacity" design
setting. This setting was added for
version 7.1 of the software.
a)
Shearwall
Capacity Used for Drag Strut Forces (Bug 1897)
When using applied force in the calculations, the program takes the
difference of cumulative shear flow at top and design shear at the bottom of
the wall. When using shear wall capacity, the program was using the capacity in
place of design shear, thus summing capacities for different walls in the line.
We replaced this approach with one that uses the cumulative shear
forces, as before, and then factors them with the ratio of design shear to
shear capacity for the wall that contains the drag strut. Note that this ratio
is actually the same for all walls on the line, because shear is distributed to
wall segments according to wall capacity.
b) Shear Flow in Drag Strut Force Calculation (Bug 1901)
When shear capacity
was used in place of the design shear, the shear flow transmitted from upper
diaphragm to top of shear wall that was used in the drag strut calculations for
this setting was always zero. This was
creating drag strut forces that were too large, or sometimes to not be created
when they should be.
c)
Differing Drag
Strut Forces in Opposing Directions (Bug 2016)
The drag strut forces
reported in the Drag Strut and Hold-down
table were randomly taken from either the east-west or west-east force direction
(similarly for N->S and S->N), so that when forces from these directions
differ, only half the force values are reported. The reported forces could be a
confusing mixture of forces from each direction that did not correspond to any
elevation view diagram. Note that because of hold-down configuration rules, it
is often the case that the drags strut forces are different in each direction.
This problem has been
corrected by outputting the drag strut value for both force directions for each
drag strut location.
d)
Walls with No
Capacity (Feature 49,89)
The ability to
now have walls composed entirely of gypsum wallboard combined with the Ignore gypsum … Design Setting, creates
the possibility of shear walls with no capacity. The program omits these walls in the drag
strut force calculations.
e)
Irregularities
Notes for Drag Strut Provisions (Bug 2021)
Refer to the section
on section on Seismic Load Generation above for an explanation of the Seismic
Irregularity notes and warnings that appear for NBCC 4.1.8.15-2 pertaining to
Irregularities 3, 4, and 5 affecting drag strut force calculations.
a)
Default Hold-down
Offset (Change 39)
The “factory” default
hold-down offset has been reduced from 150 mm to 75 mm, in recognition that the
chord force is actually transferred to the hold-down connection at the centre
of the chord, not where the hold-down bolt goes through the floor joist.
b)
Walls with No
Capacity (Feature 49,89)
The ability to
now have walls composed entirely of gypsum wallboard combined with the Ignore gypsum … Design Setting, creates
the possibility of shearwalls and with no capacity. The program recognizes these walls and does
not create hold-down forces for them.
c)
Irregularities
Notes for Hold-down Provisions (Bug 2021)
Refer to the section
on section on Seismic Load Generation above for an explanation of the Seismic
Irregularity notes and warnings that appear for NBCC 4.1.8.15-2 pertaining to
Irregularities 3, 4, and 5 affecting hold-down force calculations.
a) Gypsum on Exterior Wall (Feature 89)
It is now possible to have
gypsum wallboard on the exterior of the of a perimeter wall. The program does
not perform C&C wind design in this case, and issues a warning to that
effect in the Design Results output.
b) No Materials on Exterior Wall (Feature 49)
It is now possible to
specify None as the material on the
exterior of the of a perimeter wall. The program does not perform C&C wind
design in this case, and issues a warning to that effect in the Design Results
output
c) Primary Design Surface (Features 49, 89)
Previously, the exterior
surface of a perimeter wall, and the side designated as Side 1 of an interior
partition, was designated as the primary design surface in the case that
materials were different on either side. You were able to designate some parameters
for that surface as unknown, and the program would design for these values.
Now, the side of the wall
that has structural (plywood, fibreboard, OSB) materials is designated as the
primary side, and the side with gypsum or no materials is the non-designed
side. If both sides have structural materials, then the primary side is the
exterior of perimeter walls and Side 1 of interior walls, as before.
d) OSB Construction Sheathing (Change 45)
The program was internally omitting OSB
Construction from the list of wood-based materials, so that the program may
in some cases not have accurately imposed the restrictions on material strength
due to hold-down/anchorage restrictions in CSA O86 9.4.5.5.
2. Maximum Gypsum Wallboard Contribution (Feature
131)
The program now
includes an improved implementation of CSA O86 Table 9.5.4 which specifies the
maximum gypsum contribution on any level of the structure, in each direction.
a)
Check for Total
Capacity vs. Force
The program checks on
each level and in each direction, that the total capacity of all walls on that
level is at least as great as the total force. In this case, at least some of
the shear walls will have failed, and the program does not go on to check for
minimum wood capacity or maximum gypsum capacity as indicated in the following
sections.
b)
Check for Minimum
Wood Capacity
After shear wall
design, the program checks that there is sufficient capacity from wood panels in
the designed shear walls to satisfy the requirements of CSA O86 Table 9.5.4 if
all force were to be distributed to those wood panels. It does so independently
on each level and for each force direction, for both wind and seismic design.
If the wood capacity
is not at least 100% minus the allowable GWB percentage, the program regards
this as a design failure and indicates so via a message box on the screen, and
via failure notes under the Shear Design
table and the new Gypsum Wallboard
Percentage table, and via “FAILED” showing on the walls of that level on
elevation view.
Refer also to the
section on Output below for a full description of the Gypsum Wallboard Percentage table.
c)
Check for Maximum
Gypsum Capacity
After shear wall
design, the program checks if the percentage of total shear force taken by
gypsum wallboard exceeds the maximum in CSA O86 Table 9.5.4. In determining the
shear force taken by GWB, it assumes that the force into composite wood/gypsum
shear walls is distributed proportionally to material capacity. It does so independently on each level and
for each force direction, for both wind and seismic design.
If there is greater
than the maximum allowable gypsum contribution, the program offers you the
choice of ignoring gypsum wallboard contribution in design and redesigning, or
proceeding with the design anyway. For seismic design, it also offers you the
opportunity to regenerate loads on the structure with the revised response
modification R value appropriate to all-wood systems.
If you choose not to redesign, the program
presents a warning under the Shear Design
table and the new Gypsum Wallboard
Percentage table indicating that you must ensure that sufficient shear
force is distributed to wooden panels to avoid excess gypsum contribution.
Refer also to the
section on Output below for a full description of the Gypsum Wallboard Percentage table.
d)
Ignore Gypsum
Wallboard in Design
If you have selected
the “Ignore gypsum wallboard design
setting for either or both of wind and seismic design, the program does not do
the abovementioned Check for Minimum Wood Capacity or Check for Maximum Gypsum
Capacity for that design case, instead putting a note explaining this in place
of the Gypsum Wallboard Percentage table.
‘
On all storeys
greater than 3.6m in height, the gypsum contribution to shear resistance is
automatically ignored in load distribution and design to comply with to Table 9.5.4 Note 2. This applies to
both wind and seismic design. This is done regardless of the design setting
that disables gypsum contribution for all levels. The program indicates in the
notes to the Shear Results table and the Gypsum
Wallboard Percentage table that GWB has been ignored for this reason.
f)
Five- and Six-storey
Structures
For five- and six-storey structures, all gypsum contribution to shear
resistance is automatically ignored in load distribution and design, on all
levels of the structure, because CSA O86 Table 9.5.4 does not yet include 5-
and 6- storey structures. The program indicates in the notes to the Shear Results table and in a note that
appears in place of the Gypsum Wallboard
Percentage table that GWB has been ignored for this reason.
Note that there are proposed changes to the BC
Building Code that allow gypsum wallboard on 5- and 6- storey structures, and
these will be implemented in the software at a future date. Refer to BC
Building Code Branch at: http://www.housing.gov.bc.ca/building/wood_frame/index.htm and
APEGBC Guidelines at http://www.apeg.bc.ca/ppractice/documents/ppguidelines/5and6StoreyWoodFrameBulletin.pdf
Please note that this
implementation replaces a previous one that was in Shearwalls 2002, but was
dropped for version 7.0 because it was deemed inadequate. The previous
implementation divided the sum of the capacity of the gypsum wall board panels
on a building level by the sum of the capacity of all walls the level, and
compared with the limits in 9.5.4. This implementation did not take into
account directionality and therefore did not include the Jhd factor in the total capacity.
In this
implementation, the program merely sent a message to the screen indicating that
there was excessive gypsum capacity. As it was not possible in this version to
have walls composed solely of gypsum wallboard, this message rarely appeared.
a)
Service Condition
Factor Ksf for Shear Design (Change 22)
The moisture condition Ksf
Factor is now applied to the shear design, according to CSA O86 9.4.2.
The in-service and fabrication service conditions as input in the Design Settings are applied according to
CSA O86 Table 10.2.1.5 for nails.
b)
Optimization of
Design (arising from Feature 131)
Certain steps were
taken to speed up the shear design routine by eliminating redundant
calculations.
c) OSB Construction Sheathing (Change 45)
d)
The program was internally omitting OSB
Construction from the list of wood-based materials, so that the program may
in some cases have determined that the shearwall had zero capacity if it had
only OSB Construction materials and “Ignore gypsum” was set in the Design Settings. It may also have
misapplied height-to-width ratio restrictions in this case.
4. Component and Cladding (C&C) Wind Design
a) Design for Exterior Shearwalls with No
C&C Resistance (Change 36)
As it is now possible
for there to be no materials, or non-structural (gypsum) materials on the
exterior walls, the program recognizes this situation and outputs a warning in
the C&C Design Table. Refer to the Output section of this list for more
details.
D: Input and Program Operation
a) Design Codes in About Box (Change 41)
The program now indicates the design codes and standards implemented in
the program: CSA O86-01, including 2003 Update and 2005 Supplement, and NBCC
2005.
b) Welcome Dialog Via Help Menu (Change 44)
The Welcome box can now be accessed from the Help menu, so that you do
not have to restart the program to access the information in this box.
c) Building Codes Box (Feature 131)
A Building Codes dialog box
has been added, accessed via a button in Welcome
dialog. This dialog
- Repeats the information in the Welcome dialog regarding design codes implemented by the program
- Indicates that Shearwalls does not take into account shearwall deflection or wood shrinkage, nor does it detect certain irregularities
- Indicates which Mid-rise provisions for 5- and 6-storey structures are included and which are not.
- Directs you to http://www.apeg.bc.ca/ppractice/documents/ppguidelines/5and6StoreyWoodFrameBulletin.pdf for more information about Mid-rise structures.
a) Wall Height Check upon Return to Structure
View (Bug 1787)
The program did not perform
the check on allowable wall height input in Structure
input form, if you had returned to that form from a later view in the sequence.
Therefore, it was possible to accidentally enter a zero height wall, which
would cause the program to crash. Now the program checks that a legitimate wall
height is input whenever the Structure
view is exited.
b) Five- and Six Storey Structures (Feature 131)
Upon adding fifth building
level, the program issues an on-screen message informing that only some of the
provisions for 5-and 6-storey structures in the British Columbia Building Code
are implemented in the program, directing you to the Building Codes box,
accessed from the Welcome dialog, to find out which are implemented. The
message also refers you to the BC Building Code Branch at http://www.housing.gov.bc.ca/building/wood_frame/index.htm and
Association of Professional Engineers and Geoscientists of British Columbia
(APEGBC) Guidelines at http://www.apeg.bc.ca/ppractice/documents/ppguidelines/5and6StoreyWoodFrameBulletin.pdf
a) Wall Surface Input Mechanism (Change 32,
Feature 49)
- The drop list for selecting Wall Surface in the Wall Input view has been replaced by two tabs called Interior side and Exterior side ( Side 1 and Side 2 for interior partitions). These tabs contain all the input fields that previously were visible when Exterior and Interior were chosen from the drop list.
- The choice Both sides same has been replaced by a checkbox that causes the input to be compressed into one tab called Both sides. As before, the materials that are displayed are the ones that were on the exterior side (or Side 1) before the box is checked.
-
The choice Exterior
only has been removed, as it can be achieved by specifying None for the interior side of the wall.
- Previously, the material choices for interior walls were the same as those for exterior walls, and assumed that one surface would not have gypsum materials. Now, the program provides the entire list of choices for both sides of interior walls, to allow for the common situation of gypsum on both sides. (Bug 1891)
- The sheathing materials None and GWB Type X (gypsum wallboard) are now available on the exterior surfaces of exterior walls. Previously these surfaces had to have wooden sheathing (Feature 89)
- The choice None has been added for the exterior side, to allow for no structural materials on the outside of a structure with structural materials on the inside surface. The program does not include the selection None if None is selected on the other side of the wall, in other words, shear walls must have sheathing on at least one side. (Feature 49)
c) Side with Unknowns (Features 49, 89)
Previously, the exterior side of perimeter walls and Side 1 of interior partitions could have
unknown parameters for sheathing thickness, nail size, and nail spacing. Now,
the side of the wall that has structural (plywood and OSB) materials can have
unknowns, and the side with gypsum or no materials does not have them. If both
sides have structural materials, then the program reverts to its previous
behaviour.
d) Nomenclature Changes and Reorganisation
- The label Wall segment referring to the geometry of a selected shear wall has been changed to Shearwall, as the data refer to the entire shear wall, not an individual segment between openings.(Change 34)
- The sheathing material name Gypsum X has been changed to GWB Type X. The abbreviated form that appears in output reports is GWB. (Change 16)
- The label Relative rigidity has been changed to Relative rigidity per unit length. (Change 20)
- The Design Group(s) text field indicating what design groups have been created for the selected wall has been moved from near the top to the bottom of the input form. (Change 35)
e) Multiple Wall Selection Problems
The following problems have been corrected:
- Both Sides Same (Bug 1994) - In the wall input dialog, after more than one wall is selected, and then "Both Sides the Same" is selected, the individual walls are often not designated as "both sides the same" when selected, and some of the fields have the original value in them, that is, were not properly updated for all of the walls selected.
- Gypsum Wallboard (Bug 1993) - After selecting more than one wall, and selecting Gypsum X (now GWB Type X) on the interior wall surface in the wall input dialog, the fastener type appeared as a blank. If left blank, he selected GWB materials are not included in the design capacity of the wall. However, selecting a fastener type allowed for design.
f) Incorrect Parameter Message for OSB (Change
47)
Under certain
restricted circumstances, when trying to create a wall a message appears
sayings “Incorrect parameter".
These circumstances are
- Interior wall
- OSB materials
- hold-down configuration other than “All Segments”
- previous sheathing thickness greater than 12 mm
- anchorage design setting is set to “restrict materials” or “restrict materials but override when unknown”.
a) Crash on Standard Wall Cancel (Bug 1889)
When editing a
Standard Wall, then pressing Cancel, Shearwalls would crash. This happened
only for existing projects that are reopened, not for new files. This has been
fixed.
b) Standard Wall Name Label (Change 40)
The label "Name" was mistakenly
removed from the Standard Wall input form for version 7.1. It has been
restored.
c)
Standard Wall
Dropdown Box Length (Change 14)
The dropdown box for
Standard walls has been lengthened, so that you do not think that only one
standard wall can be created because that is all that is shown without
scrolling.
d)
Selection of
Standard Walls for C&C Design (Change 37)
As it is now possible
to have non-structural materials on exterior surfaces, and because all walls
should be available for seismic design, the program no longer issues a message
and prevents you from selecting a standard wall for the exterior of the building
that cannot withstand wind C&C loads.
a)
Partial Wall Load
Input (Bug 1911)
When adding a line
load in the load Input dialog when “Selected Wall” is set as the “Apply to..”
selection, then changing the locations
such that they are less than the full extent of the wall, the load was still being
added to the full length of the selected wall. This has been corrected such
that the load has the reduced extent entered.
a)
Moisture
Conditions (Change 22)
- In the Design Settings, the group heading Nail Withdrawal Conditions has been renamed to Moisture conditions for Ksf, as they are now applied to shear design as well as C&C design.
- The choices in the Fabrication box have been changed from "Wet", "Dry" to "Unseasoned", "Seasoned" to correspond with CSA O86 terminology. The In-service choices have not changed.
b) Hold-down Force Setting Persistence (Change 24)
The Design setting Holddown forces based on Shearwall capacity was not saved when the
project file was saved, so it would be reset to the default value, Holddown forces based on Applied loads
when projects were re-opened.
c) Design Settings in Data Bar (Change 30)
The "Design…" button on the Data bar has
been renamed to "Settings…",
to avoid confusion with the Design
button in the toolbar which causes a design to be run.
d) Immediate Effect of Default Settings
(Changes 25, 26)
In the Default Settings page:
- The explanation has been revised to indicate that only Roof geometry settings depend on exiting Structure View.
- An asterisk has been added the Holddown offset to indicate that it has immediate effect.
e) Note in Design Settings (Change 21)
The word “However” and the design code name “NBCC” has been added to the
note at the bottom of the Design Settings box indicating seismic discontinuity
exception to the use of Applied Force for hold-down and drag strut
calculations.
a) Legends and Notes (Change 9)
- The Design Results have been updated so that the notes under the tables are in plain face to distinguish them from the legends, which are in italic.
- Those notes that are considered warnings that indicate design failure are now output in red and are the last notes printed.
- A heading of 'Legend:' now precedes the legends and the program now consistently places the heading "Notes" before notes.
b)
Text-based (.wsr) Output Files
(Bug 1886)
The program no longer
outputs Shearwalls text-based results files (.wsr), as they have not been
maintained since the enhanced output was introduced for Shearwalls 2004 USA.
The extension .wsr
has been removed from the filename on the header of the printed file output,
which in fact can be output as .rtf or .pdf.
a)
Moisture
Conditions (Change 22)
In the Design Settings, the group heading
"Nail Withdrawal Conditions " has been renamed to "Service
Conditions", as they are now applied to shear design as well as C&C
design.
The items under Fabrication have been changed from
"Wet", "Dry" to "Unseasoned",
"Seasoned" to correspond with CSA O86 terminology.
3. Material and Structural Data
a)
Species Factor Jsp
Output for Gypsum Surfaces (Bug 1992)
In the Materials by
Wall Group output table, the species factor Jsp shown for an interior Gypsum X
surface is that of the external (non-gypsum) surface, however, Jsp
does not apply to gypsum wall surfaces according to CSA O86 9.5.1. For gypsum
materials, which can now appear on either surface, that the Jsp
value does not exist is now indicated by a “-“.
b)
Gypsum Wallboard
Notes (Bug 1904, Feature 131)
The following notes
are now output under the Materials by
Wall Group for gypsum wallboard materials.
When gypsum is
present, a note has been placed under the Materials table indicating that a
balanced distribution of gypsum is needed to comply with CSA O86 9.5.4 (2).
c)
Imperial Joist
Depth in Storey Information Table (Bug 2019)
When Imperial is the
unit system, the joist depths in the were given as 25.4 times the depth in
inches, that is, converted to millimetres, but the label still read inches. The
program now outputs values in inches.
d)
Jsp in
Materials Table for GWB*
In the Materials
table, a "-" is now output as species factor for gypsum wallboard, as
Jsp does not apply to GWB.
a) Gypsum Wallboard Limitation Warnings and
Notes (Feature 131)
The program now indicates under the Shear Design table if there are
failures or concerns arising from CSA
O86 9.5.4 and Table 9.5.4. It does so separately for the wind design and shear
design tables, as follows:
- There is a red failure message if on any level in any direction there is insufficient capacity from wood panels to resist the remaining storey force after the maximum gypsum contribution from Table 9.5.4 is taken away.
- There is a red warning message if the percentage of storey shear resisted by gypsum is greater than the maximum allowed by Table 9.5.4.
- If at least one storey is greater than 3.6 m, a note indicates that the gypsum wallboard contribution to shear resistance is ignored for all walls on that storey.
- When the structure has more than four storeys, a note indicates that the gypsum wallboard contribution to shear resistance is ignored for all walls in the structure for that reason.
- When gypsum wallboard is present, a note indicates a balanced distribution of gypsum is needed to comply with CSA O86 9.5.4 (2).
- If some shear wall sides have zero capacity because you have disabled the gypsum contribution in the design settings, a note indicates this.
Refer to the section on Maximum
Gypsum Wallboard Contribution in the Engineering Design Changes in this
list for more information.
b)
Service Factor Ksf
in Legend (Change 23)
The legend in the Shear Design table now gives the service
factor Ksf that is now used in design followed by a description
(e.g. dry seasoned. Previously it
said "Ksf = 1(dry)” at all times..
5. Components and
Cladding Table
a)
Components and
Cladding Table Legend (Change 17,18)
Legend under
Component and Cladding (C&C) table in Design Results has been elaborated on
further. It now gives Commentary numbers and figures from the NBCC Structural
commentaries, and explains the combination of interior and exterior pressure
co-efficients for each method. It also
refers to table I-8 instead of I-7 from the 1995 NBCC.
b)
Exterior
Shearwalls with No C&C Resistance (Change 36)
As it is now possible
for there to be no materials, or non-structural (gypsum) materials on the
exterior walls, for such a shearline, a double asterisk (**) is output as the response ratio in the
C&C results table, indicating the following beneath the table: **WARNING - No exterior sheathing material
or sheathing has no C&C capacity.
6. Drag Strut and
Hold-down Table
a)
Drag Strut Forces
in Opposing Directions
The drag strut forces
reported in the Drag Strut and Hold-down table are randomly taken from either
the east-west or west-east direction (similarly for N->S and S->N), so
that when forces from these directions differ, only half the force values are
reported. The has two columns headed with arrows were used to show the
direction the drag struts forces themselves were pointing, not the force direction
on the shearline. They are now used to show the drag strut force for loading in
each direction for each drag strut location.
7. Seismic Information and
Seismic Irregularities Table
a)
Header in the
Seismic Information Table (Bug 1907)
In version 7.1 of the
software only, the Column header 'Length
of SFRS, E-W N-S ' was not output in the Seismic Information table. It has
been restored.
b)
Irregularities
Notes for Drag Strut and Hold-down Capacity Provisions (Bug 2021)
Changes were made to the notes regarding the
NBCC 4.1.8.15-2 provision for Irregularities 4, 5, and 6. Refer to the section
on Seismic Load Generation for more information.
8. Gypsum Wallboard
Table (Feature 131)
Separate tables are now output for each design case (rigid, flexible,
wind, seismic) giving the relevant data to implement the restrictions on gypsum
wallboard contribution in CSA O8 Table 9.5.4
In the following
circumstances, no table is output and an explanatory note appears instead:
- For five- and six storey structures, because Table 9.5.4 does not yet include these structures.
- If you have chosen to ignore gypsum wallboard contribution to design shear wall resistance in the Design Settings.
The table outputs the
following data for each storey and each direction of force:
-
Storey
number
- Maximum GWB Percentage – Maximum gypsum wallboard contribution allowed from Table 9.5.4, or if the storey is greater than 3.6m in height, zero.
- GWB Capacity – Total capacity of all gypsum wallboard on storey, regardless of distribution of forces to the wall segments
- Wood Capacity – Total capacity of all plywood and OSB panels on shearline, regardless of distribution of forces to the wall segments.
- Total Force – Sum of all factored shearline forces on that level in that direction
- Wood Capacity % - The total wood capacity on the line as a percentage of the total force applied to the line. This value indicates whether sufficient wood panels are available to resist the force. The program considers it a failure if this value is less than 100% minus the allowable gypsum contribution. In that case a
- Force Resisted by GWB – The percentage of shear force that is actually resisted by GWB panels on the shearline, assuming that force into composite walls is distributed according to relative capacity of the wood and gypsum sides.
- % Force Resisted by GWB – This is the force resisted by GWB as a percentage of the total factored shearline force. If this value is greater than the maximum allowed by Table 9.5.4, the program issues a warning that you must redistribute the excess gypsum force to the wood shearwalls.
A legend appears at
the bottom of the table explaining the above data.
d)
Insufficient
Total Resistance Failure
If there is
insufficient total resistance on a particular storey and direction to resist
the total force, then two exclamation marks (!!) appear in the % gypsum column
in place of the data, and a red failure note starting with !! appears below the
table. In this case, at least some of
the walls on the shearline will have failed, and there is little point in
checking the % gypsum contribution.
e)
Insufficient Wood
Capacity Failure
If there is
insufficient capacity from wood panels available to resist the remaining storey
force after the maximum gypsum contribution from Table 9.5.4 is taken away,
then one exclamation mark (!) appears beside the Wood Capacity % data for that storey and direction. A red failure
note starting with ! appears below the table.
f)
Excessive Gypsum
Wallboard Contribution Warning
A note appears saying
that the If the percentage of storey shear resisted by gypsum wallboard on a
particular storey and direction is greater than the maximum allowed by Table
9.5.4, then indicating that you must modify
the design to ensure sufficient shear force is redistributed to wooden panels
to avoid excess gypsum contribution.
- If at least one storey is greater than 3.6 m, a note indicates that the gypsum wallboard contribution to shear resistance is ignored for all walls on that storey.
- A note is always output indicating that a balanced distribution of gypsum wallboard is needed to comply with CSA O86 9.5.4 (2).
a)
Gypsum Wallboard
Failure (Feature 131)
If for any level shown in elevation view in the
selected direction there is insufficient
is sufficient capacity from wood panels to resist the remaining storey force
after the maximum gypsum contribution from Table 9.5.4 is taken away, the
progam
- Indicates with in large bold letters “FAILED” on all shearwalls on the line for the failing levels
- Prints separate failure notes for the cases that just one level or several levels are displayed.
Note that the program
does not in elevation view indicate the warning for excessive gypsum resistance
to shear force that appears in the Gypsum
Wallboard Percentage table and in the Shear
results table. This is because this situation depends on distribution of
shear force, and the line selected may not be one in which force is distributed
to gypsum wallboard.
10. Rigid Diaphragm Analysis in Log File (Bug 1803)
The Rigid Diaphragm
Analysis section of Log File has been modified in the following ways:
a)
Explanatory Line
for Rigidity Selection
A line has been added
at the top of the section that indicates the Shearwall Rigidity selection in
the Design Settings, and to explain what rigidity units are employed with each
selection. For “Shearwall capacity”, force units are used (kN, lbs or kps), for
“Equal rigidities” (per unit length), length units are used (m or ft), and if
it is “Manual input of relative rigidity”, then they are treated as
dimensionless numbers.
A consistent set of
symbols has been introduced, and equations given for all symbols, so that the
source of all output data can be traced. Where applicable, design code
references also added. Note that in many cases a symbol is used before the
place in the output that the symbol is defined by its own equation.
- Unit Indicators
The Indicator of length and force units has been removed from the
header, and instead, the units are placed on all individual items in the
report. The formatting of the units has changed slightly, in that the units are
placed in brackets after the label for an item, rather than after the last
value output for that item
- Force Units Employed
Previously, only kN were used, even when imperial units were selected in
the Format Settings. Now for the
Imperial units selection in the Format Settings, either lbs, kips, or kN are
used according to the Force format setting.
Note that other portions of the log file continue to be output in metric
units even when for the imperial format setting selection.
- The output is now consistent in its use of hyphens (-) and colons (:).
- The length of the dashed line has been shortened, and all output is constrained to remain within that line, so that it prints on one page in Notepad with a 9 font.
- For to the initial section of data that is output for the X-direction and the Y-direction on the same line, the previously ragged data has been placed in two columns, for the X-direction and Y-direction, with the letters x and y appended to the symbols, e.g. Jx and Jy for Torsional Rigidity J. These symbols are later referred to in the separate results for the E-W and N-S directions, making it clear which is used for which direction of force.
The word “of” has
been added to “Center of Rigidity”, which can now be m or ft, along with symbol
Cr and equation.
A line for building
dimension D, perpendicular to the force direction, has been added, as this is
used in the eccentricity calculation. .
-
The output
“Acc Eccentricity” has been removed for wind design, which does not impose an
additional accidental eccentricity. For
seismic design, it is now on its own line, with “acc” fully spelled out,
equation and units shown, symbol ea.
-
A note has
been added to the end of this section of output indicating the design code
reference for eccentricity.
The symbol Kt, equation, and units employed
have been added to the Total Rigidity line
-
Previously
the program was indicating that this value was in metres for all selections of
the “Shearwall rigidity” Design Setting, however the value for the “Rigidity
based on capacity” setting was in fact in kN, as it was the sum of all
shearwall capacities. The program now indicates it is kN, lbs, or kips for that
setting, depending on what unit system is in use.
-
Length
units continue to be used for the “Equal rigidity” (per unit length)” setting,
as this value is just the sum of shearwall lengths.
-
For the
“Manual input” setting, this value is
the shearwall length multiplied by the relative rigidity input in wall view, so
no unit is used.
-
Torsional
rigidity has been placed on its own line. The symbol J, equation, and units
employed have been added to the Torsional Rigidity label.
-
Previously
the program was indicating that this value was in m^3 for all selections of the
“Shearwall rigidity” Design Setting, however the value for the “Rigidity based
on capacity” setting was in fact in kN-m^2.
The program now indicates it is kN-m^2., lbs-ft^2, or kips-ft^2 for that
setting, depending on what unit system is in use
-
The value
for the “Equal rigidity” (per unit length)” setting uses shearwall length to
approximate rigidity, so the output is in m^3 or ft3.
-
For the
“Manual input” setting, the rigidity component is the shearwall length
multiplied by the relative rigidity input in wall view, so no unit is
used.
-
If the
value to be output exceeds 1,000,000, then it is expressed in scientific
notation, with 4 decimal places shown. Otherwise, it is shown to one decimal
place for metric output and none for imperial.
Symbol F added.
Symbol Cl added
For all torsional
load cases (seismic [and all-heights wind]), a line has been added giving the
torsional eccentricity et = Cl-Cr (center of load minus center of rigidity).
-
Torsions
are now output on their own line, with symbol T and units (lbs-ft, kips-ft, or
kN-m). They are no longer output in scientific notation.
-
Separate
equations have been added for each load case showing whether a torsional
eccentricity due of Cl – Cr, an accidental eccentricity, or both, are
used. If it is a non-torsional load case
(low rise wind), torsions T = 0 are shown along with an explanation giving
design code reference.
A section has been
added giving the equations used for the torsional, direct, and total shearline
forces shown in the shearline table below.
-
In the
heading, the torsional load cases used to read “+10 Dnx -10Dnx” These were
missing a % sign, but the line has been reformatted and these symbols removed.
It now shows torsional shearline forces as Fti-, Fti+, and the resultant Fti,
with the definition of the Fti’s in terms of Dnx shown in the equations above.
Note that the resultant Fti column has also been shifted in the table.
-
A column
has been added for the distance li from the Center of Rigidity Cr to the
shearline, as that is needed in the calculations of shearline forces.
-
The table
headings have been reworded slightly and now include the symbol for each item
-
The unit
shown for Rigidity was previously always
“m”, even though though for the
“Rigidity based on capacity”
Design Setting “Rigidity based on capacity” the value was in fact kN. Now the value shown is kN, lbs or kips for
that design setting, m or ft for the
“Equal rigidities” ( per unit length) setting, and no unit for the
“Manual input” setting.
p)
Output in Absence
of Wind or Seismic Loading (Change 15)
In the Rigid
Diaphragm Analysis section of the Log File, some information for wind or for
seismic analysis was being output even when there were no loads of that type on
the structure. The title for that
design type and the lines pertaining to rigidity and eccentricity were output,
but not the shearline table below. This occurred only when the Shearwalls
rigidity setting selection is not “'Use shearwalls capacity …”. The program now
omits all wind analysis when there are no wind loads, and similarly for seismic
loads.
q)
Repetition of
Rigid Diaphragm Log File Output (Bug 1878)
The rigid diaphragm
section of the log file results were often repeated twice, one for each
iteration of the design process. Only the final iteration is now output.
1. Windows Metafile Example (Bug 1966)
The windows metafile,
'example.wmf' that is referenced in the Shearwalls Tutorial of the User Guide
has been restored to the installation. It had been removed unnecessarily along
with some obsolete sample project files.
Shearwalls 7.1 –
July 28, 2008 - Design Office 7, Service Release 1
This is a free
service release update to address issues submitted by our users since the
release of version 7.0 on December 21, 2007 and also to implement non-critical
bug fixes and small improvements which previously had been deferred. The links below lead to descriptions of the changes made to
Shearwalls for Version 7.1.
1. Crash on Design of Short Shearwalls (Bug 1839)
1. Pj and Ptop Values in Calculation of
Jhd Factor (Bug 1841)
2. Rj Value in Calculation of Jhd Factor
(Bug 1842)
3. C&C Results in Elevation View for Non-Shearwalls (Bug
1832)
4. C&C Table Legend in Design Results
5. Alternating Wall Designs (Bug 1840)
6. Relative Rigidity for Standard Walls (Feature 175)
7. Seismic Allowable Shear Capacity Zero (Bug 1652)
1. Shear Force Distribution for Walls Designed with High
Capacity
2. Vertical Loads on Shearlines with Non-shearwall Segments
(Bug 1682)
3. Drag Struts for non-FHS Segments (Bug 1683)
4. Lack of Warning for Rigid Non-Design (Bug 1759)
5. Torsional Load Case Heading in Log File (Bug 1853)
C: Load Generation and Display
1. Wind Load Generation on Multiply-joined Roof Blocks (Bug
1758)
2. Unfactored Loads in Elevation View Legend
3. C&C Loads in Elevation View
4. Ce vs Ce* in Log file (Bug 1224)
5. Seismic Load Magnitude Formatting (Bug 1256)
3. Changing Structure Ceiling Depth (Bug 1728)
4. Upward Extending of Non-Shear Walls (Bug 1779)
1. Meta File and Project File in Separate or Renamed Folders
(Bug 1740)
2. Log Filename Persistence (Bug 1851)
3. Rigid Distribution Information Clearing in Log File
(Bug 1852)
4. Truncated Elevation View Material Information and Legend
(Change 6)
5. Unreadable Design Results with Combination Printers (Bug
1790)
6. OCX Files in Installation (Change 7)
7. Immediate Effect of Default Settings (Bug 1693)
1. Crash on Design of Short Shearwalls (Bug 1839)
Performing a design on a structure that contains a shearwall that does not contain any shearwall segments that meet the minimum height-to-width restriction was causing the program to crash. This has been rectified.
1. Pj and Ptop Values in Calculation of Jhd
Factor (Bug 1841)
When both dead loads and "dead wall" loads are present on the same wall, the program was not separating the dead and dead wall loads when calculating uplift restraint forces Pij and Ptop in CSA O86 9.4.5.2 and 9.4.5.3, causing these values and therefore hold-down effect factor Jhd to be incorrect.
2. Rj Value in Calculation of Jhd Factor (Bug 1842)
In the calculation of the
overturning force Rj used in calculating uplift restraint forces Pt and Pj in O86 9.4.5.2 was incorrectly
subtracting the 150mm hold-down offset that was introduced in version 7 from
the segment length L. This caused the hold-down effect factor Jhd to
be slightly smaller than it should be on all levels except the top level.
3. C&C Results in Elevation View for Non-Shearwalls (Bug 1832)
When
a non-shearwall is loaded with Components and Cladding (C&C) wind loads, in
Elevation View the program was
displaying design parameters as unknown, and both the capacity and load as
zero. In the Design Results, the
materials and the C&C design results are correctly displayed. Both areas of the program
display now display the correct C&C design results.
4. C&C Table Legend in Design Results
Legend under Component and Cladding (C&C) table in Design Results has been clarified. It now indicates that forces are factored, and includes nail withdrawal design code clause O86 10.9.4.
5. Alternating Wall Designs (Bug 1840)
Running a design on a structure with walls loaded in only one direction, the program was generating two sets of designed materials, which would alternate each time design was invoked.
6. Relative Rigidity for Standard Walls (Feature 175)
Added relative rigidity field to standard wall definition so that you can create multiple walls with same rigidity. Only active if the setting Manual input of shearwall rigidity is checked. It defaults to 1.0 for new standard walls.
7. Seismic Allowable Shear Capacity Zero (Bug 1652)
Saving prior to designing a
structure with narrow wall segments caused the seismic allowable shear capacity
to be calculated as zero in Elevation
View and the Design Results
report. However, running "Design" immediately after opening the project yields a valid non-zero seismic
allowable shear capacity.
1. Shear Force Distribution for Walls Designed with High Capacity
Under certain circumstances, the forces distributed to shearwall segments were based on Jhd values calculated for anchorages, even though the design required hold-downs. This occurred when the wall had unknown design parameters, and the wall selected by Shearwalls for design had a shear strength greater than 10.3 kN/m, requiring hold-downs due to CSA 086-01 9.4.5.5(a).
2. Vertical Loads on Shearlines with Non-shearwall Segments (Bug 1682)
Manually input dead and uplift loads on shear lines are now included on non-shearwall segments, and distributed to the floors below via the same hold-down force mechanism as for shearwalls. Previously no loads were created for these portions of the walls, and these loads were not properly tracked down the structure.
3. Drag Struts for non-FHS Segments (Bug 1683)
Drag
strut force calculations were incorrectly adding a force due to non full height
sheathing (non-FHS) segments to the adjacent force from an adjacent FHS when
the non-FHS segment was at the end of a wall, creating higher drag strut forces than the correct
ones, and creating an additional drag strut force location.
4. Lack of Warning for Rigid Non-Design (Bug 1759)
When
the program does not have sufficient loaded shearlines using the flexible
distribution (I.e. two per direction), so that the program cannot perform rigid
distribution, a message box now warns the user of this situation.
5. Torsional Load Case Heading in Log File (Bug 1853)
The heading in the log file for the torsional load cases for rigid diaphragm analysis given by NBCC 2005 4.1.8.11 10) i and ii, was mistakenly showing the load cases from the 1995 NBC. It has been corrected to show plus or minus 10% of the building width, as follows:
Torsion Load Cases
+10%
Dnx -10% Dnx
C: Load Generation and Display
1. Wind Load Generation on Multiply-joined Roof Blocks (Bug 1758)
When three blocks were aligned in one direction, and when the "Exclude roof portion cover by other roof" option is checked, for the ASCE-7 medium rise method, loads were not displayed on the screen nor did they contribute to design loads on the structure.
2. Unfactored Loads in Elevation View Legend
Lines were added in the Elevation View legend to show symbols for wind uplift and dead loads, also indicating that these loads are unfactored.
3. C&C Loads in Elevation View
Changed the description for C&C loads to the right of the walls in elevation view from "C & C" to "Unfactored C&C Load"
4. Ce vs Ce* in Log file (Bug 1224)
When topographic factor is present, the exposure factor Ce factor is now presented in the log file as C*, as per the NBCC design code nomenclature.
5. Seismic Load Magnitude Formatting (Bug 1256)
In the Seismic load table of the results output, the program now outputs 2 decimal places precision for all output.
It is now possible to select all walls while in the Wall Action in plan view for editing and moving, via a menu item in the Edit menu. You can also use Ctrl-A keystroke to do the same thing.
It is now possible to move the entire structure, while the Wall action, by
a) being in the Wall action in plan view
b) using the Select All Command
c) pressing the Shift key on the keyboard
d) also depressing the left mouse button
e) selecting a point in plan view and moving the mouse in the direction of the move.
Note that all walls are selected, but the roof moves as well.
3. Changing Structure Ceiling Depth (Bug 1728)
Changing the ceiling depth of the top floor in the structure input dialog after walls have already been created is no longer incrementing the wall heights of existing walls on the top floor by the ceiling depth.
4. Upward Extending of Non-Shear Walls (Bug 1779)
When the Extend Walls button is invoked, non-shear walls on the first level are no longer copied as shear walls on the top level.
1. Meta File and Project File in Separate or Renamed Folders (Bug 1740)
If a CAD metafile is not in the same folder as when it was first imported, the program prompts the user to browse for the location of the CAD metafile to display, but Shearwalls was unable to retrieve and display the file selected by the user. This has been rectified, and you now have the ability to send complete project specifications, including the CAD file, to other WoodWorks users.
2. Log Filename Persistence (Bug
1851)
The filename of the log file was not updated when you changed the project file name. Therefore, when a design was run when the project is still called “Untitled.log” it maintained that name, even after the project file was given a more meaningful name. The log file file name is now updated to correspond to the project file's current filename.
3. Rigid Distribution Information Clearing in Log File (Bug 1852)
- The rigid distribution analysis in the log file is no longer being recorded for each design run of the software, when it should be clearing each time.
- The program no longer repeats the title, date and time for each building level. These are now output only at the start of the analysis.
4. Truncated Elevation View Material Information and Legend (Change 6)
The printed version of the Shearwalls output form was cutting off the legend and wall material information at the length of the wall, even when there was room on the page to print it. This has been corrected.
5. Unreadable Design Results with Combination Printers (Bug 1790)
For certain printers, the design results reports shown both on the screen and as printed were very narrow with a large right margin. All information was unreadable. This occurred primarily with printers that combined print, fax and/or scanning capability. Steps were taken to correct the problem, and these were effective on the one printer model that was tested.
6. OCX Files in Installation (Change 7)
Updated VSPrint and VSPDF OCX files that are included in the installation to implement the enhanced report viewer/print utility with the most recent versions of these files.
7. Immediate Effect of Default Settings (Bug 1693)
In the Default Settings page, the asterisk indicating immediate effect of Roof Slope was truncated, and for Roof Overhang it was missing completely. They have been restored.
Shearwalls 7.0 – December 21,
2007 - Design Office 7
The changes to
Shearwalls for Version 7 listed below take into account the changes in the
National Building Code of Canada (NBCC) for the 2005 Edition vs. NBCC 1995.
These and other changes are also taken from the January 2003 Update and the
January 2005 Supplement to the CSA O86-01 Standard. Further information was
taken from the NBCC Structural Commentaries.
Many other changes,
not related to new design codes, are also listed. The following are highlights
of the changes, with links to the full description below, followed by an index
to the changes, followed by the descriptions of the changes themselves.
Highlights
Design Code
Updates
The program
implements the new procedures for National Building Code of Canada (NBCC) for
the 2005 Edition, replacing those of NBCC 1999, for both wind and seismic load
generation.
Other changes are
taken from the January 2003 Update and the January 2005 Supplement to the CSA
O86-01 Standard, and further information was taken from the NBCC Structural
Commentaries.
Seismic
Irregularities
The program now
analysis the structure for irregularities according to NBCC Table 4.1.8.6 and other
parts of NBCC 4.1.8. It outputs a table of seismic
irregularities, detects the irregularities in the structure, and informs you
when the regularity invalidates design, identifying the precise location of the
irregularity and the reason for design failure.
Undo/Redo Feature
The program now allows the user to revert graphical input operations in
the interactive Plan View and data
input operations in its associated input forms, and to restore the actions that
were undone.
Building Model
Improvements
The program now
allows you to exclude shadowed portions of the roof and walls when generating wind
loads, allows up to six
building levels
, and allows CAD import on each level.
Load and Force Distribution Improvements
The program has
implemented offsets and new
load combinations for
hold-down and compression force calculations, allows you to specify shearwall capacity
for drag strut calculations, and has updated the accidental
eccentricity factors
for rigid distribution.
Improved
Graphics
There are now explanatory legends in Plan view and Elevation view, a view showing all the critical forces in one diagram, depiction of vertical load transfer elements, and improved layout of forces in Elevation
view.
Enhanced Output
Reports
The program has a new output report viewer with formatted, graphical output organised into easy-to read tables. It
also allows such features as navigation tools, zooming, page range printing,
and file output to .pdf or .rtf files.
All tables have been provided with legends explaining the headings, the data, and certain
design assumptions.
Documentation
An up-to-date version
of the On-line CSA-O86-01 design standard in .pdf format has been
provided. The on-line help has been updated to reflect the current program and
converted to Vista-compatible Html help. The current design codes are displayed in the
user interface and design reports.
Bugs
Numerous problems
with program operation have been resolved, in the following areas: wind load generation, seismic load generation, modelling the structure, user
input, load and force distribution
through the structure, shearwall design, graphics, output of
design results, and file operations.
Important: You may need to re-examine past projects in light of these
issues.
Index to Changes
The links below lead to descriptions of
the changes made to WoodWorks Shearwalls for Version 7.0.
1. NBCC
2005 Wind Load Generation
2.
Overlapping Building Elements (Shadowing)
1. NBCC
2005 Wind Load Generation
3.
Seismic Load Generation Bugs
4.
Current Building Model Bugs
E: Load and Force Distribution
1.
Hold-down and Compression Forces
2.
Distribution of Loads to Shearline Forces
4. Load
and Force Distribution Bugs
1.
Shearwall Design Bugs and Minor Improvements
2.
Hold-down forces, anchorages, and compression forces
1. New
Viewer and Report Format
I: Documentation and File Operations
1.
NBCC
2005 Wind Load Generation
a) Importance Categories and Factors
Input of importance
categories in Table 4.1.2.1and calculation of factors in 4.1.6.1 has been
implemented. The importance factor has been added to the equation for wind
pressures in 4.1.7.1.
The Building use input in the Site Dialog has been changed to Importance category, the new categories
have been implemented, and a full description of the categories from table
4.1.2.1 has been added.
Velocity pressure q in 4.1.7.1(4) has changed. It is now
based on a probability of 1-in-50 year return period. It was previously 1-in 10
for CC, 1-in-30 MWFRS, and 1-in-100 for post disaster. These inputs have been
removed from the Site Dialog. Only one input is now in the Site Dialog.
d) Default Reference Wind Velocity
The default reference
wind velocity in the Design Settings can now be set via a dropdown list giving
the design q for dozens of Canadian cities, taken from Appendix C of the
NBCC.
A dropdown list has
been added to the site dialog to allow selection of open or rough terrain.
The factor Ce
has been changed according to from 4.1.7.1(5) has been implemented:
-
(h/10)0.2
but not less than 0.9 for open terrain (essentially the same as in NBCC 1995
and Sizer 2002a
-
0.7(h/12)0.3
but not less than 0.7 for rough terrain.
The gust factor Cg
from 4.1.7.1(6) has been implemented:
-
Cg = 2.0 for main structural members (6a),
-
Cg = 2.5 for C&C loads (6b)
An input field has
been added to allow user input of the internal gust factor Cgi to
allow for detailed calculations allowed for in 4.1.7.1(6) (c)
h) Internal Pressure Co-efficient Cpi
New internal pressure
co-efficients Cpi have been implemented according to NBCC structural
Commentary I-31.
-
For
Category 1, the lower range has been changed from -0.30 to -0.15
-
For
Category 2, the range has changed from -0.7 to 0.7 to -0.45 to 0.3
-
Category 3
is the same
i) Low-rise Note 8 – Low-slope Windward Loads
In in the design
results, log file, and load list in load input view, references to Note 9
regarding the splitting of windward loads on, low-sloped roofs has been changed
to Note 8.
j) Low rise Note 5 Roof Slope Angle
Note 5 to Figure I-7
allows eave height as reference height for angles less than 7 degrees now,
instead of 10.
k) Component and Cladding Reference Height
Note 5 regarding
reference height based on roof angle has been removed for component and
cladding wall design. The reference height shown in the diagram is always mean
roof height.
We removed reference
to “Medium-rise” and “All heights” when referring to this figure, and instead
refer to it as the Fig. I7 procedure. The design code refers to it as a
procedure for flat-roofed structures, but Shearwalls uses it for all roof
types, as an alternative to the low-rise method for those structures that do
not conform to the low-rise limitations.
2.
Overlapping
Building Elements (Shadowing)
Add setting in Load
Generation options for "Exclude roof portion covered by other roof. It is
checked by default.
If checked, the
program discounts the redundant loads that are created when one building roof
surface is in front of another. In doing so, it divides the roof panels into
triangular and trapezoidal segments, increasing the number of wind loads on the
structure. It takes into account end zones and NBCC I-7 Note 8 loads when
splitting up roof.
If a roof frames into
a wall on the same storey of a taller block, then the covered portion of the
wall is excluded. In some cases the portion of a roof covered by a wall is
excluded.
a) Wind Load Generation On Vertically
Discontinuous Walls (Bug 1797)
The wind loads
generated on an upper-level wall that is not the same extent as the lower wall,
use the extent of the lower wall for the loads on the bottom half of the upper-level
wall. Therefore, many configurations received more or less loading than they
should, for example:
-
A wall that is common to two blocks in plan,
but exists on an upper level on only one of the blocks.
-
Overhangs
or cantilevers
b) Load Generation after Block Size Change (Bug
1768)
The ridge elevation
was not being properly updated upon change in block size, resulting in
inaccuracies in many aspects of load generation in this case, including:
-
the
tributary width of wind loads
-
calculations
using mean roof height or ridge height
This problem would be
corrected if you modified the roof via the roof input dialog after changing
block size. As most users modify the blocks, then proceed to define the roof,
it rarely occurs in normal practice.
c) Exposure Factor for Imperial Units (Bug 1670)
When imperial units
were selected, the exposure Factor Ce reported in the Design Results and used for wind load
generation was always 1.72, but it should be related to building height by NBCC
1995 Table 4.1.8.1. As a consequence, wind loads are increased by between 40%
and 90%. When metric units were selected,
the exposure factor was correct.
d) Zero-overhang roof wind loads (Bug 1697)
When generating loads
on the side panels of gable end roofs with no overhang, extra tiny loads were
sometimes showing up at the edges of the roof in Plan View. They no
longer appear.
e) Low-rise Note 8 Loads on Hip Ends (Bug 1623)
For hip roofs, the
loads on the upper portion of the hip ends generated according to the Low-rise
Method in NBCC Commentary B7 Note 9 (now I7 Note 8) led to positive wind loads
despite the fact that they have negative coefficients. This has been corrected.
Problems with
definition of end zone on convoluted structures were fixed in Version 2002a.
g) Wind loads on trapezoidal roof panels (Version
2002a)
Problems that
occasionally occurred with wind loads on trapezoidal roof panels were fixed in
Version 2002a.
h) Flat Roof Load Generation (Bug CSW7-12)
The program was
creating both Case A and Case B loads for only one direction on the structure
in the case of a flat roof, leading to unequal loading for square structures.
The program now considers only the loads in the direction of the force for flat
roofs, which have the same coefficients for Case A and Case B.
i) Generation after Wall Move via Keyboard Input
(Bug CSW7-13)
When loads are
generated after walls are moved by changing their co-ordinates in the wall
input form, wind loads were not generated on some of the moved portions of the
walls. This affected structures such as L-shaped, U-shaped, and those with
vertical irregularities and has been corrected.
1.
NBCC
2005 Wind Load Generation
a) Seismic Design Not Required
A design note
indicates seismic design not required if f S(0.2) as defined in sentence
4.1.8.4(6) less than or equal to 0.12
Seismic design is not
allowed for buildings over a maximum mean roof height hn of 20
metres or 60 feet, in order that the design provisions that apply for Ta
<= 0.5 are used. This height also roughly corresponds to the maximum number
of stories allowed for wood-frame construction. A warning message appears when
seismic design is attempted for taller buildings.
The Soil Category
input has been changed to Site Class, with the classes and abbreviated
descriptions from Table 4.1.8.4A.
d) Spectral Response Acceleration Input
Damped spectral
response accelerations: Sa(0.2), Sa(0.5), Sa(1.0),
Sa(2.0) edit boxes have been added to the Site Information input form.
e) Default Spectral Response Acceleration
The default values of
the spectral response accelerations that appear for new files, and are
specified in the Design Settings via a dropdown list giving these values for
dozens of Canadian cities, taken from Appendix C of the NBCC and Table J-2 of
the structural commentaries.
Values of
acceleration- and velocity-based site co-efficients Fa and Fv
have been implemented in accordance with Tables 4.1.8.4B and 4.1.8.4C. Linear
interpolation for is used for intermediate values of Sa(0.2) and Sa(1.0)
Acceleration- and
velocity-based site co-efficients, Fa and
Fv edit boxes have been added to the Building Site dialog for user input.
These are activated for site class F to allow for user determination of these
values according to 4.1.8.4 (5), which calls for site-specific geotechnical
investigations.
h) Spectral Acceleration Values S(T)
-
FaSa(0.2) for T<=0.2s
-
FvSa(0.5); FaSa(0.2) whichever is
smaller for T=0.5s
-
FvSa(1.0) for T<=1.0s
FvSa(2.0) for T=2.0s
To comply with 4.1.8.9,
the existing input for R has been changed to input two factors for each
direction: ductility- related force modification Factor Rd, and overstrength-related force modification factor Ro.
j) Additional
System Restrictions
To comply with
4.1.8.10, Additional System Restrictions,
the program does not allow seismic design for Post disaster building shall have an SFRS with
Rd or 2.0 or less. The user is notified in this case.
The fundamental
period T is now calculated according to 4.1.8.11 3 c), T = 0.05 (hn)3/4,where
hn is the mean roof height of the structure.
The earthquake force
V is calculated according to 4.1.8.11:
-
V = S(Ta) MvIEW / (RdRo)
-
Vmin
= S(2.0) MvIEW/(RdRo)
-
Vmax(Rd >= 1.5) = 2/3 S(0.2) IEW/(RdRo)
A higher mode factor
of Mv of 1.0 is used, corresponding to Ta < 1.0 from
Table 4.1.8.11, which in turn corresponds to all buildings less than the
maximum height restriction given above..
The categories for
importance factor have changed, but the seismic co-efficients for the
corresponding factors (4.1.8.5) are the same as in NBCC 1995. Refer to the
section on Wind Load Generation for changes to Importance Categories and input
of these categories.
The program now
analysis the structure for irregularities according to NBCC Table 4.1.8.6 and
the references to these irregularities throughout the NBCC 4.1.8. For each irregularity, the table contains
-
Irregularity
Number
-
Type of
Irregularity from 4.1.8.6
-
References
-
Whether
the irregularity is detected by the program or must be checked manually by the
user of the program
-
The level,
shearline, and force direction for which the program is irregular. The words
“Must check” are placed in this column if other parameters are such that you
must check for the existence of the irregularity.
-
The level,
shearline, and direction for which the program fails design due to the
existence of the irregularity and other parameters making design illegal.
-
The
numbers of the notes below the table that apply to the irregularity.
The program issues
bold warnings in advance of the table of two circumstances:
-
If design
fails because the program detects and irregularity and illegal seismic design
parameters for that irregularity
-
If the
program detects design parameters such that the user must check for an
irregularity that the program cannot detect.
-
Warnings
In advance of the
table, the program outputs
-
the value
of IEFaSa(0.2), upon which many of the rules
for irregularities are based
-
a note
saying that only the provisions based on Ta less than 0.5s and height less than
20 m are considered, as the program restricts seismic design to heights less
than that
Notes are output below
the table giving
-
reasons
for failure or that seismic design is not permitted
-
reasons
that the user must check for an irregularity or other parameters
-
reasons
that a check is not required or that an irregularity does not apply
-
other
explanatory information
There are a total of
21 possible notes. The notes are presented as a, b, c, d, … to avoid confusion
with the irregularity numbers. The letter(s) for the note(s) applicable to the
irregularity are given in the table for that irregularity.
After the table and
notes, the program lists the irregularities, giving a description of the
irregularity and an explanation of how Shearwalls treats the irregularity. .
When a discontinuity
is found that causes design to fail, or the program detects when the user must
check for a discontinuity, following shearwall design a total of 7 possible
explanatory warning messages are sent to the screen. These messages are for
-
Post-Disaster
and Types 1 or 7
-
Post
disaster and Type 3, 4, or 5
-
Type 3, 4,
5 and there is a weak storey, so no design.
-
Type 3, 4,
5 and no weak storey, but program uses
shear wall capacity in place of design shear for hold-down calculations
-
Type 6,
and seismic design not permitted unless design forces factored by RoRd
-
Type 6,
Seismic design not permitted
-
User must
check for Type 7.
g) Type 1 - Vertical stiffness
Design code
references: NBCC 4.1.8.7-1c, 4.1.8.10-2a, NBCC Commentaries J-126.
If applicable, must
be checked by user, who can use relative rigidities of shearlines in Shearwalls
Design code references: NBCC 4.1.8.7-1c.
No effect for
buildings less than 20 m height and Ta < 0.5, or all buildings in
Shearwalls.
Design code
references: NBCC 4.1.8.7-1c, 4.1.8.10-2a, 4.1.8.15-2, Commentaries J-126,156.
Shearwalls checks
using the nearest and farthest points from all walls in a storey for each
direction. It shows the storey with a long SRFS in the table, and the affected
direction(s)
Design code
references: NBCC 4.1. 8.7-1c,
4.1.8.10-2a, 4.1.8.15-2, Commentaries J-126,156, 207.
Shearwalls detects
whenever the ends wall segments on adjacent storeys do not line up to within
3”. It shows both upper and lower storey in table, e.g. 4,3, and shearlines
affected.
k) Type 4 - In-plane stiffness
Design code
references: NBCC 4.1.8.7-1c,10-2a,
4.1.8.15-2, Commentaries J-126,156, 207.
Design code
references: NBCC 4.1.8.7-1c, 4.1.10-2a, 4.18.15-2, Commentaries J-126,156.
Shearwalls detects
wherever shearwalls do not exist on a shearline for particular level, and the
program has transferred the force from the shearline on the floor above
directly into the diaphragm. It shows the storey without shear-resisting
elements in the table, and the directions(s) affected.
Design code
references: NBCC 4.1.8.7-1c, 4.1.8.10-1,2b, Commentaries J-126, 156.
Shearwalls determines
the total capacity of all shearwalls for each direction on each level, and
reports weaker lower levels in the table.
n) Type 7 - Torsional Sensitivity
Design code
references: NBCC 4.1.10-2a,
4.1.8.11-9,10, Commentaries J-127, J177-9.
Ratio B of maximum to
average storey displacements is greater than 1.7. Shearwalls does not at this
time perform deflection analysis, so this must be calculated by the user.
Design code
references: NBCC 4.1.8.7-1c,
Commentaries J-127.
Shearwalls does not
currently allow input of skewed shearwalls, so this irregularity does not
apply.
3.
Seismic
Load Generation Bugs
a) Roof Height for Vertical Force Distribution
(Bug CSW7-7)
The height hn for
the highest floor used for vertical force distribution as per NBCC 1995 4.1.9.1
(13) (now NBCC 2005 4.1.8.11 (6) ) was using the eave height of the roof,
rather than the mean roof height. It now uses the mean roof height.
b)
Snow Mass on Flat
Roofs (Bug 1645)*
Snow mass was not
accounted for when building mass was generated on a structure in which all roof
blocks are set as a flat roof.
The program now allows the user to revert graphical input operations in
the interactive Plan View and data input operations in its associated input
forms, and to restore the actions that were undone.
An Undo and a Redo button are added to the control bar
above the Plan View window. These items are also placed in the Edit menu.
In addition, the keystrokes Ctrl-Z and Ctrl-Y activate the undo
and redo commands, respectively.
This feature is active in the Structure, Walls,
Openings, and Roofs actions, in both Plan View and its
associated data input forms. It is not active in the CAD Import, Site
Dialog, Load Generation Loads and Forces
Operations that create a change to the physical structure of the
building are affected, such as moving or resizing blocks, walls, openings and
roof panels, or changing the material composition of walls.
Merely moving the mouse, selecting a new object, or navigating amongst
input controls, and changing building levels or views, are not included.
Changing certain input controls that have no immediate effect on the building,
like Roof slope - Opposites the same are also not included.
As many as five consecutive operations can be undone, and redone again.
e) Interaction with File Save Command
The undo sequence is preserved through File Save commands, so
that the user can undo and redo after saving. A document that has an operation
undone then redone is still considered a changed document by Windows.
This version extends
the ability to import a Windows metafile exported from CAD software to the
upper levels of the structure. Previously only the first level footprint could
be imported.
The Wizard has been
expanded to be a CAD Import Input View, similar to the other input views, that
controls the file input for each level. It also continues operate as a wizard
that guides you through the positioning and scaling process.
If you choose not to
import a metafile for a particular level, the metafile for the floor below will
be shown. The first level file is required.
You can choose to
bypass the scaling operation for any level but the ground level by specifying
that any upper floor metafile has the same scaling factor as the level below.
Once the input,
positioning, and scaling process is complete, the metafiles for a particular
floor will be visible in any other action of Plan View, when you press
the CAD Import button.
Shearwalls now allows
input of buildings to a maximum of six levels, as opposed to the four levels
previously allowed. This allows for the maximum of 5 levels allowed for certain
structures in IBC (Table 503), plus one below-grade level.
The spin control
which is used to create the number of levels on each block now has an upper
limit of 6 rather than 4. The Structure input dialog has two additional
levels for which wall height and floor/ceiling depth can be entered.
The Levels controls
in Plan View and Elevation View now have an upper limit of six levels rather
than four. Elevation view can now display all six levels at once.
The Generate Loads View, Load
Input View, and Add load dialog filters for
input and viewing loads now extend to 6 levels.
All Design results
tables have been expanded to show more sections of data corresponding to
building levels, and/or show levels up to 6 rather than 4 in the Level
column:
e) Analysis and Design
All
load generation, vertical and horizontal load distribution, and shearwall
design begin the design cycle on up to the 6th level rather than the 4th,
including two more iterations corresponding to the extra levels. Note that this
can result in significantly heavier loading than for four stories, and a
corresponding increase in processing delay.
4.
Current
Building Model Bugs
a) Three Block Roof Joining (Bug 1777)
The roof on the
middle block in a 3-block configuration, when all three blocks have the same
width, was not joining with the other two blocks.
b) Monoslope Roof Creation (Bugs 1599 and 1600)
It was not possible
to change the roof angle in roof input view in order to create a 90-degree
panel for a monoslope roof situation.
The program behaviour
when attempting to create a monoslope roof via a movement of the ridge location
was erratic and unpredictable. It was only possible for some building
configurations.
Monoslope roofs were
thus difficult to achieve.
c) Monoslope Roof Ridge Direction (Bug 1667)
After changing the
ridge direction for monoslope roofs, the program would revert to the original
ridge direction on the next user input action.
d) Zero Wall Height for Uneven Blocks (Bug 1569)
If the ceiling joist
depth is changed while entering the data in the Structure Input form for
a block with fewer stories than other blocks, the wall height on the storey
above the lower block's ceiling depth, on the taller block, was being set to
zero. This has been corrected.
e) Extend Walls Crash (Bugs 1440 and 1783)
The Extend Walls feature was causing
Shearwalls to crash, for complex multi-block structures where adjoining blocks
differ in levels by 2 or more, particularly when the blocks are arranged in an
L- or U- shape.
Occasionally the
program would crash upon pressing Extend
Walls for any type of structure. due to random numerical precision issues.
f) Changing Storey Height after Extend Walls (Bug
CSW7-35)
If the storey height
is changed in Structure input after Extend Walls is invoked and when
imperial units are employed, the walls would sometimes not be moved to the
height of the storey that was raised, causing a gap between the wall and the
diaphragm above.
-
When
certain configurations of three or more blocks were created such that they were
diagonally abutting and Roof action selected Shearwalls would freeze.
-
When three
blocks, with identical Y coordinates, were created, with the center block
containing more levels than the outside blocks, the roof on the centre block
was corrupted.
-
When
multiple blocks were created, and a wall from a block, which had blocks on
either side, was first segmented and the new wall segment was moved, the blocks
became disjoint and a gap appeared.
-
When two
blocks with different levels were created, and their bordering walls were
manipulated such that the higher block had a smaller footprint at the
interface, upon extending the walls to upper levels, walls were created that
were longer than they should have been.
-
When three
blocks were defined sequentially, with the outer blocks set to have 2 levels
and the middle block set to have one level, upon extending the walls to upper
levels upper level walls were generated for the middle block.
-
The slope
of certain roof panels which joined other panels slopes were being set
incorrectly causing erroneous looking roof diagrams and affected wind load
calculations involving roof slopes.
-
When two
adjacent blocks were positioned such that they both had an outside wall at the
same X or Y coordinate the roofs did not join, and it was impossible to make
them joins
-
When the
roof configuration such as roof type, slope, location and/or elevation was
modified the change was not reflected in adjacent block's roofs which were
joined before the change.
-
When three
or more adjacent blocks were defined such that the middle block had fewer
levels than the outside blocks, the extension of walls to upper floors caused
the program to hang.
-
When
exterior walls connected to interior walls were moved, the program could shut
down when walls were extended upwards.
-
Under certain circumstances the automatic
deletion of walls, resulting from the movement of wall segments, would cause
the application to crash.
The program now
requires entry into Loads and Forces view before proceeding to the Design
command, and upon first entering the Loads and Forces view provides the
user with advice as to which types of manually entered loads might be required.
The Design button
and menu item will remain disabled until you first enter the Loads and
Forces view. The message given below will appear when you first enter Loads
and Forces.
If loads have not
been generated in the Load Generation action, the message reminds you to
generate loads, and then advises about
-
dead and
uplift loads for hold-down calculations
-
using
direct shearline forces to model buildings adjoining other structures
If loads have already
been generated, the program provides the same advice about dead, uplift loads
and direct shearline forces, and also about the following loads that cannot be
generated:
-
from large
installations, parapets, etc
-
from
complicated roofs
c) Direct Shearline Forces Label
The label in the
group box in the Add Loads dialog
that currently says Implement as a factored force applied directly has been
changed to Add as a factored force
directly (parallel) to the shearline.
The buttons
called
Generate and
add to Loads,
Regenerate Loads
have been renamed to make their functionality
more clear, they are now
Generate loads
on selected levels,
Delete all and
regenerate
The button named Delete all generated loads remains the same.
An input has been
added to allow the user to choose whether drag struts are based on shearwall
capacity or applied load, similar to hold-down forces.
b) Drag strut and Hold-down Force note
A note has been added
to indicate that the user choice of “Applied loads” for hold-down and drag
strut forces will be over-ridden by “Shearwall capacity” for seismic
discontinuities, due to NBCC 4.1.8.15 (2).
a) User-applied Wind Shearline Forces (Bug 1593)
When entering wind
loads on a building face, the default extent of the load was furthest extent of
shear resisting elements in the orthogonal direction to the wind loads, and not
the length of the building face bearing those loads, when there were non-shearwalls
at the ends.
b) Distribution Method for User-applied Shearline
Forces (Bug 1596)
The Distribution
method of user-applied shearline forces was not saved with the project
file, so the Distribution method for such a force was being reset
to All Distribution Methods when reopening the project file. This has
been corrected.
c) Default Wind Load Extent (Bug 1778)
When checking the
"Implement as a factored force applied directly", the wind direction
changes to "East to West” from "Both directions", so that often
loads were inadvertently entered only in one direction.
d) East-west Shearline Forces in Load Input List
(Bug 1590)
For East->west
or West->east wind shearline forces input directly, the load direction
displayed in the load list of load input view was the opposite of the input
force. This did not occur for north-south forces, and had no effect on load
analysis or design.
e) Levels in Load Input (Bug CSW7-10)
The range of levels
in the Add a New Load input form is
now synchronized with the range of levels in the Load Input form. Previously it was resetting to 1 to the maximum
number of levels in the structure. The
default should be the same as the “Levels” in the “Load Input” dialogue box.
f) Wall Type Update on Change of Standard Wall
(Bug 1730)
The wall type shading
in the Plan View drawing did not
update immediately upon selection of a new standard wall.
g) Rigid Diaphragm Loads and Forces Settings (Bug
1769)
h) Point Load on Opening End (Bug 1464)
When a point load was
added to a wall directly over the start or end of an opening, the program was
crashing.
i) Deleting User-applied Forces
The program would
crash any time a user-applied shearline force was deleted. This has been
corrected.
j) Status Bar Messages (Bug 1617)
The status bar was
not displaying any message for the Site Dialog or any of its controls, while
for the Wall Input, Roof Input, Generate Loads and Load Input views the
messages were displayed only for some of the input controls and were truncated
in a few instances. New status bar messages have been made for all controls in
these views, and truncated status bar messages have been abbreviated.
k) Inconsistent Capitalisation (Bug 1453)
Input fields
throughout the program composed of two or more words were inconsistently
capitalised. The style is now sentence case unless it is a title to a window
E: Load and Force Distribution
1. Hold-down and Compression Forces
A setting has been
added to the Default Settings page allowing input of the distance from the end
of a wall or opening that a hold-down can be located. It can be saved for a
particular project, and as a default value to be used for new files. A value of
zero cannot be entered, so there must be some hold-down offset. The
"original default setting that comes with the program is setting is
3"
b) Hold-downs at Contiguous Walls
The hold-down offset
means that compression forces at the end of one wall are not at precisely the
same location as tension forces at the end of the other. In Sizer 2004b, these
forces were cancelling.
The moment arm used
for hold-down force calculations is
-
For
anchorages, the segment length minus the largest of 300mm and twice the
hold-down offset,
-
For
hold-downs, twice the hold-down offset.
d) Vertical Force Accumulation
Where a compressive
force lines up with a tension force on the floor below, such as for offset
openings, the program now correctly uses the difference between these forces as
the resulting force. Previously it was adding the magnitude of the tension force
in one direction to the tension force in the opposite force direction.
e) Wind
and Dead Load Combinations
The new load
combination for combining wind and dead loads at hold-down locations from NBCC
4.1.3.2 is used – 0.95D + 1.4W. The wind factor has changed from 1.5 and the
dead factor from 0.85.
The dead load factor
for dead loads combined with wind loads used for compression forces combined is
1.25, as it is not counteracting uplift.
f) Compression Force Load Combination (Bug
CSW7-19)
The load combination
1.25D + 1.4W has been implemented for downward compression forces. Previously,
the program was erroneously using the 0.9D combination.
If the program
detects In-plane or Out-of-plane irregularities 3, 4, or 5 from Table 4.1.8.6.
If there is a weak storey below, design is not allowed, if there is, all
hold-down and drag strut forces use the shearwall strength rather than the
applied force, according to 4.1.8.15 (2).
An anchorage can now
be placed only where there is a tension end of a shearwall on the floor below,
so that the force is distributed directly to the wall chord and the hold-down
or anchorage below. Previously the anchorage force could be distributed through
the shearwall from mid-segment to the shearwall ends.
A note was added to
the hold-down table when hold-downs rather than anchorages were created for
that purpose.
Vertical
Elements for Hold-downs
Where previously an
anchorage force would meet a shearwall on the floor below at mid-segment, the
program creates a vertical element and a hold-down force, and transfers the
force through that element further down through the structure.
i) Design Setting for Force Calculation
A new Design Setting allows you to choose
whether to use the applied shear
load or the tabulated shear strength in calculating hold-down forces. The default
value is applied shear, you should change this when designing connections if
the design code specifies tabulated shear.
When shear capacity
is required due to seismic irregularities, then this takes precedence due to
2.
Distribution
of Loads to Shearline Forces
a) Rigid Seismic Load Distribution
A accidental
eccentricity of 10 percent of the building width at each level has been added
to the torsional moments for rigid diaphragm load distribution for seismic
loads, to comply with 4.1.8.11 10 (a).
b) Rigid Wind Load Distribution
In the absence of any
provisions to add wind load eccentricity, the torsional moments for wind load
distribution now consider only the moments due to asymmetric loading, and no
accidental eccentricity.
a) Design
Setting for Force Calculation
A new Design Setting allows you to choose
whether to use the applied shear
load or the tabulated shear strength in calculating drag strut forces. The default
value is applied shear, you should change this when designing connections if
the design code specifies tabulated shear.
b) Calculations Seismic Irregularity
Furthermore, the
program automatically changes the calculation to shear strength in the presence
of a seismic irregularity when such an irregularity calls for it. Refer to the
section on seismic irregularity analysis.
4.
Load
and Force Distribution Bugs
a) Drag Strut Forces for Wind and Seismic (Bug
CSW7-40c)
Sine version 2002 was
released, when wind and seismic forces were both present on a shearline, the
drag strut force calculations were incorporating both wind and seismic shear
forces, rather than each separately, resulting in a much too heavy drag strut design
force.
b) Hold-down Force Distribution into Interior of
Wall Segment (Bug 1795)
The calculations for
Hold-down force distribution from an upper wall to the interior of a wall
segment below were using the shearline ends rather than the wall ends,
resulting in miscalculation of the force magnitude and misappropriation of
these forces to the line end rather than wall end. Affected only shearlines
with multiple walls.
The program now
transfers these forces directly downwards via a vertical element.
c) Compression Hold-down Force Accumulation (Bug
1796)
Compression hold-down
forces shown in elevation view were showing the forces from that level only,
without including the accumulated force from the levels above.
d) Rigid distribution of negative direct loads
(Version 2002b)
Before version 2002b,
the calculation for torsional shear force for the rigid distribution method,
was omitting the negative direct loads
e) Critical Negative Wind Loads (Version 2002b)
Before version 2002b,
in the unlikely circumstance that negative wind loads are critical, the program
was creating hold-down forces in wrong direction and not designing walls
correctly
f) Distribution of Wind Uplift Loads to Openings.
(Version 2002b)
Before version
2002b,The partitioning of line loads over openings and non-FHS segments were
incorrect when wind uplift loads were present and seismic building masses were
also present.
1.
Shearwall
Design Bugs and Minor Improvements
a) Design Search Failure for Openings at End of
Line (Bug CSW7-17)
The design search
would fail to find passing shearwalls when an opening existed exactly at the
beginning or end of a shearline.
b) Wall Groups Designed for Opposing Directions
(Bug CSW7-41)
The program was not
always ensuring that the wall materials designed for opposing force directions
were the ones needed for the strongest of the two cases, instead it could
design separate materials for opposing directions. It now reports just one
material wall group for the wind case, and one for the seismic case.
c) Similar Materials on Shearline (Bug CSW7-42)
d) Blocked Gypsum Sheathing Capacity (Bug 1589)
Shear capacity of
blocked gypsum incorrectly follows the rules for unblocked gypsum (CSA 086-01,
Table 9.5.1B, Note 1) in that it is being reduced when frame stud spacing is
greater than 400mm. This results in a conservative shear capacity.
e) Non-shearwalls Contribute to Shearline Capacity
(Bug 1587 )
In the Shear Results table of the Design Results, the total shear capacity
of the shear line and the design ratio were including the capacities of wall
segments that exceed FHS aspect ratio check in the total shear capacity of the
shear line. However, the program was not using these incorrect values for
shearwall design, instead using the correct individual segment values.
f) C&C Loads for Sheathing Design (Bug
CSW7-43)
The C&C loads
used for sheathing design were the lower interior zone loads rather than the
higher end zone loads. This resulted in non-conservative design, and has been
corrected.
g) Nail Withdrawal Failure for Non-loaded Surfaces
(Bug 1586)
As a result of bug
1587, above, for known sheathing capacity and no C&C loading, Shearwalls
sometimes report failure in Elevation
View because of zero nail withdrawal capacity.
h) Nail Withdrawal Capacity (Bug CSW7-44)
The nail withdrawal
capacity was not incorporating the 0.6 safety factor ρ according to 10.9.5.2 of CSA O86. This
resulted in non-conservative design, and has been corrected.
i) Nail Sizes Greater than 3” (Bug CSW7-48)
Due to instabilities
created by the application of 9.4.5.5a),
the restriction in nail size to less than 3.25” for Jhd < 1, nail
sizes greater than 3” have been removed. Nail sizes that large tend to split
plywood anyway.
As a result, some
designs that required nail sizes larger than 3” to pass the nail withdrawal
check in areas of high C&C wind loading will now fail. If this happens, an
increase in interior spacing is needed.
j) Jhd Factor for Non-aligned Shearwall
Segments (Capacity (Bug CSW7-45)
When the end of a
shearwall segment with hold-downs occurs where there is no segment end on the
floor above, the program was applying CSA O86 9.4.5.3 for a Jhd
factor < 1, which is the literal interpretation of that clause.
However, we believe
that the intent of the clause is to apply this clause when an anchorage exists
above a hold-down to account for the fact that the upper storey anchorage force
will be transferred through the lower storey sheathing, reducing the shear capacity
of the lower storey. Therefore, CSA O86 9.4.5.3 is no longer applied when there
is no anchorage above the hold-down location.
k) Jhd Factor Warning for One-storey
Structures (Bug 1635)
For a single-storey
building, in the Results View, under "SEISMIC DESIGN" for both
Flexible and Rigid Diaphragm, the following message would appear:
** Warning - design
capacity is exceeded because Vrs is zero due to negative Jhd factor
even though, for a single-storey building, Jhd
should never be less than 1
l)
Seismic
Compression Force Location (Offset)*
For seismic design,
the location of compression hold down is offset from end of wall by twice the
user input hold-down offset rather than just that offset. As a consequence, the
compression and tension hold-downs at an opening end are offset from each other,
and the program assigned some of the dead load to one of the hold-downs and
some to the other, rather than the full dead load to both.
Explanatory legends
explaining the meaning of the symbols used for loads and forces in Elevation
View and in Plan View have been added. Separate legends appear for wind and
seismic design, and for Loads and Forces action versus Generate Loads
action
a) Plan View, Loads and Forces Legend
A legend is added to
the bottom left corner of the view. It shows the symbols for shearline forces,
hold-down forces, compression forces, vertical elements, applied shear loads,
dead loads, uplift loads, and discontinuous shearline forces applied as loads.
b) Plan View, Generate Loads Legend
A legend is added to
the bottom left corner of the view. It shows the symbols for generated shear
point loads and line loads, generated building masses, and floor areas for mass
generation. Forces or user-applied loads are not shown in this action.
c) Load Factors and Combinations
When the legends
indicate that loads and forces are factored or unfactored, it means that they
are or are not multiplied by the load combination factor.
There is a line at
the bottom of the plan view screen indicating load combination being used for
hold-down and compression force calculations.
A legend is added to
the bottom right corner of the view. It shows the symbols for tension hold-down
and anchorage, and compression, forces for shear overturning, dead, uplift and
combined, hold-down magnitudes; load combination factors; shearline forces; the
meaning of the various shear force arrows, and the symbol for drag strut
forces. Slightly different legends appear for seismic and wind output.
The large amount of
empty space above the title bar in Elevation View has been reduced to the size
of a reasonable margin.
The title block has
been reconfigured differently for printing and for screen display. It now
shows,
On the first line in
print mode,
"Elevation
View"
On the second line in
print mode, first line in screen mode
shearline name
shearline
location
building levels
shown
On the third line, in
print mode, still on the first line on screen
rigid or
flexible design case
wind or seismic
design
2. Hold-down forces, anchorages, and compression forces
The Critical
Forces choice under Load Direction in Plan View, shows
the critical tension hold-down force at each vertical force collector location.
For low-rise wind loads, it shows the critical force for all reference corners.
This item should be
selected if you want a drawing showing all of your hold-down forces in Plan
View.
Note that the Holddowns and Drag Struts table in the
Results output also shows the critical vertical forces at each hold-down
location. .
Hold-downs are now
moved inside the wall by the hold-down offset distance, and compression hold-downs can no longer coincide with tension
hold-downs.
Hold-downs from the
floor above now appear on the level when there are no walls on that level,
carried through by a vertical element, which is shown as doubled wall stud in
elevation view. .
-
Compression
forces are now drawn whenever the net force is directed downwards, even in the
case that downward dead load dominates upward overturning force.
-
In
Elevation View, A vertical arrow symbol is used to distinguish compressive
forces from hold-downs, and has been extended downwards through the joist area.
The negative sign is no longer shown for these forces. The hold-down magnitude
text is now positioned such that the adjacent compression and tension forces do
not overlap.
-
In Plan
view, compression forces are shown by a circle and the letter C. No
magnitude is shown, as the force does not include other gravity load
combinations and is thus not of sufficient interest to merit the clutter on the
screen
Vertical elements are
created wherever a hold-down or compressive force is created, and it does not
coincide with a wall or opening end (plus or minus hold-down offset) on the
level below. They correspond to either columns or strengthened wall studs.
b) Depiction in Elevation View
This is depicted as
of two light solid lines spaced 3" apart, and a dotted line in the middle
of them, representing a built-up double wall stud. The element centred on the
hold-down of compression force, except where walls meet as described below.
The element extends
from the bottom of the upper floor joist to the top of the lower joists, except
over openings, where the element extends down to the opening top.
In Plan View they
appear as small squares, the same width as a wall, with a dark blue colour
(dark red when a wall is selected). They replace the hold-down or compression
force symbol where they exist.
When two forces exist
where segmented walls meet, usually tension and hold-down forces separated by
twice the hold-down offset, the program depicts only one vertical element,
centred between the forces.
You are able to turn
on and off the display of vertical elements via Settings... Display,
separately for Elevation View. This display setting is also implemented
in the Show menu.
The Critical
Forces choice under Load Direction in Plan View, shows
shearline forces in both directions, and the critical tension hold-down force
at each vertical force collector location. For low-rise wind loads, it shows
the critical force for all reference corners.
For wind design,
applied loads are not shown as their direction would conflict with the forces
reported. For seismic design, the loads are shown.
The diaphragm shear
flow at the top of the diagram now extends the entire width of the shearline,
from the extreme exterior wall at one end to the extreme exterior wall on the
other, through all gaps in the shearline, and over openings and non-shearwalls.
Previously it was incorrectly shown over walls only.
When there is a gap
in the shearline that is actually external to the building, due to a structure
that is U-shaped in plan or in elevation, the program continues to show the
diaphragm shear flow across the gap that is absent a diaphragm and also drag
strut forces leading into the gap.
This indicates more
clearly to the user that the program does not yet deal correctly with this
situation from a load analysis standpoint. The WoodWorks development team is
working on a solution to this problem, and suggestions from users on how to
distribute loads in such structures are welcome.
In Plan View,
now only two of the four selections of the Load Direction choices
currently available for wind are available for seismic, rather than four. The
loads and shearline forces are still shown as bi-directional arrows
e) Negative shearline forces (Version 2002b)
For version 2002b and
7, for forces from negative loading, the program reverts the direction of the
arrows and displays the magnitude as positive.
The drag strut forces
that occur at wall ends have been moved up closer to the top of the wall. All
the forces have been provided with a circle at one end to distinguish them from
shearline forces and to emphasize that, like tension hold-downs, a mechanical
connection is required.
In Elevation View,
shearline force arrow has been reduced in size, includes the entire tail,
and no longer goes missing when there is a gap in the walls at the end of a
shearline.
a) Opening Colour due to Gray Block Outline (Bug
1694)
The gray outline of
blocks and roofs is no longer being drawn over walls, and openings. It was
discolouring walls and obscuring openings
b) Force Symbols on Non-Shearwalls in Elevation
View
The design shear was
displayed at the base of non-shearwalls in the elevation view if the non-shearwall
was once a shearall, and persisted after another design was run.
After changing the
wall type in an entire shearline from shearwalls to non-shearwalls, the
shearline forces were still being displayed in elevation view after the next
design
c) Failed Walls in Elevation View (Bug CSW7-16)
When either an
opening or a segment too narrow for design existed at the end of a shearline,
that line would not display the word FAILED over the elevation view drawing
when the shearall design failed for that wall.
1.
New
Viewer and Report Format
-
Full page,
page width or zoom
-
Navigation
between pages with control at top of view
-
Navigation
directly to table with menu in toolbar
-
Keyboard
and mouse navigation
-
The output
is now reorganized into four major sections: Project Information, Structural
Data, Loads, and Design Results
-
Show
button menu reorganized and table menu organized to reflect organization of the
results tables
-
The
display of all loads tables can be toggled on or off with single menu
selection
-
Pagination,
page breaks after tables, table title and continued on each page
-
Automatically
switches between landscape and portrait to fit tables option
-
No longer
shows titles if tables or sections are not shown.
-
Bold,
Arial font headings and titles, fixed pitch table data, notes in italics
-
Tables
have distinct headings and columns
-
Borders
around tables
-
Blank
lines inserted in tables with subtitle to delineate shearline or level
The Materials, Dimensions, Loads, and
all Design Results tables now have a
legend below the table which
-
gives the
meaning of all the columns in the table
-
defines
any abbreviations used
-
provides
additional design notes as needed.
User can choose to
save output in
-
Rich text
file (.rtf) format or
-
portable
document format (.pdf).
-
Able to
print individual pages or page ranges.
-
New
setting in Format page allows you to activate automatic switching to landscape
mode for font sizes greater than 10 in results view
a) Remove Shearwall Segments table
-
All but
the shear force and capacity information now resides in the Shearline, Wall and Opening Dimensions table.
-
The shear
force and capacity are now listed in the Shear Results tables.
b) Add Seismic Information table
-
Building
mass and storey shear moved here from storey information table
-
Show
storey shear in both force directions
-
Added
length of SFRS (seismic force resisting system) to be used in irregularities
analysis (see B2 above)
-
Added Seismic Irregularities table described
in the Seismic Load Generation section (B2, above), with warnings, notes, and
irregularity list
a) Company and Project Information
-
Now in
form of table
-
Listed
only if company or project information is entered in settings dialog
-
Now
organised into a table
-
Gives full
name and year of design standard, and wind standard clause used ( Fig I-15 or
I-1/8)
-
Add nail
withdrawal moisture content conditions, for fabrication and service
-
Add
anchorage restriction settings
-
Add
dissimilar materials setting
-
Add
setting for height restriction for wind loads
-
Remove
sheathing combination, not relevant to Canada
-
Remove
wind capacity increase, not relevant to Canada
-
Remove
seismic load reduction factor, not relevant to Canada
-
Now
organised into a table
-
Expand
definition of occupancies
-
Wind:
-
Update
design code used
-
Add units
for velocity pressure
-
Add Internal Gust Factor CGi
-
Add Terrain
-
Add Topographic Information section.
-
Seismic::
-
Add
reference to seismic procedure in NBCC used.
-
Remove Seismic Zone, and Zonal Ratio,
-
Replace Soil Category with site class
-
Add Sa(T)
for T = 0.2, 0.5, 1.0, and 2.0
-
Replace Za, Zv with Fa, Fv.
-
Replace R with Ductility Factor Rd and Overstrength
Factor Ro
-
The Building Mass and Story Shear are no longer presented here. They have been moved to
the new Seismic Information
table
-
Location and Extent are now shown for
both directions.
-
Ridge Location and Ridge
Elevation now refer to the absolute values.
-
The
relative values also included as Ridge
Offset and Ridge Height
-
Gives
ridge direction
-
Add legend
explaining headings.
g) Shearline, Wall and Opening Dimensions
-
Added
legend explaining headings
-
Organised
into separate sections for E-W and N-S shearwalls
-
Add
subheadings for line and level
-
Added
column for full height sheathing.
-
Loads now
sorted much better by Block, Load Case, Direction, Location etc,
-
Can be
shown combined (as accumulated by program) or separately (as entered). Separately is default.
-
Removed
level column, as table is organised by levels
-
Added Block and Element columns
-
Low rise
reference corner and wind case are both listed in the Load Case column.
-
The
magnitude column is split into Magnitude
Start and End
-
The
tributary width column is renamed Trib Ht
which better represents the value
-
Added
legend
i) Wind, Seismic Shear Forces (applied directly)
-
Corrected
ragged output
-
Removed
name column, that used to simply contain “Wall”
-
Added Block column. Previously it was unclear
what block the load came from
-
Fixed bug
that reversed the values in the interior and end zones.
k) Dead Loads and Uplift Loads
-
Heading
for these loads did not correspond to data in columns – this has been corrected
-
Corrected
ragged output of rows
-
Separate
columns for start and end magnitude
-
Move
tributary width column
-
Added
legend explaining columns, and building elements
-
Separate
columns for start and end magnitude
-
Remove
level column (table organised by levels)
-
Remove
level column (table organised by levels)
-
Separate
columns for start and end magnitude
-
Added
legend, including explanation of seismic loads as combination of masses on many
elements
-
Added
legend explaining all the columns and data within them, incorporating the notes
that were previously below the table.
-
Add
subheadings for line and level
-
Added
comma between low rise-reference corners to distinguish them
o) Drag strut and Hold-down Forces
-
Added
legend explaining the meaning of the headings and the data within the columns.
-
Changed
dead load to show factored load, to be consistent with shearline force.
-
Added
“Line” subheadings
-
Changed
the heading for the from Holddown Force
[lbs ] to Tensile Holddown Force
[lbs]
-
Added
explanatory notes for vertical elements and for moment arm used in force
calculation.
-
Added
numbered notes for those hold-downs (rather than anchorages) required due to
irregularities
p) Components and Cladding by Shearline
-
Added
legend explaining meanings of headings and data
-
Added
column for service condition factor for moisture conditions
-
Reorganized
into north-south and east-west shearline sections
a) Drag Strut and Hold-down Note
In both the Drag strut and Hold-down Forces table of
the Design Results, and Elevation View, a note has been added to indicate that the user choice in the Design Settings of Applied Load for hold-down and drag strut force has been
over-ridden by Shearwall Capacity for
seismic irregularities due to NBCC 4.1.8.15 (2).
b) Dissimilar Materials in Elevation View (Issue
CSW7-36)
If walls with
dissimilar materials exist on the same shearline, then the program shows the
materials for the strongest wall. Note that this wall may not be composed of
the heaviest materials, due to the affect of the Jhd factor.
There is now also a
note in this view indicating that you should consult the design results for the
materials for each wall on the line.
a) Shear Capacity Results when there are
Non-shearwalls (Bug CSW7-9)
When a shearline
consists of one shearwall and at least one non-shearwall, the Shear Results
table the output was not showing the capacity information Vhd/L, Jhd and V, for
that line.
b) Fastener Spacing Unit Label (Bug 1664)
The units beside the
input for fastener “Inter. Spacing" (field spacing) were displayed as mm,
when the values in the list were in inches.
c) Fastener Penetration Units (Bug 1773)
The fastener
penetration information in the Materials by Wall Group table was always
displayed in millimetres even though it should display in inches when Imperial
units are selected.
d) 75mm Edge Nail Spacing (Bug CSW7-37)
The program was
reporting 75mm edge nail spacing as 70mm. The design calculations were using
75mm.
e) Fastener Information in Elevation View (Bug
1572)
Imperial units
fastener information in Elevation View showed metric nail thickness without
displaying mm, incorrectly showed metric edge spacing, and showed a fractional
value for field spacing that was slightly different than the round number input
into program.
f) Imperial Capacities in Elevation View (Bug
CSW7-24)
Nonsensical values
were showing for elevation view for shear capacity and C&C capacity in the
elevation view material specification, due to unit conversion problems.
g) Shear Capacities for Zero-length Segments (Bug
CSW7-30b)
When shear capacities
differ for different segments, the program was outputting results for
zero-length segments, causing repetition.
h) Header on Printed Design Results (Bug 1167)
The header
information and page numbers were present only on the first page of the design
results printout.
i) Maximum Font Size for Page Width (Bug 1330)
The printed text
output in 10 size font did not completely fit onto the width on regular
letter-size page. It now prints fits with 11 size font.
j) Wind Uplift and Dead Loads Table Headers (Bug
1775)
The headers for wind
uplift loads and dead loads were the same as the ones for building masses, when
they should have headings appropriate to these loads. As a result, the Profile
column was misaligned.
k) Incomplete Design Material Specification
For large,
complicated structures with openings and non-shearwalls, for some shearlines
the Materials table contained "?" for nail spacing or sheathing
thickness.
I: Documentation and File Operations
The on-line help has
been reviewed to make sure it is up-to-date with current program operation and
current design code references.
The Help system used
is now HTML Help, which is compatible with the Windows Vista operating system,
as well as previous versions of Windows.
Extensive Release
notes describing all changes to the program have been added for this version,
in the html file New Features, which
is included with the installation.
d)
Bizarre Font in
Old Operating Systems*
For version 2002, the
content of the Shearwall help file used bizarre Wingding font when Windows 95,
Windows 98 and Windows NT operating systems are being used
The on-line CSA O86 -01
design standard in .pdf format supplied with WoodWorks Sizer has been updated
and includes the January 2003 Update No 1 1 and the January 2005 Supplement.
The on-line design
code now works with the most recent versions of Adobe Acrobat.
A design note has
been added to both the Welcome box and to the Design Results design notes
giving the editions of the NBCC and CSA O86 used in the program. All program
references to design codes have been updated.
a) Opening Files from Previous Versions (Bug 1458) *
Project files from
previous major versions could not be opened with version 2002/2002a in the same
session that a version 2002/2002a file had been opened or saved. Version 7 can
open files from previous versions in all situations.
After many of the
user operations, the program was not indicating to Windows that a project file
had been modified, leading to cases where you could close a file without being
notified to save it. This has been rectified.
Shearwalls 2002a
- October 29, 2004 - Design Office 2002 (Service Release 1)
This Service Release
consisted of a review of all known problems and user issues with Shearwalls and
a resolution to any of these that were significant and/or simple to
resolve.
Bug Fixes and Features Overview
A.
Building
Model and Program Operation
1.
Unexpected
Shut Down
2.
Update of
Joining Roof Configuration
3.
Removal of
Indentations
4.
Wall
Segmentation Shutdown
5.
Interior
Walls Protude outside Building
6.
Merging
Walls - Effect on Roof Joining
7.
Roof
Joining of Abutting Blocks
8.
Wall
Creation for Uneven No of Storeys
9.
Roof
Joining Error for Unusual Configuration
10.
Three-Block
Upper Level Wall Creation
11.
Upward
Extension of Three Block Structure
12.
Roofs on
Three Block Multilevel Buildings
13.
Joined
Roof Panel Slopes
14.
Uneven
Number of Stories
15.
Segmentation
of Middle Block Walls
16.
Roof
Generation on Diagonally Abutting Blocks.
17.
Wall
Height Warning Message
18.
Default
Values Settings
19.
Main Menu
Key Shortcuts
B.
Engineering
Design
1.
Seismic
Design with Unknown Stud Spacing
2.
Negative
Crritical Design Shear Forces
3.
Duplicate
Wall Groups, Exterior Sheathing Only
4.
Duplicate
Wall Groups, Different Hold-down Configuration
5.
Incomplete
Design Material Specification
6.
Wall Group
Number
7.
Extra Wall
Group in Materials Table
8.
Ce on
Windward Walls
C.
Seismic
Load Generation
1.
Seismic
Load Generation on Complicated Structures
2.
Reversal
of Fundamental Period T
3.
Building
Mass of Line of Non-shearwalls
4.
Building
Mass of Intersecting Roof Blocks
5.
Zero Point
Building Masses in Plan View
6.
Upper
Level Wall Building Masses
7.
Metric vs
Imperial Roof Masses
8.
Zero Point
Building Masses in Plan View
D.
Wind Load
Generation
1.
Topographic
Factor
2.
Wall Load
Generation after Roof Move.
3.
Height h
for Ce
4.
Ce on
Gable End
5.
Width of
NBCC Zone 2 Low Rise Loads
6.
Low-rise
Tributary Width
7.
Wind
Pressure on Gable Ends
E.
Load
Distribution
1.
Rigid
Distribution to One Shearline in each Direction
2.
Display of
Manually-entered Wall Rigidities
3.
Vertical
Distribution of Load Combination Factor
F.
Data Input
1.
Unknown
Edge Spacing
2.
Blank
Input Fields for OSB Materials
3.
Default
Tributary Width
4.
Zero
Ceiling Depth
5.
Save as
Default Operation
6.
Effect of
Default Setting
7.
Fit to
Print on One Page
8.
Note when
Resetting View Settings
9.
View Area
and Snap Increment Menu Item
10.
Overhang
Group Box Covered
11.
Data
Visibility in Input Controls
12.
Underscores
in Input Forms
G.
Text
Output
1.
Truncated
Log File
2.
Saving Log
File
3.
Roof
Masses in Design Results
4.
Hill Shape
in Design Results
5.
Above and
Below Escarpment Crest Reversal
6.
Units for
Hold Down and Dragstrut Forces
7.
Direction
Heading in Shear Results Table
H.
Graphical
Output
1.
Elevation
View Layout
2.
Design
Shear on Non-Shearwalls in Elevation View
3.
Shearline
Forces on a Non-Shearwall in Elevation View
4.
Update of
Forces in Elevation View
5.
Hold-down
Symbols in Plan View
Bug Fixes and
Features Details
A.
Building
Model and Program Operation
1.
Unexpected
Shut Down
Shearwalls no longer closes down frequently when creating roofs, segmenting
walls or generating loads.
2.
Update of
Joining Roof Configuration
When the configuration of a roof is changed, the configuration of a roof joined
to that roof is now changed
3.
Removal of
Indentations
The program no longer shuts down when the wall that forms the face of
indentaion or protrusion is moved so as to eliminate the indentation and form a
line with other walls.
4.
Wall
Segmentation Shutdown
Program no longer shuts down on wall segmentation using Wiindows XP operating
system, in particular when you segment wall 2-1 of Quick Start Tutorial of the
user manual.
5.
Interior
Walls Protude outside Building
It is no longer possible to move exterior walls such that interior walls extend
outside of the building
6.
Merging
Walls - Effect on Roof Joining
Merging walls on two abutting blocks caused the blocks to abut rather than
overlap, and the roofs not to join or to be able to be joined manually.
7.
Roof
Joining of Abutting Blocks
For certain configurations, when blocks join but do not overlap, the roof of
the smaller block did not join the larger one.
8.
Wall
Creation for Uneven No of Storeys
For joining blocks with different number of levels, changing wall location
before extension upwards no longer creates disattached walls on the upper
level.
9.
Roof
Joining Error for Unusual Configuration
Attempting to create a structure with at least three blocks arranged so that
the first block contains an entire wall of the second block, and the third
block diagonally abuts the second block, caused the program to hang on roof
creation.
10.
Three-Block
Upper Level Wall Creation
When three adjacent blocks are defined such that the middle block has fewer
levels than the outside blocks, the extension of walls to upper storys no
longer creates walls on the middle block where there is no storey.
11.
Upward
Extension of Three Block Structure
When extending a structure with three colinear blocks of different
levels, all blocks were given the same number of levels.
12.
Roofs on
Three Block Multilevel Buildings
Roof creation no longer fails for center block in three adjacent block
multi-level building with different numbers of levels.
13.
Joined
Roof Panel Slopes
Joined roof panels’ slopes were occasionally set using the wrong connecting
roof panel.
14.
Uneven
Number of Stories
For buildings with uneven numbers of stories, the program would occasionally
shut down when changing views.
15.
Segmentation
of Middle Block Walls
When the external walls of the middle blocks of three or more blocks are
segmented and then moved, gaps between the blocks, such that the blocks become
disjoined, no longer appear.
16.
Roof
Generation on Diagonally Abutting Blocks.
Program no longer shuts down on roof generation for diagonally opposed blocks
that do not overlap.
17.
Wall
Height Warning Message
After decreasing the wall height a warning message appeared even if he wall was
within limits.
18.
Default
Values Settings
The operation of default settings for new files has changed. If no file is
open, all settings automatically are saved for new files. If a new file file is
opened only the Default Values settings are set to Save for New Files. A note
in the settings box indicates those Default Value settings which have an effect
on current file operation.
19.
Main Menu
Key Shortcuts
Several main menu key shortcuts have been repaired. "Alt+I" and
"Ctrl+U" now work for Log File and for User Manual, respectively;
Extend Walls has been changed to Alt+E and Plan View to Alt+P; and Ctrl-P
prints.
20.
Species
when Multiple Walls Selected*
The framing Species field did
not appear blank in Wall Input View
when different wall studs species exist for walls selected simultaneously in Plan View. The value that appeared could
even be one that is not an attribute of any selected wall. This has been fixed
21.
Help File
Font*
The content of the Shearwall help file used unreadable Wingding font
when Window 95, Window 98 and Window NT operating systems were being used. This
affected about 15% of users.
B.
Engineering
Design
1.
Seismic
Design with Unknown Stud Spacing
Walls with unknown stud spacing always failed for seismic design.
2.
Negative
Crritical Design Shear Forces
Negative critical design shear forces were not being considered, causing
incorrect creation of hold-downs and approval of failed walls in design search.
3.
Duplicate
Wall Groups, Exterior Sheathing Only
Multiple wall groups with Identical materials were being generated when walls
had sheathing on exterior surface only.
4.
Duplicate
Wall Groups, Different Hold-down Configuration
Duplicate wall groups with the same material configuration are no longer
created when holdown configuration is different.
5.
Incomplete
Design Material Specification
For large, complicated structures with openings and non-shearwalls, for some
shearlines the Materials table contained "?" for nail spacing or
sheathing thickness.
6.
Wall Group
Number
The Design Group(s) number shown in the Wall Input form is now updated after
running design.
7.
Extra Wall
Group in Materials Table
For wind design only, an extra wall group, which was not used anywhere, was
sometimes being created.
8.
Ce on
Windward Walls
The NBCC Ce factor was too small on gable ends and too large on walls due to
coarseness in the numerical integration routine.
C.
Seismic
Load Generation
1.
Seismic
Load Generation on Complicated Structures
For large buildings containing many indentations and protrusions, the
generation of seismic loads caused the application to shut down.
2.
Reversal
of Fundamental Period T
The calculated N-S and E-W fundamental period T values were reversed, so that
the wrong default values appeared in the Site dialog and would be used to
generate seismic loads if not changed.
3.
Building
Mass of Line of Non-shearwalls
The building mass of shearlines composed entirely of non-shearwalls, is now
being included in generation of seismic building masses.
4.
Building
Mass of Intersecting Roof Blocks
The building mass values shown in the Seismic Iinformation Table no longer
include the overhang on the intersecting portion of two roof blocks.
5.
Zero Point
Building Masses in Plan View
Numerous seismic point building masses were showing up in the plan view drawing
adjacent to building corners.
6.
Upper
Level Wall Building Masses
The wall building mass created for the upper storey was based on the full
height of the wall rather than half the height. However the seismic loads
generated from these masses were based on the correct height.
7.
Metric vs
Imperial Roof Masses
Small differences due to rounding between metric and imperial roof masses have
been eliminated.
8.
Zero Point
Building Masses in Plan View
Numerous seismic point building masses were showing up in the plan view drawing
adjecent to building corners.
D.
Wind Load
Generation
1.
Topographic
Factor
The program was using values in mm rather than m for hill dimensions in NBC
1995, Commentaries B 18; eq. ( 6) page 1, causing app. 10% error in the
topographic factor calculated.
2.
Wall Load
Generation after Roof Move.
After a roof block was unattached from the rest of the roof, the loads for the
walls on that block were not being generated in the same session.
3.
Height h
for Ce
The height h reported in the logfile for NBCC Ce factor for windward walls is
slightly low due to an error in the numerical integration used to calculate it.
4.
Ce on
Gable End
The program was amplifying the NBCC Ce value slightly on the gable end by
averaging over the height as if it was a rectangular surface instead of a
triangle.
5.
Width of
NBCC Zone 2 Low Rise Loads
When applying Note 9 from Figure B-7, NBCC- 95 Com. B the program was
mistakenly moving the dividing line in zone 2 by a small portion of the eave
width.
6.
Low-rise
Tributary Width
When windward roofs are divided according to NBCC Com. Figure B-7, note 9, the
area load tributary width shown in Load Input View for each zone was the entire
roof panel height instead of the heights of the divided zones.
7.
Wind
Pressure on Gable Ends
A too low height h was being used to calculate the NBCC Ce factor on windward
gable ends, resulting in lower than expected
E.
Load
Distribution
1.
Rigid
Distribution to One Shearline in each Direction
Program was attempting rigid distribution to one shearline in each direction,
even though torsional rigidity cannot be calculated in this case. It now
disallows such configurations.
2.
Display of
Manually-entered Wall Rigidities
Removed the e.g ( Wind Design ) from the Wall Rigidities input field for
manualy entered rigidities, and now apply the input rigidity to both wind and
seismic design.
3.
Vertical
Distribution of Load Combination Factor
When shearlines on upper stories did not have any walls directly bellow, in the
flexible distribution method the load combination factor was being re-applied
as the force was distributed from an upper level to the level below.
F.
Data Input
1.
Unknown
Edge Spacing
The "unknown" option was missing from the edge spacing dropdown when
the Restrict materials and override option was set in the Design Setttings,
causing incorrect edge spacing data to appear in the Materials table of the
Design Results
2.
Blank
Input Fields for OSB Materials
For OSB materials, the nail length and stud spacing drop down boxes no longer
appear blank at times.
3.
Default
Tributary Width
Manually entered area wind loads now have default tributary width.
4.
Zero
Ceiling Depth
The default ceiling depth in Structure Input View, is now set to zero instead
of the same value as joist depth.
5.
Save as
Default Operation
In the Settings, the Save As Default checbox was by default not checked when a
file was not open. Now, if a file is not open, this is checked and disabled,
and when a file is open, it is unchecked and enabled.
6.
Effect of
Default Setting
A message now indicates that changing Site information in the Default Settings
does not have an immediate effect on these values in Site Dialog box, but the
wall, opening, and roof defaults do have an immediate effect.
7.
Fit to
Print on One Page
The option "Adjust font size so that text output fits on one page" in
the Format Settings has been removed.
8.
Note when
Resetting View Settings
When "Reset Original Settings" was selected in the View Settings, a
note about choice of unit systems no longer appears.
9.
View Area
and Snap Increment Menu Item
View Area and Snap Increment selections in the View data filter bar no longer
cause Default Values settings to appear rather than View Settings
10.
Overhang
Group Box Covered
Attempt to change roof overhang no longer causes the overhang group box to be
covered by a line.
11.
Data
Visibility in Input Controls
Adjusted size and position of several controls in Wall Input form and Site
Dialog to allow data to be completely visible.
12.
Underscores
in Input Forms
Small underscores that appeared randomly in the text labels of several input
views have been removed.
G.
Text
Output
1.
Truncated
Log File
Log file no longer truncates before reporting of log file data is complete.
2.
Saving Log
File
The log file is now not available when the project is reopened.
3.
Roof
Masses in Design Resutls
The roof masses are no longer listed as zero in the Block Information table of
the Design Results. This was always the case for existing files, and for new
files for some roof panels.
4.
Hill Shape
in Design Results
In the topographic information of the Building Site section of the Design
Results, the Hill Shape is now being shown.
5.
Above and
Below Escarpment Crest Reversal
"Above" and "Below" crest of escarpment are no longer
reversed in the Site Information of the Design Report.
6.
Units for
Hold Down and Dragstrut Forces
In the Design Results, units are now displayed for the Hold Downs and Dragstrut
Forces table.
7.
Direction
Heading in Shear Results Table
East-West section of Shear Results table no longer reads North-South
Shearlines.
H.
Graphical
Output
1.
Elevation
View Layout
Numerous improvements were made to the appearance and readability of the
Elevation View display and printout, such that the elements have appropriate
sizes and do not obscure one another.
2.
Design
Shear on Non-Shearwalls in Elevation View
The design shear was displayed at the base of non-shearwalls in the elevation
view if the non-shearwall was once a shearwall, and would persist after another
design is run.
3.
Shearline
Forces on a Non-Shearwall in Elevation View
After changing the wall type in an entire shearline from shearwalls to
non-shearwalls, the shearline forces were still being displayed in elevation
view after the next design.
4.
Update of
Forces in Elevation View
Forces on the walls are now shown in Elevation View after selecting the
Generate Loads action. Previously, the Load InpuI View had to be selected
before going to Elevation View.
5.
Hold-down
Symbols in Plan View
Symbols for adjacent holddowns on large buildings no longer obscure the display
of force values.
Shearwalls 2002 - November 18,
2002 - Design Office 2002
Version 2002 has had
improvements to Version 99 that are so numerous and extensive that it can be
considered a new program. The following is an index to the new features that
are listed in more detail below.
A.
Installation
Features
1.
New
Keycode system
2.
New
Installation
B.
Building
Model Features
1.
Multi-story
design
2.
Levels
information
3.
Multiple
blocks
4.
Roof
module
C.
Load
Features
1.
New Load
Types and Profiles
2.
Site
information
3.
Wind Load
Generator
4.
Low Rise
Load Cases
5.
Seismic
Load Generator
6.
Building
Masses
7.
Dead loads
and Uplift loads
8.
Load
Accumulation
D.
Design
Forces
1.
Automatic
Load Distribution
2.
Rigid
Diaphragm Method
3.
Flexible
Diaphragm Method
4.
Force
Distribution Along Shearine
5.
Holddown
and Dragstrut Forces
6.
Vertical
Force Distribution and Overturning Forces
E.
Shearwall
Design
1.
Seismic
Design
2.
Leeward/Windward
Wind Design
3.
C&C
Design
4.
New CSA
O86-01 Provisions
5.
Jhd
Factor
6.
Hold-down
Configuration
7.
Iterative
Hold-down Design
8.
Iterative
Design for Dissimilar Materials.
F.
Materials
1.
Material
List
2.
Gypsum
Wallboard
3.
Construction
Sheathing OSB
4.
OSB Grades
and Plywood No. Of Plies
5.
New
Sheathing Thicknesses
6.
Nail Sizes
7.
Nail
Factor Jn
8.
Framing
Species and Species Factor Jsp
9.
Unblocked
factor Jub
10.
Dissimilar
Materials
G.
Design
Results Reporting
1.
New
Sections
2.
Results
Formatting
3.
Load Lists
4.
Design
Notes
5.
Results
Filtering
6.
Log file
H.
User
interface features
1.
Elevation
View
2.
Show menus
3.
New menus
4.
Wall
material input
5.
Graphical
input
6.
Zoom
Feature
7.
Load List
I.
Program
Settings
1.
Default
Settings
2.
Design
Settings
3.
Options
Settings
4.
Loads and
Forces
J.
Bug
Fixes
1.
Wall
Operations
2.
Scrolling
3.
Memory
Leak
Detailed Descriptions:
A.
Installation
Features
1.
New
Keycode system
Refer to the KEYCODE SECURITY section above for details.
2.
New
Installation
Shearwalls is now part of an integrated installation of all the components of
WoodWorks Design Office 2002. Previously, each component was installed
separately
B.
Building
Model Features
1.
Multi-storey
design
Designs up to 4 stories, transferring shear, overturning, dead load, and uplift
forces down through structure. Displays walls from any number of floors in
elevation view.
2.
Levels
information
Foundation elevation, wall heights and floor and ceiling depths for each storey
have been added. The format of the input fields has been made demonstrative of
the structure. It is possible to return and modify these data at any
time.
3.
Multiple
blocks
The program allows input of multiple building blocks for ease of initial wall
creation, roof modelling, different levels in one building, and low rise wind load
generation. The program automatically joins intersecting blocks to create an
exterior shell of walls.
4.
Roof
module
The program automatically creates roofs on each building block, joins the
roofs, and allows the user to change the roof size, position, construction,
slope, ridge location and overhangs.
C.
Load
Features
1.
New Load
Types and Profiles
The user can input wind shear, wind C&C, wind uplift, seismic or dead
loads. These can be point loads, line loads, area loads, trapezoidal loads, or
triangular loads. These are all displayed graphically next to the loaded
building elements.
2.
Site
information
The now contains a dialog box for the input of topographic, climate and
seismologic site information, and building characteristics such as enclosure
and use, for the generation of wind and seismic loads. It calculates
fundamental period T based on the building model.
3.
Wind Load
Generator
The software now generates main wind force resistance system (MWFRS) and
component and cladding (C&C) wind loads on the entire structure or on
specific components using the NBCC 1995 4.1.2 low-rise (Commentary B, Figure B7
) or medium-rise (Commentary B, Figure B14/15 ) simplified procedures.
4.
Low-rise
Load Cases
The program generates all 8 low-rise load cases corresponding to wind at of the
4 windward corners of the building, and Case A or Case B wind directions. It
designs the shearline force resulting from the strongest of these loads per
shearline. You can view each of these cases independently via the display
menus.
5.
Seismic
Load Generator
The software now generates seismic shear loads on the entire structure or any
part of the structure, based on the mass of specific components. It uses the
static analysis from the NBCC 1995 4.1.9 and Structural Commentary J.
6.
Building
Masses
The program automatically generates building masses based on user input self
weights of walls, roof, floors and ceilings for use in seismic load generation.
The users can enter their own building masses.
7.
Dead loads
and Uplift loads
The user can enter dead loads and roof uplift loads, and these will be
transferred down through the structure. The program reports their value at
holddown locations. You can now distinguish wall dead loads from others for use
in hold-down factor Jhd calculations
8.
Load
Accumulation
The loads shown on the screen are the derived by accumulating all the
overlapping loads applied to the diaphragm edge at a building face, so that a
load envelope is achievedSimilarly, vertical loads and masses area accumulated
along shearlines. You can see the loads that were originally input or generated
in the load list.
D.
Design
Forces
1.
Automatic
Load Distribution
User can input wind loads or seismic loads to a building face, and these will
be distributed to the shearwalls by the rigid diaphragm method and the flexible
diaphragm method. The user may add forces manually to adjust the automatically
distributed forces.
2.
Rigid
Diaphragm Method
The program distributes loads to shearwalls using rigid diaphragm method, and
outputs design results based upon these shearwall forces. It examines all 4
torsional load cases described in NBCC 4.1.9.2(28) User can base the relative
rigidity on shearwall strength, or manually enter rigidities.
3.
Flexible
Diaphragm Method
The program distributes loads to shearwalls loads based on tributary width
between shearlines, and outputs design results based upon these shearwall
forces. The assumption is that for irregular structures, drag strut collectors
are present to allow the diaphragms to be oriented in the direction of the
loads in both orthogonal directions.
4.
Force
Distribution Along Shearline
If the user selects to use dissimilar materials along a shearline, the program
distributes the shearline force to each segment based upon the material
resistance of the segment.
5.
Holddown
and Drag Strut Forces
Overturning, dead, uplift components of holddown forces are shown at openings
and wall ends, or the user can choose to combine these. Drag strut forces
are shown at openings and wall ends. Drag struts and holddowns are also
reported in an output table.
6.
Vertical
Force Distribution and Overturning Forces.
The program now takes into account the presence or absence of hold-downs or
anchorages at the top and bottom of each restraint location in determining the
overturning forces and vertical force distribution. It can do this for
special cases such as vertically offset openings.
E.
Shearwall
Design
1.
Seismic
Design
User enters seismic loads and program performs separate force distribution for
them. It designs for these forces separately from the wind loads, and also
reports the design results separately.
2.
Leeward/Windward
Wind Design
User can enter and the program generates leeward wind loads, windward loads, or
loads that apply to either situation. Program designs shearlines for loads in
each direction. It first determines the worst of all low-rise load cases in
each direction.
3.
C&C
Design
C&C Design is be performed for exterior walls that are not designated as
shearwalls, and for shearwalls, the worst case of shear and C&C loads will
govern the design.
4.
New CSA
O86-01 Provisions
The program fully implements all the shearwall design provisions from the new
CSA O86-01, Chapter 9.
5.
Jhd
Factor
The program computes the new Jhd factor described in CSA O86-01 9.4.5. based
upon the presence or absence of hold-downs at the ends of wall segments between
openings, non-shearwalls, or ends of the shearline.
6.
Hold-down
Configuration
The user can specify whether hold-downs are to be at the ends of walls, ends of
segments, or ends of the shearlines in the Wall Materials input.
7.
Iterative
Hold-down Design
The user can instruct the program to over-ride the selection of hold-down
locations in order to achieve a successful design. It strategically adds
hold-downs to increase the Jhd factor until a design is achieved
8.
Iterative
Design for Dissimilar Materials.
If dissimilar materials are chosen, and some materials are unknown, the program
designs the shearwalls, distributes the forces, then repeats this process until
a stable design is achieved
F.
Materials
1.
Material
List
The materials and resistances specified by CSA O86-01 are used, rather than
those listed in the USA Wood Frame Construction Manual.
2.
Gypsum
Wallboard
Gypsum sheathing has been added as a material, as allowed by CSA-O86-01.
The program adjusts the R value used for seismic load generation based upon the
presence of gypsum wallboard.
3.
Construction
Sheathing OSB
This material has been added to the program, using the same shear resistance
values as Design Rated, Type 1 OSB, but with different resistance to C&C
loads. This material is identified by Panel Marking, and the program will
implement the equivalence to thickness.
4.
OSB Grades
and Plywood No. Of Plies
The program now allows input of these parameters, which affect panel strength
in bending and shear-through-section for C&C design.
5.
New
Sheathing Thicknesses
The program will implement the new thicknesses specified by CSA O86-01 for
resistance to shear. These are 11.0 mm and 15.0 mm for OSB and 15.5 mm for
plywood. In addition, 18.5 mm (18.0 mm) is added for resistance to C&C
loads.
6.
Nail Sizes
The program has included input fields for both nail length and diameter, and
has implemented the new provisions basing shear strength on the diameter and
minimum penetration. The program reports nail penetration.
7.
Nail
Factor Jn
The user is allowed to enter non-standard nail sizes and the program implements
the strength calculations described in O86 9.5.1A(5) and Appendix A9.5.1.
8.
Framing
Species and Species Factor Jsp
The new table 9.4.3 for species factor Jsp has been implemented. Glulam, MSR,
and MEL have been added to the list of framing materials. The provisions
regarding MSR and MEL grades have also been added.
9.
Unblocked
factor Jub
The program now allows blocked or unblocked horizontal panels, and implement
the blocking factor Jub for unblocked shearwalls as specified in O86
9.4.4
10.
Dissimilar
Materials
The program implements CSA O86 9.3.3.4, which allows for dissimilar materials
along a shearline. The user can select whether to allow dissimilar materials or
make all the shearwalls in a line have the same materials.
G.
Design
Results Reporting
1.
New
Sections
Sections for design settings, storey information, roof geometry, site
information, and building masses input have been added.
2.
Results
Formatting
Much improved reporting of design results, with separate tables for each type
of input load; wall materials, shearlines; shear results; C&C results; wall
segments, openings, holddown and drag strut forces.
3.
Load Lists
The seismic and wind shear loads listed are the accumulated loads, not those
entered or generated. These are sorted in such a way as to make correlation
with the generated loads easy.
4.
Design
Notes
Numerous design notes referring to specific sections of the CSA O86 -01 or NBCC
have been added to the end of each table indicating any special situations or
where a design code note has been applied.
5.
Results
Filtering
User may choose which tables from which design runs to view or print using the
display menus.
6.
Log file
A log file is output showing intermediate calculations and detailed information
for wind load generation, seismic load generation, and rigid diaphragm design.
The log file can be accessed from the menu
H.
User
interface features
1.
Elevation
View
Elevation view selectively displays shear flow, drag strut forces, holddown
forces, and C&C loads. Sheathing and nailing capacities are displayed next
to the design materials. The user can select to view any number of storeys, and
either force direction along a shearline. The program displays anchorages,
hold-downs, and compression forces with different symbols.
2.
Show menus
Toolbars menus have been added to allow user to show or hide items on the
screen or printed output. The same settings can be viewed and changed all at
once in the settings dialog. The type of loads and forces to be viewed, roofs,
wall names, gridlines, and building masses can all be toggled on and off.
3.
New menus
Right mouse click menus and menus on each window provide quick access to some
of the graphics and design features such as resizing the windows, viewing,
display, and design settings.
4.
Wall
material input
This view has been streamlined somewhat, and the operation has been made more
stable.
5.
Graphical
input
Interactive graphics have been improved, making it easier to select, segment,
resize, and move walls and openings. More tolerance has been added to the mouse
operations.
6.
Zoom
Feature
§ There are now two buttons on the plan view bar,
one for Zoom In and one for Zoom Out. The program increases or decreases the
viewing area by a certain percentage when the buttons are pressed, while
maintaining the same west and south view limits.
§ The percentage that the view is zoomed each
time a button is clicked is specified in the View Settings - the user can
choose a zooming increment anywhere from 1% to 100%.
7.
Load List
The loads listed in the Load Input form now have 8 separate categories
describing there location, direction, load case, etc, and can be sorted by any
one of these categories by clicking on the category.
I.
Program
Settings
1.
Default
Settings
A new default setting page has been created for the existing default dimensions
and the following additions:
§ Initial wind load generation site
information
§ Initial roof geometry
§ Building mass self-weights
§ Floor/ceiling depth
§ Standard walls on top floor and on other
floors.
2.
Design
Settings
Settings have been added for:
§ choosing the wind load generation method,
§ the height used for restrictions on these
methods;
§ rigidity method for rigid diaphragm
analysis;
§ dissimilar or similar materials along
shearline;
§ enabling gypsum wallboard contribution to shear
strength;
§ whether to allow the program to override the
choice of hold-down locations.
§ vertical elevation offset of shearlines
3.
Options
Settings
Settings to turn on and off the display have been added for :
§ Roof outline in other views
§ Design Results tables.
4.
Loads and
Forces
A "tower of settings" has been added to organise the display of
generated, accumulated, and user input loads and forces in plan view, elevation
view, and design results view The form shows which of these interact with each
other and in what way, as many are exclusive. These settings can also be
changed via the Show... menus.
J.
Bug
fixes
1.
Wall
Operations
§ Crash when attempting to segment walls right to
the end of the wall is fixed.
§ Annoying line that appeared when creating the
first wall has been removed.
§ No longer possible to create gaps in exterior
shell of building
2.
Scrolling
§ If the view limits were set to zoom into a
region such that scrolling was necessary to see the whole building, scroll bars
did not necessarily appear, nor did they appear for a CAD import that is bigger
than the view limits. (This was a problem in Windows 95/98 only )
§ When an existing file is opened, or when the
view limits are changed, or when a CAD file is first dimensioned, the program
now sets the position of the scroll bars to the co-ordinates of the view
limits. This way the view that the user sees on the screen exactly corresponds
to the one set in the settings until the user first uses the scroll bar.
3.
Memory
Leak
Using Shearwalls on a Windows 98 machine for a period of time severely depleted
the Windows GDI resources, causing failure of program graphics. This has been
fixed.
First version to
incorporate Canadian design provisions.
1.
Version
now designs according to CSA O86.1-94.
2.
Revised
the Form for entering wall data. The form now displays materials for both sides
of a wall simultaneously. Standard walls are now created and modified on a
separate form.
3.
The
program now prevents you from creating walls of insignificant length.
Version 97b – April 22, 1998
1.
Imported
CAD drawing information is now saved in the project file so that when a file is
re-opened the CAD drawing is automatically imported.
2.
A message
box now appears if you attempt to draw more than one block in the Block Action.
3.
The snap
increment is now displayed and saved in inches. This should solve problems with
round-off that prevented users from decreasing the snap increment.
4.
An
Examples folder containing a 7-step example has been added. The online
Help contains a description of the steps.
5.
Wall
selection with the mouse pointer has been improved.
6.
An endless
loop where the message "Opening cannot exceed past end of the wall"
was displayed has been fixed.
7.
The
imported CAD file can now printed.
Initial version of
program used provisions from USA Wood Frame Construction Manual. Program had the following capabilities
·
Input of
one rectangular block, and convert that block to shearwalls
·
Input of
one building level only
·
Reconfiguration
of exterior walls, maintaining closed envelope
·
Input of
interior walls
·
Input of
wall materials, including unknowns to be designed by Shearwalls
·
Input of
openings in shearwalls
·
Automatic
shearline generation using “bandwidth” approach
·
Input of
point forces directly on shearlines
·
Design
shearwalls using WFCM provisions
·
Calculation
and display of hold-down forces
·
Design,
view and display settings and options
·
Project
info and company info input
·
Elevation
view output showing forces and design materials for a shearline
·
Rudimentary
design results report
·
Print and
print preview of all graphics and reports.