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These settings affect the generation of hold-down and compression forces from shear forces on shear resisting element.
Hold-down offset
Here you specify the value of the hold-down offset, that is, the distance between the end of a wall segment and where the hold-down force is situated or the force at the compression end is assumed to act.
These offsets are used to calculate the moment arm used for overturning calculations and for the calculation of shear wall deflection due to the rotation caused by vertical displacement of the hold-down device.
If Calculate for each standard shear wall segment is selected, this input applies only to walls of the type Proprietary/non wood and the program calculates the hold-down and compression force offsets for each standard wood shear wall segment in the structure.
If a value is entered or calculated that is greater than or equal to ½ a shear wall segment length, the program reverts to the original default value of 1.5”, for that segment only. 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.
Calculate for Each Standard Shear Wall Segment
If this check box is selected, then the hold-down offset is calculated for each segment on a standard wood shear wall, separately for the tension end and the compression end. For Proprietary/non-wood shear walls, the input hold-down offset is always used.
The distance at the tension end is the width of the end studs as entered in Wall or Opening input view, plus the hold-down anchor bolt center line offset, which comes from the hold-down database for the selected hold-down.
The distance at the compression end is one-half the width of the end studs, i.e. the center of the end stud pack.
Include joist depth…in moment arm calculation
This checkbox indicates whether the program includes the floor depth above the wall in the wall height h when calculating the overturning moment arm.
SDPWS 4.3.6.1.2. Eqn. 4.3-8 and the definition of h in SDPWS 2.3 indicate that the joist depth is not included, however this creates gaps in the static analysis of multi-level structures. The default value of this setting to not add the joist depth as per SDPWS, but you can change this with Save as default for new files.