|
|
|
|
|
Important Note – These are descriptions to changes implemented in WoodWorks Shearwalls for version 10.0 and may not reflect current behavior
The new 0.6 ASD load combination factor is applied to C&C loads when used for sheathing strength and nail withdrawal design.
In agreement with all other loads shown in plan view, the unfactored C&C load is shown.
In the elevation view output, the word “Unfactored” has been added to indicate that the C&C load shown has not been factored.
The loads shown in the C & C table of the design results have been factored by the 0.6 factor.
Shearwalls needs only the leeward (suction) C&C pressure for both sheathing strength and nail withdrawal design, because the leeward coefficient in Fig 30.4-1 is always larger than the windward one for the small areas considered, and interior pressures are the same in both directions. However, 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.
Shearwalls now shows both 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.
Both the leeward and windward pressures are now shown in elevation view.
The worst of leeward and windward pressures are used for sheathing design. Only leeward pressures are used for nail withdrawal. In ordinary circumstances, that is if loads are generated on all surfaces, leeward pressures are always used for design.
For buildings greater than 60 ft in height, the reference height used for calculation of windward velocity pressure coefficient Kz is the actual height at the top the level in question, rather than the mean roof height. This applies to both external and internal pressures. Note that wood buildings that tall are rare, and that the reduced C&C load on lower levels does not tend to govern because of the accumulated shear forces on lower levels, so this change as little effect.
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.