Factors Applied to Shear Line Forces

The loads that you input or those that are generated by the wind load generation or seismic load generation processes are assumed to be unfactored (specified) loads. The program applies factors for wind and earthquake loads as it converts applied loads to shear line forces.

Additionally, the program creates forces for deflection and/or story drift analysis that use the strength-level combinations. These forces are not displayed on the plan view or elevation view screens, but are output in the Design Settings table, the Deflection table and Hold-down Displacement table of the Design Results.

The load combination factors applied are

Strength level force distribution used for seismic deflection for force distribution for consistency with SDPWS assumptions in C.4.3.2 regarding 3-term and 4-terrn deflection equations. ASD forces used for wind design in the absence of other guidance and on recommendation from AWC.

Additionally, when applicable, for seismic design the the program applies the redundancy factor when creating shear line forces. This is determined after the shear walls are designed, so the shear line forces may change by a factor of 1.3 from the loads originally distributed to the shear lines to those that appear after design. You can also set the redundancy factor permanently in the Site Information dialog.

The shear line forces used for drag strut force calculations include the effect of the seismic overstrength factor from discontinuous shear lines on the level above, and under specific circumstances, an irregular structure increase of 25%.

For perforated shear walls, the perforation factor is applied to drag strut forces, hold-down forces, and wall anchorage forces. These are applied on a wall-by-wall basis, not to the whole shear line.