Standard Shear Walls - The Analysis of Irregular Shaped Structures - page 360

F i g u r e 9.24 Drag strut framing, option 2.

9.9 Shear Wall and Foundation Issues

Two common mistakes are made in doing the calculations necessary to check the over-
turning stability, foundation reinforcement, and soil-bearing pressure at the founda-
tion. The first mistake occurs when the lateral force is applied at the top of the shear
wall without transposing the forces from the top of the shear panels, at the diaphragm
level, to the top of the shear wall below. The second mistake occurs by not summing the
moments about the bottom of the footing to determine the soil-bearing pressures.

Example 9.6: Shear Wall Foundation Design
A foundation will be designed for the shear wall in Example 9.5. Assume that a 2′-0″ wide
footing, extending 1 ft on each end of the shear wall, is desired as shown in Fig. 9.26. The
total dead load of the roof, wall, and footing has been calculated to be 11,820 lb, centered
on the wall and footing.

Allowable soil-bearing pressure = 2000 psf 1.33 increase allowed for wind or

seismic per soils report