Wind and Seismic Stresses

The AISC ASD specification permits allowable stresses due to wind or earthquake forces, acting alone or in combination with dead and live load, to be increased by one-third (Art. 6.11). The required section computed on this basis, however, may not be less than that required for the design dead, live, and impact loads computed without the one-third stress increase. This stress increase cannot be applied in combination with load-reduction factors in load combinations. Also, the one-third stress increase does not apply to stresses resulting from fatigue loading.
In LRFD design, equivalent allowances are made by the prescribed load factors when appropriate.

Scroll to Top