Two Strength Design Approaches.

The strength design procedure for tall, slender walls is found in Section 9.3.4.4 of TMS 402-22 and in Section 9.3.5.4 of TMS 402-16 and TMS 402-13. This procedure requires that the engineer accounts for P-delta effects. This can be done in one of three ways. The first is a step-function analysis, which is iterative. The second allows the use of a second-order analysis, such as that used in some software. The third is a moment magnifier method that is less cumbersome than the step-function method but can also be more conservative. This article reviews the step-function method and the moment magnification method.