A Multimode Pushover Procedure for Asymmetric Buildings Under Biaxial Seismic Excitation

Abstract

In this chapter, a new multimode pushover procedure is presented in order to achieve an approximate estimation of structural performance of asymmetric buildings under biaxial seismic excitation. The steps of the proposed methodology are quite similar to those of the well-known modal pushover analysis. However, the properties of the equivalent single-degree-of-freedom (E-SDOF) systems are modified properly, in order to take into account multidirectional seismic effects. The main scope of this methodology is to avoid additional errors introduced by simplified superposition formulas adopted by codes. In addition, a reduction of the computational cost as compared to other multimode procedures is achieved. After a brief outline of the theoretical background, the sequence of steps needed for the implementation of the proposed methodology is presented. Finally, the accuracy of the proposed methodology is evaluated by an extensive parametric study, which shows that, in general, it provides a useful and conservative design tool.