Optimization Approach to Uniformly Distributed Peak Interstory Drifts along Building Heights

Abstract

This study developed a seismic design approach, which has no need of additional structural members, to uniformly distribute the peak interstory drift ratios along building heights. The generalized building model (GBM), which can effectively imitate a building, was used to reach this aim. The flexural-shear deformation factor of a GBM, α, characterizes the deformation type of the corresponding building. Varying the deformation type of a building changes the distribution of the peak interstory drift ratios among stories. Therefore, the proposed optimization approach searches for the optimal value of α, αopt, so that the GBM’s normalized variation of peak interstory drift ratios is minimized. In response to αopt, the member properties of the original building model are adjusted. One nine-story steel moment-resisting frame was used as the example building in this study. The elastic response spectrum analysis results showed that the peak elastic interstory drift ratios of the optimized building were less varied among stories compared with the original building. In addition, 13 of 20 nonlinear response history analysis results were consistent with the trends observed from the elastic response spectrum analyses. As a result, the effectiveness of the proposed optimization approach on the investigated building was confirmed.