Evaluation of seismic performance of multistory building structures based on the equivalent responses

The prediction of inelastic seismic responses and the evaluation of seismic performance of a building structure are very important subjects in performance-based seismic design. Currently, the inelastic time history analysis method and the pushover analysis method such as the displacement coefficient method (FEMA-273) and the capacity spectrum method (ATC-40) can be adapted to evaluate the seismic performance of a building structure. However, the pushover analysis methods have some drawbacks in estimating the accurate inelastic seismic responses. In this study, an improved analytical method based on the equivalent responses of multistory building structures is proposed to estimate the inelastic seismic responses efficiently and accurately. The proposed method can be used to accurately evaluate the seismic performance not only for the global inelastic behavior of a building but also for its local inelastic seismic responses. In order to demonstrate the accuracy and validity of the proposed method, inelastic seismic responses estimated by the proposed method are compared with those obtained from other existing methods. When the proposed method is applied in the pushover analysis more improved analytical results could be obtained than those from the conventional capacity spectrum method (CSM).