Simplified dynamic inelastic analysis of tall buildings

Since the Kobe and Northridge earthquakes, static inelastic analysis has become an accepted and simple method for the seismic evaluation of high-rise buildings. In this method, the lateral load is monotonically increased with the same profile to find the ultimate capacity of the structure. Pushover analysis, however, has a limitation in the evaluation of a higher-mode dominant structure: for this reason, inelastic time history is used to compensate. In engineering practice, using inelastic time history analysis to evaluate the inelastic capacity of a building is impractical for tall buildings owing to the amount of computational time required and the difficulties in interpreting results. Therefore, a simplified inelastic analysis method is required for practical application. In the present paper, a simplified dynamic inelastic analysis (SDIA) method using elastic and inelastic response spectrums is introduced as a way to perform an inelastic analysis of a structure. The relative accuracy and efficiency of SDIA are explored by comparing the results with those of time history analysis software, DRAIN-2DX. The results of SDIA and DRAIN-2DX are almost identical, while with SDIA the computational time is dramatically reduced and time-consuming efforts interpreting results are saved.