A QUASISTATIC ANALYSIS METHOD TO IMPROVE COLLAPSE MECHANISM ANALYSES OF MULTISTORY BUILDINGS

摘要

This study proposes a quasi-static analysis method to improve the reliability of conventional collapse mechanism analyses of multi-story buildings. This method is based on the hypothesis that the incremental deformations of the buildings subjected to earthquakes are proportional to the eigenvectors evaluated by using equivalent story stiffness and damping. In this method, the incremental displacements proportional to the eigenvectors are accumulated in the story drifts of the buildings; the eigenvectors are estimated by performing modal analyses whenever an inelastic event occurs in the stories. The analytical results indicate that the conventional pushover analysis generally overestimates the first story drift, while the quasi-static method tends to give good agreements with the results evaluated by the time history analysis.