Theory Study And Improvement Of Static Elastic-plastic Pushover Analysis Method

This paper describes the development ,the background, basic assumptions, the foundations of theory and the application scope of static elastic-plastic Pushover analysis method and discusses several current existing Pushover analysis methods in detail ,except that ,compares the advantages and the shortcomings of every methods mentioned above and points out the problems among them. Based on the discussions above and aimed at the shortcoming of not considering the effect of high level modes enough, this paper proposes an improved modal Pushover analysis method. In this method, the consideration of the appropriate selects of reasonable numbers of modes and the adoption of the basic principles of the type modal decomposition method and the elastic-plastic response spectra considering strength reduce coefficient make the analysis results even near the actual performances of structures in big earthquake. In the end, the method is verified by one 10 stories frame structures, and the structural seismic performances are also evaluated. The analysis results show that the results of this method are very near that of time history analysis. It proves that this method is an acceptable method. But this method still exists some shortcomings such as: while adopting displacement-control analysis method how to estimate the structural displacement requirement, how to select the horizontal load mode before and after the structure yields, how to considerate the high level mode that have a large effect while it is in the later position ,how to considerate the elastic-plastic response spectra correctly. These problems remain to be solved. So this method needs to improved furtherly.