Analysis Of Capacity-spectrum Method Considering High Modes Of Tall Wall-frame Structure

With the development of modern society and economy, increasing attention is paid to the attractive appearance and the using function diversification of architectural structure, which leads to the building with irregular section plane becomes routine. So capacity-based seismic design method is unable to meet demand for the diverse structural seismic performance. In order to meet the demands of the times, the scholars of all nations study on performance-based seismic design and achieve gratifying results.This article briefly describes the concept of performance-based seismic design, results of research and development, elaborats on three kinds of displacement-based seismic design method and the capacity spectrum method built in static Elasto-plastic analysis receives general welcome as the advantages of its simple concept, easy to use practicability and so on.Traditional capacity spectrum method only considers the seismic action under basic vibration of structure and is unable to estimate the contribution of high-vibration to seismic response of the structure. However,the internal force and displacement is determined by the vibration models of any orders. So the effects of high-vibration to long-period cannot be ignored, particularly, and if not take it into consideration,it will directly affects the accuracy of results of static pushover analysis.In order to make the seismic design method perfect, the modal Pushover analysis method is introduced on the basis of the past capacity spectrum method and elaborate the principle in detail. Meanwhile, improve it combined with the capacity spectrum method so that the nonlinear static analysis method can not only retain the benefit of capacity spectrum method of conceptual simplicity but also overcome the defect of capacity spectrum method ignoring the high-vibration effects.