Research On Practicability Of Pushover Analysis Procedure In The Building Structures

The highly unpredictability of earthquake and the great casualties and economic losses caused by the recent earthquakes promote the development of the seismic design theory. Along with performance-based seismic design’s appearance and development, Pushover analysis, as a simplified method to design and analyze performance, has aroused interests in academics and engineers and has been extensively studied. This method is a simple and effective way to evaluate the seismic structures, which avoids the complicated nonlinear dynamic analysis and also provides good accuracy. Therefore, this method has a significant value not only in theoretical research but also in engineering practice. This paper takes steel frame structure as an example to discuss Pushover analysis in engineering practice.This paper introduces the performance-based seismic design theory, domestic and international research statu of Pushover analysis and summarizes the advantages and disadvantages of Pushover analysis. Secondly, this paper discusses the basic principles of Pushover analysis. And focuses on the capacity spectrum method, the displacement coefficient and the MPA (modal pushover analysis) method.The lateral force patterns and higher modes influence are also given in a detailed discussion and comparison because they have a significant impact on the results.This paper describes how to use the analysis software SAP2000to achieve static and dynamic elasto-plastic analysis and parameter selection and applies SAP2000and Pushover analysis to a12-story steel frame structure. By using Pushover analysis, the12-story structure is analized to get X and Y direction static elasto-plastic results, under15different load combinations. These results are compared with the results under the effect of P-△, and a comprehensive assessment to the sturcture seismic performance is obtained. In case of three different natural seismic waves, results in Y direction of the12-story steel frame structure are obtained by using the dynamic elasto-plastic analysis. Some practical conclusions are drawn from comparision between results from dynamic elasto-plastic analysis and results from Pushover analysis.