Studies On Performance-Based Seismic Response Analysis Method For The Steel Frame Structure

Structural failures in recent earthquakes have exposed the weakness of current design procedures and shown the need for new concepts and methodologies for the seismic performance evaluation of structures. On the basis of the requirements, performance-based seismic design was developed which address life safety, control damage in minor and moderate earthquakes, and prevent collapse in a major earthquake. It can be achieved mainly by two different performance-based seismic designs: one is Static Pushover Analysis, the other is Incremental Dynamic Analysis.In this dissertation, based on the research of the former scholars, the author improves and applies the non-linear Static Pushover for the steel frame structures. Morever, the author studys the method of Incremental Dynamic Analysis and apply this method to the seismic performance of structures.In the Static Pushover analysis, basic concepts and different application methods of the static nonlinear pushover analysis are summarized,some key problems of the static nonlinear Pushover analysis are improved, that is, the instantaneous adaptive lateral load pattern is gained by the internal force of the structure and the target displacement is obtained by combining the capacity spectrum method with the code response spectrum. After analyzing several examples with the program of SAP2000, it is certified that properly chosing lateral load patterns according to the structural dynamic performance is able to reasonably capture the structual response attributes.Incremental Dynamic Analysis (IDA) is the nonlinear time-history analysis in essence. By choosing suitable ground motion intensity measures and representative structural measures, it involves subjecting a structural model to a suit of ground motion records, thus producing a suit of IDA curves of response parameterized versus intensity level. In addition, proper sum-marization techniques for multiple records need to be employed, providing the means for estimating the probability distribution of the structural demand given the seismic intensity.IDA is resourse-intensive. The IDA can be related to the computationally simpler Static Pushover (SPO), enabling an approximation to be established for single-of-freedom systems. By investigating systems with quadrilinear backpones and summarizing the results into a few empirical equations, a new software tool, SPO2IDA, allows direct assessment of demand and capcity.