Research On Seismic Performance Factors Of RC Frame Structures Based On FEMA P695

The American raised a set of probabilistic seismic performance evaluation method in FEMA P695 report.The structure designed in accordance with the global seismic performance parameters of American current seismic design code is evaluated to affirm whether the structure can meet the expected resistance collapse performance targets.It is of great theoretical significance and practical value for improving the scientific, reasonable and economical of our country structure resistance design to adopt the method to evaluate the implied overall seismic performance coefficient and the ability to resist earthquake collapse of the structure accordance with the current seismic design code.Focused the research object on the common reinforced concrete frame structure, 9 typical reinforced concrete frame structures are designed with different layers and different intensity, strictly accordance with the current seismic design code.By Etabs and Perform- 3D program, structural system archetypes are developed and nonlined analysis are also performed. According to the result of analysis, all structural seismic performance coefficients and the adjusted collapse margin ratio are confirmed, then seismic evaluation for a whole structure is performed based on the FEMA P695. The main contents of the paper are as follows:1) 9 RC frame structures are analyzed with nonlinear static(pushover) analysis method. According to the results of the analysis, structure response modification coefficient R,the overstrength factor0?,the ductility factor T? and the deflection amplification factordC are calculated and their variation laws are offered.2) 9 RC frame structures are analyzed for incremental dynamic analysis(IDA). Then according to the analysis result, median collapse intensity CTS, the collapse margin ratio CMR are calculated and collapse fragility curve is confirmed by practical method.Based on the basic period of structures and the ductility factorT?, spectral shape factor SSF and the adjusted collapse margin ratio ACMR are confirmed and their change rules with seisimic intensity and structure layer are offered.3) Based on the design requirements-related collapse uncertainty,the test datarelated collapse uncertainty, the modeling-related collapse uncertainty and the record-to-record collapse uncertainty, total system collapse uncertainty is computed. Then the seismic performance of the overall structures is performed based on the FEMA P695.The evaluation result suggested that RC frame structures designed according to the current seismic design code of buildings meet the design requirements of “not collapse in severe seisimic”in the structural seismic performance evaluation based on FEMA P695, but the design code is generally tend to be conservative, so it is advised to appropriately improve structure response modification coefficient R implied in our country code.