Comparison Of The Base-isolated And Fixed-base Structure Based On Probabilistic Assessment

Current research on base-isolated framework is very much.The conclusion that the baseisolated framework is better than the fixed base framework is always drawn under certainty analysis.In this paper,in order to study the seismic behavior of reinforced concrete structure based on the probability under the rare earthquake or the earthquake that is stronger than it,three kinds of base-isolated framework and the one fixed are design according to the latest code for seismic design of buildings(GB 50011-2010).Using SeismoStruct modeling for the reinforced concrete structure,then selecting 22 seismic wave that the ATC-63 recommended to make incremental dynamic analysis(IDA),vulnerability analysis and the analysis of structural collapse resistance.The research work and achievement are as follows:1 ? It is researched that comparing the seismic performance of the base-isolated framework and the fixed with considering the isolation layer collision or not.Then the fixed base framework and base-isolated framework with the different isolating groove width do the incremental dynamic analysis(IDA)to get the IDA curve,according to which it is easy to know that the seismic performance of the base-isolated framework is better than the fixed base framework whether the isolation layer collision is considered or not.2?The vulnerability analysis for fixed base framework and base-isolated framework is researched.The vulnerability analysis according to the result of the incremental dynamic analysis is used for getting the vulnerability curve,then compare the failure probability of the base-isolated framework and the fixed with considering the isolation layer collision or not.Finally,this paper research that the isolating groove width impact on the seismic performance of the same framework with the other isolating groove width.The failure probability of base-isolated framework is less than the fixed under the small seisms.3?Introducing a new evaluation index-Collapse Margin Ratio(CMR)to evaluate the seismic collapse resistance ability,Then comparing the fixed base framework and baseisolated framework with considering the isolation layer collision or not.It is found that the seismic collapse resistance ability of the fixed base framework is better.