型钢混凝土框架结构地震易损性数值模拟研究

Seismic fragility of SRC structures based on Open SEES and IDA

基于地震工程模拟平台Open SEES,研究了型钢混凝土(SRC)框架的数值建模方法。根据试验结果对比了3种不同非线性梁柱单元模型的计算效果,确定了最优单元模型。基于Open SEES平台和增量动力分析(IDA)方法研究了型钢混凝土框架结构的地震易损性。设计了3个具有不同柱梁抗弯承载力之比的结构,对其进行IDA分析,获得了各模型的抗震能力曲线。根据结构抗震能力曲线,求解了结构的地震易损性曲线,得到了结构在地震作用下各性态点的超越概率。对场地地震危险性进行分析,获得了场地地震危险性概率模型。基于结构地震易损性曲线及场地地震危险性概率模型,计算了结构各性态点的年平均超越概率。结果表明:柱梁抗弯承载力之比对计算结果的影响显著,随着柱梁抗弯承载力之比的增大,结构在特定地震动作用下倒塌的概率呈减小趋势。

Based on the open system for earthquake engineering simulation - OpenSEES, the modeling of the steel reinforced concrete （SRC） frame structure was put forward. Compared with the test results, the computational accuracy of the three different beam-column elements was determined. With reference to OpenSEES and incremental dynamic analysis （IDA）, the seismic fragility of SRC structure was investigated. Three SRC frames with different ratios of column-to-beam strength was designed and calculated to obtain the structural seismic capacity curve. The structural seismic fragility was analyzed according to the calculated structural seismic capacity curve, and the excee- ding probability of the different state levels was obtained. The probability model for the ground seismic hazard was established through ground seismic hazard analysis. Based on the calculated fragility curve and probability model for the ground seismic hazard, the annual exceeding probability of different state was derived. The results show that the ratio of column-to-beam strength has great influence on structural seismic fragility. The increase of the ratio of column-to-beam strength can effectively reduce the collapse potential of the structure.