基于PSDM和IDA方法的桥梁地震易损性模型参数比较分析

以汶川地区一座典型三跨简支梁桥为例,基于OpenSees平台建立全桥三维非线性基准有限元模型.在考虑地震动及结构参数不确定性基础上,对抽样生成的桥梁样本进行了一系列非线性地震响应分析,分别采用PSDM和IDA方法分别建立桥梁构件及系统的地震易损性模型.介绍了易损性模型参数的物理意义,对不同方法计算得到的地震易损性分析结果展开模型参数比较研究,分析探讨了结果的差异原因及既有方法改进措施.

Model parameter comparison of bridge seismic vulnerability based on PSDM and IDA methods

Taking a typically simply supported girder bridge in the Wenchuan region as an example, a 3D baseline nonlinear finite element model of the bridge structure was built by OpenSees platform. A set of nonlinear seismic response analyses for the bridge samples were preformed in which the uncertainty of ground motion and bridge parameters are considered, and the seismic vulnerability models of the bridge components and system were built by PSDM and IDA methods. The physical interpretations of the vulnerability modal parameters were introduced. The model parameters of the seismic vulnerability results by different methods were compared, and the causes of difference and improvement measures were analyzed and discussed.