基于构件的RC连续梁桥地震体系易损性分析

Seismic Fragility Methodology for RC Continuous Bridges Based on Components Correlation

摘要:

提出了考虑各构件（桥墩、支座、桥台）地震响应相关性的体系易损性计算方法.首先利用均匀设计得到56个结构地震样本对，得到各构件的地震响应；其次通过Matlab计算得到联合概率地震需求模型(JPSDM)，并计算出对应的各构件能力样本；最后借助蒙特卡洛抽样(MCS)得到桥梁结构体系易损性曲线.以一座3跨连续梁桥的非线性Opensees模型为例，结果表明不考虑构件相关性的体系易损性会带来较大误差.

Abstract:

A new method for system fragility is proposed in this paper with consideration of the seismic correlation of bridge fragments (piers, bearings, abutments). Firstly, 56 structure earthquake sample pairs are obtained by uniform design, which are used to get the seismic responses of components. Secondly, the joint probabilistic seismic demand model (JPSDM) is established by Matlab. Then the corresponding capability for each component are calculated. Finally, the bridge structure system fragility curve can be obtained with Monte Carlo Sampling (MCS). The nonlinear Opensees model of a three span continuous girder bridge is established as a case study. The results prove that larger errors will be brought in if the component correlation in fragility analysis is not considered.