加劲钢桁连续刚构桥地震易损性分析

Seismic Vulnerability Analysis of Stiffened Steel Truss Continuous Rigid Frame Bridge

为研究高速铁路加劲钢桁连续刚构桥的结构抗震性能,以一座(97+2×108+97)m加劲钢桁连续刚构桥为工程背景,借助有限元软件MIDAS Civil,通过纤维截面划分实现非线性,建立全桥有限元模型,采用增量动力分析(IDA)方法计算背景桥梁在地震作用下的动力响应,并据此建立各构件及全桥地震易损性曲线。结果表明:该桥抗震性能良好,满足规范要求;在各损伤状态下,系统的损伤概率相较于构件均会有不同程度的增长;在进行结构的抗震性能评估时,仅从单个构件角度进行分析是偏安全的,还需考虑系统内各构件之间的相关性。

In order to study the seismic performance of a high-speed railway continuous steel truss bridge,a(97+2×108+97)m continuous steel truss bridge was studied by Midas the nonlinear finite element model of the whole bridge is established by civil finite element software.The incremental dynamic analysis(IDA)method is used to calculate the response law of the structure under different earthquake intensities,and the seismic vulnerability curves of each component and the whole bridge are established by combining with logarithmic regression analysis.The results show that the seismic performance of the bridge is good and meets the requirements of the code.When considering the safety of the whole bridge system under earthquake,we should not only pay attention to the damage of each component,but also pay attention to the damage relationship between components.