优化藤Copula的桥梁结构系统地震易损性分析  

Assessment on seismic fragility of bridge structural systems by optimized vine Copulas

作　　者：李幸钰 雷鹰[1] 林树枝 刘丽君[1] Li Xingyu;Lei Ying;Lin Shuzhi;Liu Lijun(Xiamen University,Xiamen 361005,China;Jimei University,Xiamen 361021,China;Xiamen Municipal Transportation Bureau,Xiamen 361001,China)

机构地区：[1]厦门大学,福建厦门361005 [2]集美大学,福建厦门361021 [3]厦门市交通运输局,福建厦门361001

出　　处：《土木工程学报》2023年第11期43-55,136,共14页China Civil Engineering Journal

基　　金：国家自然科学基金(52178304);国家重点研发计划(2017YFC1500603)。

摘　　要：为在桥梁结构系统易损性中更好地考虑不同构件个体之间的相关性,文章提出一种新的优化藤Copula分析桥梁结构系统易损性的方法。该方法与现有的考虑构件类别之间相关性的桥梁系统易损性分析不同,是将桥梁系统包含的各个构件的易损性作为藤Copula函数中的一个变量。通过不同构件个体的地震需求样本间的秩相关系数,基于最短哈密顿路径方法筛选优化的藤Copula函数。从而避免大量的联合概率密度函数的求解以及信息判定准则的试算。同时,提出优化藤Copula函数是基于构件易损性补集的联合概率密度函数(PDF),通过其分析桥梁系统易损性仅需构建一个联合PDF,可避免求解构件不同组合情况下较多的联合PDF。选用四跨有桥台混凝土桥梁结构模型,用桥梁剩余能力模型模拟桥梁的损伤,用提出的方法分析具有桥墩桥台和支座共10个构件个体相关性的桥梁系统易损性,并与目前通常采用的考虑构件类别之间相关性的桥梁系统易损性分析以及Monte Carlo(MC)方法的结果对比,验证提出方法的有效性。In order to better consider the correlation between different components in the bridge system fragility,a new method for seismic fragility assessment of bridge structural system with optimized vine Copula function is proposed in this work.Different from the existing fragility analysis methods considering the correlations of component types,the fragility of each component contained in the bridge system is taken as a variable of the vine Copula function in the proposed method.Based on the rank correlation coefficients of seismic demand samples of different components,the vine Copula function is optimized by the shortest Hamiltonian path approach,so that the a lot of estimations on joint probability density functions(PDF)and trial calculation of information decision criteria may be obviated.Moreover,the proposed optimized vine Copula function is a joint probability density function constructed from the complement functions of component fragility.Hence,the bridge system fragility can be analyzed by establishing only one joint PDF without the necessity of many joint PDFs under different combinations of structural components.A four⁃span concrete bridge structure model with abutment is selected and the residual capacity model is used to simulate structural damage.Based on the proposed method,the fragility of the bridge system with correlations of ten individual components of pier,abutment and bearing in the bridge system is analyzed,and then the analysis results are compared with those obtained by MC method and the traditional fragility method considering the correlation of component types.

关 键 词：地震易损性 桥梁结构 藤Copula 系统易损性 

分 类 号：TU375[建筑科学—结构工程]