基于Gaussian Copula的木结构古建筑多准则地震易损性分析

Multi-criteria Seismic Vulnerability Analysis of Ancient Timber Architecture Based on Gaussian Copula

为了解决木结构古建筑不同失效模式之间相关性的问题,基于Copula函数提出考虑结构不同失效模式之间相关性的木结构古建筑地震易损性分析方法.以一座中国明代古建筑为研究对象,首先,根据该建筑的结构特性和相关历史震害资料,选取层间位移角和榫卯节点转角作为地震需求参数.运用Ansys对其进行增量动力分析,建立结构在不同失效模式下的地震易损性曲线.其次,通过建立样本数据的二维频率直方图来选取适宜的Copula函数,进而获得考虑不同失效模式相关性的综合易损性曲线.再次,运用一阶界限法建立结构的易损性曲线.结果表明:基于Copula函数得到的结构易损性大于任何一个失效模式下的结构易损性;其计算结果,小于一阶界限法的上界,略大于一阶界限法的下界.

To consider the correlations among different failure modes of ancient timber architecture,based on Copula function,a new seismic vulnerability analysis method was proposed by taking a Chinese ancient architecture of Ming Dynasty as the study case.First,according to the structural characteristics and historical earthquake damage data of ancient timber architecture,inter-story displacement angle and rotation angle of mortise and tenon joints were chosen as seismic demand parameters and the incremental dynamic analysis method was used to build the vulnerability curves of the structure for different failure modes.Second,based on the incremental dynamic analysis results,two-dimensional frequency histogram was drawn to select the appropriate Copula function.Based on Copula function,the vulnerability curves that consider the correlation of different failure modes were established.Finally,the first-order bound method was used to build vulnerability curves of the structure.Results show that the vulnerability of timber architecture based on Gaussian Copula function is the greatest.The seismic vulnerability of the ancient timber architecture ranges in the upper and lower boundary of the first-order bound method.