摘要
针对桥梁结构构件常用地震易损性分析方法的不足,提出桥梁构件地震易损性分析的核密度估计方法。基于结构地震易损性条件概率的基本定义,重新定义易损性函数,采用概率统计中的非参数估计的核密度估计思想,实现地震动和抗震需求的联合概率密度分布函数、地震动边缘分布概率密度函数的估计,据此构建桥梁结构构件地震易损性的核密度估计算法。用Bootstrap重抽样方法验证所提易损性算法的正确性和可靠性。以一座刚构-连续组合体系桥梁为例,结合桥梁结构抗震设计规范,构建基于OpenSees软件平台的有限元模型,考虑结构参数不确定性和地震动的不确定性,基于增量动力分析和核密度估计,分析桥梁构件的地震易损性。同时分别用结构易损性分析参数估计的最大似然估计法和概率地震需求分析法、非参数估计的蒙特卡罗法计算结构地震易损性曲线,对比讨论4种结构地震易损性分析方法的结果,验证所提方法的正确性和可靠性。研究结果表明:相同计算精度条件下,所提桥梁结构地震易损性分析的核密度估计方法具有较好的计算效率,可用于桥梁结构构件的地震易损性分析中。
In allusion to the shortcomings of seismic vulnerability analysis methods commonly used in bridge structures, an algorithm based on the kernel density estimation for the seismic vulnerability analysis of the bridge component was proposed. Based on the basic definition of the conditional probability for structural seismic vulnerability, the vulnerability function was redefined. The assumption that the lognormal distribution of the vulnerability condition probability was discarded, and no assumptions were made for the relationship between seismic demand and capacity of the component in bridge structure. In light of the nonparametric estimation idea of the kernel density estimation in the probabilistic statistic discipline, the estimation of the joint probability density distribution function for the seismic intensity, seismic demand and the estimation of the probability density function for the marginal distribution function of the seismic intensity were achieved. Furthermore, the algorithm of kernel density estimation for the seismic vulnerability analysis of the bridge structural component was constructed accordingly. The validity and reliability of the vulnerability algorithm was verified by Bootstrap sampling method. Taking a certain rigid frame-continuous composite bridge as an example, its finite element model was established by dint of the OpenSees software platform in line with the current specification of bridge seismic design. Considering the uncertainty of structural parameters and the ground motion, the seismic vulnerability of the bridge component was analyzed based on the incremental dynamic analysis and kernel density estimation. Moreover, the maximum likelihood estimation and probabilistic seismic demand analysis of the parameter estimation methods and Monte Carlo simulation of the nonparametric methods for structural vulnerability analysis were adopted as well to figure out the seismic vulnerability curves. The seismic vulnerability curves obtained from these four methods of structural seismic vuln
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2017年第12期71-80,共10页
China Journal of Highway and Transport
基金
国家重点基础研究发展计划("九七三"计划)项目(2013CB036300-2)
国家重点研发计划项目(2016YFC0802202)
国家自然科学基金项目(51678489)
四川省科技计划项目(2016JY0130)
关键词
桥梁工程
桥梁结构
地震易损性分析
非参数估计
核密度估计
BOOTSTRAP法
对比分析
bridge engineering
bridge structure
seismic vulnerability analysis
nonparametric estimation
kernel density estimation
Bootstrap method
comparative analysis
