基于LHS-MC方法的矮塔斜拉桥地震风险概率分析  

ANALYSIS OF SEISMIC RISK PROBABILITY ASSESSMENT OF LOWER-TOWER CABLE-STAYED BRIDGE BASED ON LHS-MC METHOD

作　　者：谷音[1] 郑文婷[1] 卓卫东[1] 

机构地区：[1]福州大学土木工程学院,福州350108

出　　处：《工程力学》2013年第8期96-102,110,共8页Engineering Mechanics

基　　金：国家自然科学基金项目(51108088);福建省自然科学基金项目(2010J01287)

摘　　要：提出一种既能避免繁琐积分,又能综合考虑结构材料和地震波动随机性问题以及地震危险性的地震风险概率计算方法。基于结构材料参数的概率分布,采用拉丁超立方抽样(LHS)方法考虑结构构件材料参数的随机性,并结合选取的地震波,形成地震动-桥梁组合样本集。针对典型矮塔斜拉桥结构体系建立非线性有限元纤维模型,确定各主要构件的损伤指标,与增量动力分析方法相结合进行了地震易损性分析,选取合适的分布函数,拟合加速度峰值-结构损伤概率曲线。采用蒙特卡罗(MC)抽样方法离散地震危险性概率模型,避免了繁琐的积分,针对典型矮塔斜拉桥的地震风险概率进行了评估。A method is proposed to calculate seismic probabilistic risk considering the randomness of the material and the seismic wave, and the seismic hazard. It avoids the cumbersome integration simultaneously. Based on the probability distribution of the structural material parameters, a method of Latin Hypercube Sampling （LHS） is adopted to consider the randomness of the material parameters of the structural members. A sample set of ground motion - bridge combination is formed according to the selected seismic waves. A nonlinear finite element fiber model for the typical short-tower cable-stayed structural system is established. The damage index of the key components is identified. The seismic fragility analysis of lower-tower cable-stayed bridge is carried out with incremental dynamic analysis （IDA）, and the PGA-structural damage probability function is fitted. Monte Carlo sampling methods is used for discretion of seismic hazard probability functions, which avoids the cumbersome integration. The seismic probabilistic risk assessment is made for a typical lower-tower cable-stayed bridge.

关 键 词：地震风险概率 拉丁超立方抽样 蒙特卡罗抽样 增量动力分析方法 矮塔斜拉桥 

分 类 号：TU399[建筑科学—结构工程]