基于概率密度演化的连续刚构桥抗震可靠度  

Seismic Reliability Analysis of Continuous Rigid Frame Bridge Using Probability Density Evolution Method

作　　者：刘章军[1] 熊敏[1] 万勇[1] 

机构地区：[1]三峡大学水利与环境学院,湖北宜昌443002

出　　处：《西南交通大学学报》2014年第1期39-44,共6页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金资助项目(51278282;50808113);湖北省教育厅自然科学研究重点项目(D20111206)

摘　　要：地震动无论是时间分布还是空间分布都具有很强的随机性,对于长大桥梁结构的随机地震反应与抗震可靠度分析,需要考虑地震动的时间和空间特性,才能较全面地反映桥梁结构的动力反应性态.采用非平稳地震动随机过程的正交展开模型,结合概率密度演化理论,对某连续刚构桥在一致激励和非一致激励下的随机地震反应与抗震可靠度进行了分析.研究结果表明,长大桥梁结构在一致激励与非一致激励下的抗震可靠度存在明显差异,按墩顶位移控制失效准则的抗震可靠度的相对误差可达50%,而按墩顶弯矩控制失效准则的抗震可靠度的相对误差则高达200%.In engineering practice, ground motion has strong randomness in time and spatial distributions. In order to capture accurately the seismic response behavior of long-span bridge structures, the randomness of earthquake excitation should be considered in dynamic response and reliability analyses. By using the orthogonal expansion model for non-stationary ground motion processes and combining the probability density evolution theory, the random seismic response and reliability analyses of a continuous rigid frame bridge are researched under uniform excitation and non- uniform excitation. The research results show that the seismic reliability of long-span bridge structures under uniform excitation and non-uniform excitation are obviously different. When pier top displacement control is used as failure criteria of the seismic reliabilities under uniform excitation and non-uniform excitation, their relative error is up to 50% , and when pier top moment control as failure criteria, their relative error is up to 200%.

关 键 词：连续刚构桥 概率密度演化方法 地震动随机模型 非一致激励 可靠度 

分 类 号：U442.55[建筑科学—桥梁与隧道工程] U448.23[交通运输工程—道路与铁道工程]