基于向量IM的钢筋混凝土桥墩地震易损性分析  

SEISMIC VULNERABILITY ANALYSIS OF REINFORCED CONCRETE BRIDGE PIERS BASED ON VECTOR-VALUED INTENSITY MEASURE

作　　者：李宁[1] 李杨[1] 李忠献[1] 

机构地区：[1]天津大学滨海土木工程结构与安全教育部重点实验室,天津300072

出　　处：《工程力学》2016年第1期58-63,71,共7页Engineering Mechanics

基　　金：国家重点基础研究发展计划(973计划)项目(2011CB013603);国家自然科学基金项目(91315301;51427901;51378341);天津市应用基础与前沿技术研究计划项目(13JCQNJC07200)

摘　　要：该文基于向量形式的地震动强度度量参数(Intensity Measure,IM),建立了一种预测钢筋混凝土(RC)桥墩损伤水平的地震易损性分析方法。以某城市桥梁为研究对象,考虑桥梁结构本身的不确定性以及地震动的不确定性,采用基于向量IM的易损性曲面对RC桥墩进行了地震易损性分析,对不同损伤状态下RC桥墩的易损性进行了研究。研究表明:由于地震荷载的复杂性,在进行RC桥墩地震易损性分析时,标量IM往往会忽略地震动的其他重要特性。向量IM因其包含了更多的地震动信息,能够显著地降低对于RC桥墩损伤水平预测的离散性,因而具有重要的研究价值。与传统标量IM形成的易损性曲线相比,该文提出的基于向量IM的易损性曲面可以有效地反映第二个地震动强度度量参数引起的RC桥墩易损性失效概率的变化。因此,采用向量IM进行RC桥墩的地震易损性分析能够更加准确地对RC桥墩的抗震性能做出评估。This article presents a method for the seismic vulnerability analysis of RC piers, which predicts the damage levels of RC piers by using vector-valued intensity measures（IM）. An urban bridge is taken as the analysis model. Considering the uncertainties of the bridge and ground motions, seismic vulnerability analysis of the RC pier is performed using vector-valued IM. Then, fragility surfaces of the RC pier for different damage states are studied. The research results indicate that, taking into account the complexity of the seismic excitation, the scalar IM tends to neglect some important characteristics of ground motion when conducting the seismic vulnerability analysis of the RC pier. However, vector-valued IM contains more ground motion information and it can reduce the dispersion in the prediction of damage levels of the RC pier effectively, which will be very important in seismic analysis. Compared with the fragility curves formed using scalar IM, the fragility surfaces deduced from vector-valued IM can better reflect the variability of the vulnerability failure probability of the RC pier caused by the second intensity measure parameter. Thus, when vector-valued IM is used in the seismic vulnerability analysis of the RC pier, it can more accurately evaluate the seismic performance of the RC pier.

关 键 词：地震动 易损性曲面 不确定性 向量烈度指标 钢筋混凝土桥墩 

分 类 号：U442.55[建筑科学—桥梁与隧道工程] U443.22[交通运输工程—道路与铁道工程]