不确定性对钢筋混凝土桥梁系统地震易损性的影响  

Influences of uncertainties on system seismic fragility for the reinforced concrete bridges

作　　者：吴文朋[1,2,3] 李立峰 徐卓君[3] 张旭辉[1] WU Wenpeng;LI Lifeng;XU Zhuojun;ZHANG Xuhui(College of Civil Engineering and Mechanics,Xiangtan University,Xiangtan 411105,China;National Joint Engineering Research Laboratory for Long-term Performance Improvement Technology for Bridges in Southen China(CSUST), Changsha 410014,China;College of Civil Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]湘潭大学土木工程与力学学院,湖南湘潭411105 [2]长沙理工大学南方地区桥梁长期性能提升技术国家地方联合工程实验室,湖南长沙410014 [3]湖南大学土木工程学院,湖南长沙410082

出　　处：《地震工程与工程振动》2018年第6期161-170,共10页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金青年项目(51708477);长沙理工大学南方地区桥梁长期性能提升技术国家地方联合工程实验室开放基金项目(16KF02)~~

摘　　要：桥梁工程是由多个构件组成的结构体系,地震作用下不同构件的损伤都可能破坏桥梁的使用功能,而系统地震易损性分析提供了一种评估桥梁整体抗震性能的有效途径。以一座四跨钢筋混凝土连续梁桥为例,选取了26个桥梁建模相关的不确定性参数,并基于OpenSEES程序建立了参数化的有限元模型,同时考虑输入地震波的不确定性后进行一系列的非线性时程分析。然后,考虑桥墩、铅芯橡胶支座、板式橡胶支座和桥台四类构件的地震损伤,研究了各种不确定性对不同构件地震响应、概率地震需求模型(PSDM)、构件以及系统地震易损性的影响。研究结果表明,地震波和桥梁建模相关的不确定性对单构件地震响应的影响较大但规律不一致;构件地震易损性曲线无法反映桥梁建模相关不确定性的对结构整体抗震性能的影响;忽略桥梁建模相关不确定性会在一定程度上导致轻微和中等损伤状态下的桥梁系统失效概率被低估,但在严重损伤和完全破坏状态下桥梁建模相关不确定性对系统易损性曲线的影响可以不予考虑。Bridge engineering is a structural system consisting of various components. The service function of the bridge would be interrupted because of the earthquake damage for different components. The system seismic fragility analysis method provides an efficient approach to evaluate the seismic performance of the whole bridge. A reinforced concrete bridge with four equal spans is taken as an example. Twenty-six bridge modeling related uncertainty parameters are adopted to build the parameterized finite element model by using the OpenSEES software. Meanwhile, the uncertainty of ground motions is also considered to conduct a series of nonlinear time-history analysis. Then, the earthquake damage of the bridge pier, lead rubber bearing, plate-type elastomeric bearing and abutment are considered, in order to investigate the influence of various uncertainties on component seismic response, probabilistic seismic demand model(PSDM), the component and system seismic fragility curves of the bridges. It is concluded that, the component seismic response is affected seriously by uncertainties related to the ground motions and bridge modeling, but the influence law is different. The component seismic fragility curves cannot reflect influences of bridge modeling uncertainty on structural performance as a whole. The system failure probability of the bridge will be underestimated to some extent at the slight and moderate damage status due to ignoring of the bridge modeling uncertainty. However, it is no need to consider influences of bridge modeling uncertainty on system seismic fragility curves at the severe and complete damage status.

关 键 词：桥梁工程 地震 系统易损性分析 建模 不确定性 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]