桥梁地震需求分析中建模不确定性的敏感性研究  

Sensitivity investigation of modeling uncertainty for seismic demand analysis of bridges

作　　者：吴文朋[1,2,3] 李立峰 唐盛华[1,3] 张旭辉[1,3] WU Wenpeng;LI Lifeng;TANG Shenghua;ZHANG Xuhui(College of Civil Engineering and Mechanics,Xiangtan University,Xiangtan411105,China;College of Civil Engineering,Hunan University,Changsha410082,China;Key Laboratory of Dynamics and Reliability of Structures,College of Hunan Province,Xiangtan University,Xiangtan411105,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]湖南大学土木工程学院,长沙410082 [3]工程结构动力学与可靠性分析湖南省高等学校重点实验室,湖南湘潭411105

出　　处：《振动与冲击》2018年第24期257-264,270,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金项目(51508488; 51708477);湖南省高等学校重点实验室开放课题(KZ070010101)

摘　　要：为探讨桥梁建模相关不确定性对结构地震需求的影响,促进基于性能的桥梁抗震设计方法在实际工程中的应用,以一座4×30 m的钢筋混凝土连续梁桥为例,考虑材料(Material Uncertainty,MU)、边界(Boundary Uncertainty,BU)和结构(Structural Uncertainty,SU)三类桥梁建模相关的不确定性,基于Open SEES程序建立多参数化有限元动力分析模型,输入22条标准化的远场地震波进行非线性时程分析,根据分析结果进行概率条带分析,并基于龙卷风图对各种不确定性进行了敏感性研究。结果表明:随着地震动强度的增加,影响结构地震需求预测的建模不确定性因素越多;建模不确定性对构件响应均值(μ)和对数标准差(ζ)的影响不完全相同; SU对所有的工程需求参数(Engineering Demand Parameter,EDP)都有较大影响,但BU的影响却因EDP的不同而不同;相比SU和BU不确定性的影响,MU不确定性的影响相对较小。In order to explore the impact of bridge modeling uncertainties on the seismic demand and improve the application of performance-based seismic design of bridges in practical engineering,a reinforced concrete continuous bridge consisting of four30m spans was taken as a case study.The OpenSEES software was applied to build a multiple dimension parameterized finite element model considering the uncertainties derived from structural material,boundary and the structure itself.Twenty two standardized far-fault ground motions were used to conduct the nonlinear time-history analysis.Based on the analysis results,the probabilistic stripe analysis method and the tornado diagram were adopted to investigate the sensitivity of various uncertainties.It is concluded that,the number of uncertainty parameters that affect the seismic demand prediction of the bridge is increased with earthquake intensity.The impact of the modeling uncertainties on the mean value(μ)and logarithmic standard deviation(ζ)is not consistent.Structural uncertainties have great impact on all engineering demand parameters,while the impact of the boundary uncertainty is dependent on different engineering demand parameter.Compared to the impact of the structural and boundary uncertainties,the impact of the material uncertainty is relatively less.

关 键 词：桥梁工程 地震需求 条带分析 建模不确定性 敏感性 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]