结构不确定性对高速铁路矮塔斜拉桥概率地震需求的影响  

Influence of structural uncertainty on probabilistic seismic demand of high-speed railway extradosed cable-stayed bridge

作　　者：谢明志[1] 杨永清[1] 庄重 黄胜前[1] XIE Mingzhi;YANG Yongqing;ZHUANG Zhong;HUANG Shengqian(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Chengdu Construction Co.,Ltd.,Chengdu 610000,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]成都建工集团有限公司,四川成都610000

出　　处：《铁道科学与工程学报》2022年第6期1475-1484,共10页Journal of Railway Science and Engineering

基　　金：四川省科技计划资助项目(2020YJ0081,2021YJ0054);中央高校基本科研业务费科技创新项目(2682021CX011,2682017CX007);国家重点研发计划项目(2017YFC0806007);广西科技计划项目(2021AA01007AA)。

摘　　要：为研究结构不确定性对高铁矮塔斜拉桥概率地震需求影响,以怀邵衡铁路沅江大桥(90+180+90) m的矮塔斜拉桥为研究对象,基于随机参数概率分布,考虑混凝土材料相关性,采用拉丁超立方抽样方法建立地震动-桥梁样本。通过OpenSees软件建立非线性动力时程模型,并采用增量动力分析方法计算、对比分析并明确不确定性与确定性对矮塔斜拉桥概率地震需求的影响,探明桥梁地震需求与随机参数的关系。研究结果表明:支座摩擦因数、混凝土容重、核心混凝土峰值应变、核心混凝土峰值抗压强度、阻尼比、结构尺寸、非核心区混凝土的应变和强度是影响高速铁路矮塔斜拉桥概率地震需求的敏感参数。纵横向地震作用下,索塔曲率和梁端转角变化异于其他地震需求参数。结构不确定性对该桥概率地震需求分析影响显著,将梁端转角作为地震需求参数,为探明高速铁路桥梁地震功能损伤分析提供依据。充分考虑结构不确定性因素影响,是保障桥梁地震易损性分析准确可靠的基本前提,对厘清桥梁地震损伤具有理论及实践意义。In order to study the influence of structural uncertainty on the probabilistic seismic demand of short tower cable-stayed bridges for high-speed railways,theextradosed cable-stayed bridge(90+180+90) m of the Yuanjiang River Bridge of the Huaishaoheng Railway was used as the research object,and a Latin hypercube sampling method was used to establish ground vibration-bridge samples based on random parameter probability distribution and by considering concrete material correlation.The nonlinear dynamic time history model was established by OpenSees software,and the incremental dynamic analysis method was used to calculate,compare,analyze and clarify the effects of uncertainty and certainty on probabilistic seismic demand of extradosed cablestayed bridge,and to explore the relationship between the seismic demand and random parameters.The results show that friction coefficient of bearing,concrete bulk density,peak strain of core concrete,peak compressive strength of core concrete,damping ratio,structure size,strain and strength of non-core concrete are sensitive parameters affecting the probabilistic seismic demand of high-speed railway extradosed cable-stayed bridge.Besides,the influences of the pylon bottom curvature and main girder angles are different from other seismic demand parameters under longitudinal and transverse direction earthquake.The structural uncertainty has a significant impact on probabilistic seismic demand analysis of the bridge,and the main girder angle can be taken as the seismic demand parameter to provide a basis for the seismic function damage analysis of high-speed railway bridges.Therefore,fully considering the influence of structural uncertainties is the basic premise to ensure the accuracy and reliability of bridge seismic vulnerability analysis,which has theoretical and practical significance to clarify the bridge seismic damage.

关 键 词：桥梁工程 高速铁路 矮塔斜拉桥 结构不确定性 概率地震需求 

分 类 号：U24[交通运输工程—道路与铁道工程] U448.27[建筑科学—桥梁与隧道工程]