地震作用下钢管混凝土组合桁梁-格构墩轻型桥梁行车安全性分析  

Analysis on Running Safety on Lightweight Bridge with CFST Composite Truss Girder and Lattice Piers under Earthquakes

作　　者：黄育凡 吴庆雄[1,2] 袁辉辉 陈宝春[1] HUANG Yu-fan;WU Qing-xiong;YUAN Hui-hui;CHEN Bao-chun(School of Civil Engineering,Fuzhou University,Fuzhou Fujian 350116,China;Fujian Provincial Key Laboratory on Multi-disasters Prevention and Mitigation in Civil Engineering,Fuzhou Fujian 350116,China;Key Laboratory of Engineering Structure of Fujian Province University,Fuzhou Fujian 350116,China)

机构地区：[1]福州大学土木工程学院,福建福州350116 [2]福建省土木工程多灾害防治重点实验室,福建福州350116 [3]工程结构福建省高校重点实验室,福建福州350116

出　　处：《公路交通科技》2018年第11期77-86,共10页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51608125; 51678154; 51508104)

摘　　要：为研究地震作用下钢管混凝土组合桁梁-格构墩轻型桥梁的行车安全性,以干海子特大桥为研究对象,建立考虑地震作用的车桥耦合振动方程,并将计算方法添加到基于梁单元的双重非线性有限元程序NL_Beam3D中,实现地震作用下车桥系统相互作用的耦合计算。考虑车辆倾覆指标和桥梁横向变形的影响,进行行车安全性分析。结果表明:有限元计算得到的基频和不同车速下最大动挠度与实桥荷载试验得到的结果接近;与已有振动台试验结果相比,位移时程曲线形状吻合,位移幅值满足相似比关系,验证了计算模型和方法的有效性。柔性高墩轻型桥梁对地震波有滤波效应,地震波传至桥梁时强度明显减弱;最不利的重型货车的倾覆指标阈值大于E1多遇地震时的桥面最大横向加速度,即不存在车辆侧倾现象;墩顶位移满足设计要求,干海子特大桥行车安全性能良好。部分墩顶横向位移在地面峰值加速度达到1. 6倍E1多遇地震动时,将超过《公路钢管混凝土桥梁设计与施工指南》给出的限值。桥面最大加速度在地面峰值加速度为2倍E1多遇地震动时,倾覆指标阈值小于桥面最大横向加速度,重型货车存在倾覆可能;对应的桥墩墩顶最大横向位移与墩高比例系数达1/198,大于指南限值1/300,说明该指南对桥墩墩顶位移限值规定相对比较保守。To study the running safety of lightweight bridge with CFST composite truss girder and lattice piers under earthquake,taking Ganhaizi Bridge as the research object,the vehicle-bridge coupled vibration equation considering earthquake is established,and the calculation method is added into the double nonlinear finite element program NL_ Beam3 D based on the beam element to achieve the vehicle-bridge coupling calculation under earthquake. The running safety is investigated considering the influence of the vehicle overturning index and bridge transverse deformation. The result shows that（ 1） the fundamental frequency and the maximum dynamic deflection calculated by finite element method are close to those obtained by the load test of the real bridge;（ 2） compared with the shaking table test result,the shape of displacement timehistory curve is consistent,and the displacement amplitude satisfies the similarity ratio relationship,whichverified the effectiveness of the finite element model;（ 3） the lightweight bridge with flexible high piers can filter from the ground motion,which is obviously weakened when it is transmitted to the bridge deck,（ 4）under the E1 ground motion,the maximum transverse acceleration of bridge deck is less than that of the most unfavorable heavy truck,which means there is no rollover hazard on the vehicle running on the bridge;（ 5） the displacement on the top of pier meets the design requirements,and the running safety performance of the bridge is well;（ 6） when PGA is 1. 6 times as much as E1 ground motion,the transverse displacement on the top of several piers exceed the limitation given in Guide to Design and Construction of Road CFST Bridge;（ 7） when PGA is 2 times as much as E1 ground motion,the maximum transverse acceleration of bridge deck exceeds the roll threshold,the heavy trucks may turnover when passing;（ 8） The ratio of the maximum transverse displacement on the top of piers to the pier height is 1/198,which is greater than the design limitation 1/30

关 键 词：桥梁工程 行车安全性 车桥振动 轻型桥梁 地震作用 钢管混凝土组合桁梁 格构墩 

分 类 号：TU442.5[建筑科学—岩土工程]