斜腿刚构曲线连续梁人行桥人致振动风险研究  

Risk estimation of pedestrian induced vibration of curved continuous beam footbridge with inclined leg

作　　者：周涛[1,2] 陈谨林 牛华伟 孟杰[2] ZHOU Tao;CHEN Jinlin;NIU Huawei;MENG Jie(College of Civil Engineering,Central South University,Changsha 410075,China;TY.Lin International Engineering Consulting(China)Co.,Ltd.,Chongqing 401121,China;Vibration and Shock Technology Research Center of Hunan University,Hunan University,Changsha 410082,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]林同棪国际工程咨询(中国)有限公司,重庆401121 [3]湖南大学振动与冲击技术研究中心,湖南长沙410082

出　　处：《铁道科学与工程学报》2021年第9期2358-2365,共8页Journal of Railway Science and Engineering

基　　金：重庆市院士牵头科技创新引导专项资金资助项目(CSTC2019YSZX-YCYJX009)。

摘　　要：大跨度斜腿刚构曲线连续梁钢结构人行桥具有结构轻柔的特点,其基频一般处于人致振动敏感频率范围内,加之主梁采用钢结构材料,结构的阻尼也较低,在行人荷载作用下,桥梁有发生共振的风险。通过介绍行人荷载基本理论和德国人行桥设计指南EN03规范关于人致振动分析方法以及舒适度评价的规定,基于MidasCivil软件建立大桥的有限元仿真分析模型。研究结果表明:该桥有3阶主梁竖弯模态需要进行人致振动加速度响应验算,主梁侧弯模态的频率由于超出了横向人致振动敏感频率范围而不需要验算;在人群荷载作用下,主梁的竖向振动最大加速度达到4.349 m/s^(2);当在跨中设置调谐质量阻尼器(TMD)且质量比取为0.02时,主梁人致竖向振动的最大加速度可降为0.161 m/s^(2),满足CL1等级的舒适度要求。最后,讨论了质量比和TMD频率偏差对减振效果的影响,为同类人行桥调谐质量减振系统参数的选择提供参考。The long-span curve continuous steel beam footbridge with diagonal leg is one kind of soft structures.Its basic frequency is generally within the range of human induced vibration sensitivity frequency.In addition,the structure damping is low because of the use of steel materials.Under the action of pedestrian load,the bridge has the risk of resonance.This paper introduced the basic theory of pedestrian load and the regulations of EN03 code on the analysis method of human induced vibration and comfort evaluation.Based on MIDAS civil software,the finite element simulation model of the bridge was established.The results show that the acceleration response of three bending modes need to be checked and calculated.The frequency of the lateral bending mode of the main beam is beyond the sensitive frequency range of the lateral human induced vibration.Under the action of crowd load,the maximum vertical vibration acceleration of main beam reaches 4.349 m/s^(2).When TMD is set in the span and the mass ratio is 0.02,the maximum acceleration of vertical vibration can be reduced to 0.161 m/s^(2),which meets the comfort requirements of CL1 level.Finally,the influence of mass ratio and TMD frequency deviation on the vibration reduction effect is discussed,which provides reference for the selection of parameters of the same kind of bridge tuned mass damping system.

关 键 词：斜腿刚构曲线连续梁人行桥 人致振动 舒适度评价 振动控制 调谐质量阻尼器 

分 类 号：TU997[建筑科学—市政工程]