钢桁连续梁人行桥人致振动研究

Study on Human Induced Vibration of Steel Truss Continuous Girder Pedestrian Bridge

本文以某跨度为(78+150+78)m的大跨连续钢桁梁人行桥为工程背景,基于通用有限元软件建立桥梁模型并分析了其动力特性,参照国内相关规范模拟了步行荷载通过桥梁的工况,获取了桥梁的人致振动响应,基于舒适度评判标准讨论了在天桥跨中安装调谐质量阻尼器(TMD)的减振效果。结果表明:①桥梁动力响应随着人群密度的增大而增大;②当人群密度达到4.6人/m2时,桥梁竖向的行人舒适度已处于不合格区间,侧向的行人舒适度仍处于合格区间内;③通过舒适度结果对比,采用TMD可以有效控制人行天桥的竖向振动,减震效果显著。

Taking a long-span continuous steel truss pedestrian bridge with a span of(78+150+78)m as the engineering background,based on the general finite element software,the bridge model is established and its dynamic characteristics are analyzed.According to the relevant domestic codes,the walking load through the bridge is simulated and the human induced vibration response of the bridge is obtained.Based on the comfort evaluation criteria,the vibration reduction effect of TMD installed in the span of overpass is discussed.The results show that:1)the bridge dynamic response increases with the increase of population density,2)when the crowd density reaches 4.6 persons per m2,the vertical pedestrian comfort of the bridge is in the unqualified range,while the lateral pedestrian comfort is still in the qualified range,3)through the comparison of comfort results,TMD can effectively control the vertical vibration of pedestrian overpass,with significant damping effect.