下挂式人行桥由于交通荷载引起的舒适性分析

Analysis on Comfort of Lower Suspended Footbridge Caused by Traffic Load

将人行道下挂在两幅主桥之间,这种设计方法在国内尚属首次应用,下挂结构刚度较小,由主桥的交通荷载引起的振动直接影响了行人的舒适感和安全感,因此这类人行桥的舒适性问题需要特别的研究。该文采用车桥耦合振动,通过大量数值模拟分析研究由于车辆过桥时引起的人行桥的振动响应。结果表明在良好路面条件下,当车辆(重车)少于10辆/侧时,人行桥的舒适性基本满足要求。路面平整度对舒适性有很大的影响,行车速度对人行桥的舒适性影响不明显。

The footbridge is suspended between two main bridges.This design method is firstly used in China.The rigidity of suspended structure is smaller.The vibration caused by the traffic load of main bridge will directly impact the comfortable feeling and security feeling of the pedestrians.Therefore,it is required to specially study the comfortable issue of this footbridge.Using the coupling vibration of vehicle and bridge,the article analyzes and studies the vibrating response of footbridge caused by the vehicles passing bridge according to a large number of numerical simulations.The result sows that the comfort of footbridge basically satisfies the requirements when the vehicle number(heavy vehicle) is less than 10 vehicles / side under the good condition of pavement.The pavement smoothness greatly impacts the comfort,but the driving speed does not obviously impact the comfort of footbridge.