跨灞河慢行桥人致振动舒适度分析

Comfort Analysis of Human-induced Vibration at Bahe Slow Bridge

对于大跨径的轻柔桥梁结构,由于其自振频率较低,在行人激励荷载下更容易发生大幅振动,引起行人舒适度的问题。因此,以西安国际港务区跨灞河慢行桥工程为背景,结合国内外人行桥设计规范,利用有限元软件Midas civil建立该桥3D模型,对该桥中竖向振动频率在人行荷载频率敏感范围内的结构进行人致振动时程分析,并根据行人激励荷载作用下的竖向振动加速度时程曲线以及模态分析结果,设计相应的TMD减振系统,使结构振动加速度满足相关舒适度要求。研究结论对类似桥梁减振设计具有一定的参考价值。

Due to the low natural vibration frequency,the soft bridge structure with long spans is more likely to have large vibration under pedestrian excitation load,which causes the problem of pedestrian comfort.Therefore,based on the Bahe Slow Bridge project in Xi'an International Port Area,combined with domestic and foreign footbridge design norms,the 3D model of the bridge is established by finite element software Midas civil to carry out the human-induced vibration time history analysis of the structure with vertical vibration frequency within the sensitive range of pedestrian load frequency.According to the vertical vibration acceleration time history curves and modal analysis results of pedestrian excitation load,the corresponding tuned mass damper(TMD)vibration damping system is designed to make the structure vibration acceleration meet the relevant comfort requirements.The conclusion of the study has certain reference value for the design of similar bridges.