风荷载作用下大跨度悬索桥的动力响应及列车运行安全分析

建立了风-列车-桥梁体系动力分析模型,根据实测空气动力参数和颤振导数模拟产生抖振力和自激力时域随机风荷载作为输入激励,以一座大跨度悬索桥方案为例,分析了风作用下桥梁和车辆的动力响应。结果表明:悬索桥的横向、扭转位移由风力控制,竖向位移主要由列车重力加载引起。风对桥上列车的运行安全有很大影响:在平均风速为30~40m/s的脉动风作用下,车辆的轮重减载率、脱轨系数和倾覆系数超标,必须给予足够的重视。

DYNAMIC RESPONSE OF LONG SPAN SUSPENSION BRIDGE AND RUNNING SAFETY OF TRAIN UNDER WIND ACTION

A dynamic analysis model of wind-train-bridge system is established.The wind excitations of the system are the buffeting and self-excited forces simulated in time domain using measured aerodynamic coefficients and flutter derivatives.The proposed formulations are then applied to a long suspension bridge.The dynamic responses of the bridge and the train under wind action are analyzed.Results show that the lateral and rotational displacements of the bridge are dominated by wind,while the vertical displacement results from the train’s gravity loading.The running safety of the train is much affected by wind: Under the wind of 30-40m/s,the offload factors,derail factors and overturn factors of the train vehicles exceed the allowances,to which great attention should be paid.