流冰撞击力作用下列车–简支梁桥耦合振动分析

建立撞击荷载作用下列车‐桥梁系统动力分析模型,将现场实测的流冰撞击力时程作为系统的撞击荷载。通过计算机仿真分析,对流冰撞击作用下高速铁路桥梁的动力响应及其对桥上列车运行安全的影响进行研究。采用自编程序模拟列车过桥的全过程,计算分析7 m×24 m简支箱梁桥在流冰撞击力作用下动力响应及桥上高速列车的动力响应。计算结果表明,在实测流冰撞击力作用下,桥梁横向加速度以及车辆脱轨系数和轮重减载率等行车安全指标在列车速度250 km/h以上时超过容许值,说明流冰撞击作用对车桥系统耦合振动响应具有较大的影响。

Coupled vibration analysis for train and simply-supported bridge system subjected to floating-ice collision

A coupled vibration analysis model was established for train-bridge system subjected to floating-ice collision load.The force originated from the floating-ice collision,whose time history was measured in site experiment was taken as the load applied on the bridge piers in transient style.The dynamic responses of railway bridges subjected to floating-ice collision and their influences on the running safety of high-speed trains were analyzed by numerical simulation.The time history of a train traveling on a seven——span simply-supported bridge with 24m box girders when the floating-ice strikes bridge piers was simulated and the dynamic responses of the bridge and train vehicles were investigated.The calculation results show that the lateral acceleration of the bridge and running safety indices such as the derailment factors and offload factors of train vehicles will exceed the corresponding allowances when the train speed is higher than 250 km/h,indicating that collision of floating-ice has obvious effect on coupled vibration responses of train-bridge system.