横向撞击力对铁路桥梁及行车影响的模型实验研究

高速铁路高架桥梁很多，跨越公路的桥墩被汽车撞击所引起的振动会影响列车运行安全。本文利用车—轨—桥耦合动力试验平台，通过模型试验研究了横向撞击力对桥梁及桥上车辆运行安全的影响规律。试验过程中采集了撞击处撞击力时程、桥墩底部动应变、墩顶动位移、墩顶加速度时程，梁1/4，1/2，3/4处的横向动位移和加速度时程，以及车辆的三向车体加速度时程，计算得到桥墩自振频率等振动特性。分析了车桥系统有无撞击力作用时的动力响应，以及撞击力对桥梁及桥上运行车辆的影响规律。结果表明，横向撞击使桥梁的动力响应大幅度增加，并对车辆运行安全有很大的影响。最后根据撞击力时程探讨了瞬态撞击力的等效静力计算方法并验证，为工程设计提供参考。

Model test study on effect of lateral collision force on railway bridge and vehicle running safety

As the number of elevated bridge of high-speed railway grows, the possibility of the bad effect on the running safety of trains caused by the collision between motors and bridge piers also increases. A model test based on the equipment of vehicle-track-bridge coupling system is carried to analyze the variation of bridge and vehicle’s running safety under lateral collision force. The collision force's time history, dynamic strain on the bottom of pier, dynamic displacement and acceleration time history on the top of pier, the dynamic displacement at 1/4, 1/2 and 3/4 span of the bridge beam, and the tri-direction acceleration time histories of the vehicle are obtained. The vibration characteristics such as pier natural frequencies are also calculated. The results show that the lateral collision greatly increases the dynamic responses of the bridge, which may dramatically affect the running safety of vehicles. According to the collision time history, the methods of calculating equivalent static forces are discussed and verified in this field, which may provide a reference for engineering design.