Dynamic analysis of a coupled high-speed train and bridge system subjected to collision load

A dynamic analysis model is established for a coupled high-speed train and bridge system subjected to collision-load. A 7×32 m simply-supported high-speed railway bridge with box girders is considered as an illustrating case study. A high-speed China-Star train is traveling on the bridge. The time history curve of a drifting-floe collision force is obtained from a field experiment and introduced as the excitation load on the bridge piers. Then, the dynamic response of the coupled train–bridge system subjected to the measured drifting-floe collision is calculated. Afterwards, the running safety indices such as derailment factor, offload factor and lateral wheel-rail force of train vehicles are investigated. The results show that the dynamic response of the bridge subjected to a collision load is much greater than the one without a collision, resulting in a big influence on the running safety of high-speed trains. For the case study, a critical train speed curve is proposed to evaluate the running safety of train vehicles on the bridge under drifting-floe collision with various intensities.