Running safety of high-speed train on rigid frame bridge subjected to earthquakes

To research the running safety when high-speed train running over a high-pier rigid frame bridge subjected to earthquakes, a coupling vibration model is set up based on the train-track-bridge dynamic interaction theory. In this model, the seismic action is solved by the relative motion method and the ballast track is simulated by the elastic point support model with three layers. As an example, a high-pier rigid frame bridge with spans of (88+168+88) m is modelled, and the dynamic responses of vehicle and bridge system under El Centro seismic wave are calculated. The analysis results show that the dynamic responses of the high-pier rigid frame bridge present weakly coupled in plane and out plane, moreover the running safety of the train is decreased along with the increase of seismic amplitude and train speed. In addition, the most threat direction to the running safety of the train on bridge is transverse, and the running safety threshold of ICE3 subjected to 7 degree, 8 degree and 9 degree frequent seismic is 275, 250 and 225 km/h.