Dynamic Response of Railway Vehicles Running on Long-Span Cable-Stayed Bridge Under Uniform Seismic Excitations

In order to evaluate the dynamic response of the train running on long-span cable-stayed bridges under uniform seismic excitations, a time-domain framework of analysis for the train-bridge system is established. The rail irregularities are treated as internal excitation and seismic loads as external excitation considering the inertia forces induced by the 3D seismic waves. The vehicles are modeled as mass-spring-damper systems, and the cable-stayed railway bridge is simulated by finite elements. A comprehensive analysis of the train-bridge system subjected to earthquake is conducted, focused on the effect of seismic ground motions on the dynamic response of the running train. Four kinds of seismic waves, each with three components, are simulated, with their spectral characteristics taken into account. To consider the stochastic characteristic of actual seismic waves, the effect of the incident angle and occurrence time of earthquakes on the bridge and vehicles is analyzed. Moreover, the earthquakes with various occurrence probability levels are also studied and the safety of the train running under the seismic action is evaluated, which may be used as the operation reference for the railway authority. The results demonstrate that the seismic ground motions have significant effects on the dynamic response of railway vehicles running on the long-span cable-stayed bridge under various spectrum characteristics, incident angles, occurrence times, and occurrence probabilities.