Stochastic dynamic analysis of the train-track-bridge system under tridirectional spatially correlated ground motions

Abstract

Due to seismic spatial variation and the correlation between tridirectional ground motions, the random vibrations of the train-track-bridge system are different from those under uniform seismic excitations. To study this difference, a high-speed train traversing a multi-span bridge under both track irregularities and tridirectional spatially correlated ground motions is investigated by using the pseudo-excitation method. Through calculating stochastic dynamic responses of the system, the influences of seismic spatial variation and the correlation between tridirectional ground motions are evaluated for the maximum standard deviations of bridge accelerations, train accelerations, the wheel-rail contact force, and the offload factor. The results show that these influences significantly affect the stochastic dynamic responses of the train-track-bridge system. Therefore, they cannot be ignored in the stochastic dynamic analysis of the train-track-bridge system under multi-support seismic excitations.