Dynamic analyses of track and ground coupled system with high-speed train loads
列车荷载作用下轨道和地基的动响应分析

The wave propagation in track structure and nearby ground induced by the high-speed train operations have been studied herein. The interaction problem of train track and multi-layered ground has been solved by applying dynamic substructure method. The studied dynamics system comprises two substructures: one is the moving train and the track structure which is supported by sleepers; and the other is the layered visco-elastic ground which is subject to the discretely distributed loads from sleepers. Two components are coupled with the continuum condition at the contact interface. The track and nearby ground dynamic responses in frequency and wave-number domain have been obtained by solving the gqverning differential equations with the Fourier transform method. The time histories of responses also are available from the inverse Fourier transform. From the numerical study, the vibration intensities of track structure and nearby ground can be evaluated for the high-speed train operation. At the same time, an effective method has been proposed to estimate the critical speed of train running on track ground for possible resonance, which is of paramount importance to ensure the safety of high-speed train operations.