Investigation on ground vibration displacements induced by high-speed trains moving on elastic-plastic multi-layered ground by 2.5D FEM

Abstract

Considering the soil as nonlinear material, the ground vibration displacements caused by high-speed train (HST) moving on the elastic-plastic multi-layered ground are investigated using a 2.5-dimensional finite element model (2.5D FEM), in which the improved Mohr-Coulomb model and the post-Eulerian integration algorithm are also introduced. The accuracy of the established model is validated with published data. Results show that, under different train speeds, the ground vibrations at the track center for the multi-layered soil media are predominantly affected by the properties of the topsoil layer. The ground vibration displacements within 2 m from the track center are controlled by resonance conditions. The displacement attenuation curves fluctuate more in the soft layer than the hard one when the train speed reaches or exceeds the Rayleigh wave speed of all soil layers. Additionally, increasing the elastic modulus of topsoil can effectively reduce the ground vibration displacements in the range of 0.0 m–2.5 m from the track center, and the effects of buried depth for the soft soil layer being slight and thus ignorable.