Simulation and mitigation analysis of ground vibrations induced by high-speed train with three dimensional FEM

Abstract

The high speed railway, which acts as a safer and faster means of transportation, has grown rapidly around the world, especially in China. Meanwhile, the vibration induced by high-speed train (HST) arouses increasing concerns and cannot be ignored. This paper describes ground vibrations with three dimensional models formulated in the time domain using the finite element method (FEM). Absorbing boundaries and Rayleigh damping approach are used to prevent wave reflections from the artificial edges and to simulate the material damping, respectively. Investigations of ground vibration caused by unit load under different speeds and frequencies are given. An inclined classification of ground vibration and the sensitive frequency ranges of surface ground are then found. Moreover, the effects of subgrade treatment and sub-soil treatment on vibration isolation are discussed. It concludes that due to the attenuation effects of subgrade structures on high frequency range, noticeable reductions can be obtained in surface ground vibration. And when a high subgrade or a composite one is applied, the effects are better. The depth of sub-soil treatment would have more positive influence on ground vibration isolation and costs relatively less, compared with its replacement ratio and width. Negative influence may even occur when the sub-soil treatment width becomes larger. Additionally, some useful recommendations are proposed in this paper.