Vibration Isolation of In-filled Trench in Layered Ground Under High-Speed Train Load with Track Irregularity

Abstract

A 2.5D train-track-ground FEM model is developed to analyze the vibration mitigation effectiveness of in-filled trench in layered ground under high-speed train loadings. The train load including the track irregularity is deduced by simplifying the track as an Euler-Bernoulli beam resting on a visco-elastic layered sub-grade. By simulating the in-filled trench as a heteroplasmon in a half-space, the 2.5D finite element formulas are derived by employing the fast Fourier transform. The vibration isolation effectiveness of in-filled trench on ground under train dynamic load at different speeds is analyzed. Then the effects of the width and depth of the in-filled trench are analyzed in detail. The results show that the vibration isolation effect of in-filled trench is better for moving trains at high speed than that at normal speed. In addition, increasing the depth and width of the in-filled trench improves the vibration isolation effectiveness under moving train load.