GROUND VIBRATION INDUCED BY HIGH-SPEED TRAINS MOVING OVER VIADUCTS

摘要

This paper presents a semi-analytic approach for investigating the 3D vibrations of alongside ground surface caused by high-speed trains moving over viaducts. In this study, the train is modeled as two sets of moving loads, with one set for the front bogies and the other for the rear ones, the viaduct as a series of elastically supported beams, and the ground as a viscoelastic half-space. The semi-analytic approach presented herein consists of three key steps: (1) the analytic solution for the vibration of an elastically supported beam under a series of moving loads, (2) the simulation of the foundation-soil interaction by an equivalent lumped-parameter model, and (3) the adoption of Green's function for an elastic half-space under a point load. Such an approach allows us to consider the dynamic properties of the viaduct, the foundation-soil interaction, and the wave propagation property in the half space. The major characteristics of the train-induced ground vibration can be analyzed from its vertical and horizontal responses, through the 1/3 octave band and time history responses. Finally, a parametric study on the maximum vibration response of the ground was carried out, from which the key parameters involved can be identified.