Semi-analytical approach for analyzing soil vibrations caused by moving trains

A semi-analytical approach is presented for the analysis of three-dimensional ground vibrations induced by trains traveling over a multi-span elevated bridge with pile foundations. The train is modeled as two sets of moving loads, with one accounting for the front wheelsets and the other for the rear wheelsets, the bridge as a series of elastically supported beams, and the ground as a viscoelastic half space. By the present semi-analytical technique, the entire vibration problem is divided into three subproblems, each dealing with the dynamic behavior of the superstructure of the bridge, the interaction between the bridge foundations and surrounding soils, and the wave propagation through the half space by point sources. The proposed approach is verified by comparing the results of analysis of an example problem with that by the finite element method.