Analysis of ground vibration induced by trains on saturated layered ground

The thin layered method (TLM) is adopted to derive the solution of Lamb's problem for layered saturated foundation under the action of dynamic loads. The displacement expression in the frequency-wave number domain for layered saturated medium is obtained by discreting Biot's axisymmetric dynamic equation in vertical coordinates, and by the Fourier series decomposition in tangential coordinates and Hankel transform in axial coordinates. Then the inversion of Hankel transform and Fourier synthesis are used to get the displacement expression in the frequency domain. Combined a moving train-track-ground interaction model, a parametric study is given to evaluate the ground vibration induced by train moving loads on the saturated layered ground. The effect of the soil parameters, such as permeability coefficient, porosity, fluid viscosity coefficient and shear wave velocity, on the attenuation of ground vibration is investigated and discussed in detail. The results show that the parameters of the first layer affect ground vibration induced by train more significantly than those of the second layer. It is also found that the permeability coefficient of soil, the fluid viscosity coefficient, porosity and shear wave velocity have great influence on the ground vibration.