Three-dimensional modelling of train-track and sub-soil analysis for surface vibrations due to moving loads

Two mathematical models and numerical techniques for solving problems associated with the wave propagation in a track and an underlying soil due to passing trains are presented and compared. For the analysis, the thin layer method/flexible volume method (TLM/FVM) and the boundary element method (BEM) are employed to investigate the three-dimensional dynamic response of the free field nearby railway lines induced by the moving loads acting on the surface of a homogeneous or layered half-space. Particular interest is paid to influence of the mechanical properties of the railway track configuration on the vibrations covering surface propagation. A common feature of all simulation models is the application of the sub-structuring approach in the frequency domain. The results of the present numerical simulation are initially compared to an analytical and other numerical solutions. A comprehensive numerical investigations have been carried out to indicate the influence of different parameters on the amplitude reduction due to presence of an open trench. The results point out that using an open trench barrier with appropriate geometrical properties, a notable reduction level can be achieved.