Influence of soil stiffness on building vibrations due to railway traffic in tunnels: Numerical study

In this paper a numerical study about the influence of soil stiffness on the assessment of vibrations induced by railway traffic in tunnels is presented. A comprehensive numerical model is used to achieve the lumped objective, where the source of vibration (train-track interaction), the propagation of vibrations (tunnel-ground system) and their reception (building close to the railway infrastructure) are simulated by a sub-structuring approach. It was found that soil stiffness plays a relevant role on the mechanisms of propagation of vibrations through the ground as well as on soil-structure interaction. Regarding the last topic, different approaches were made for the inclusion of the SSI effects, namely a detailed boundary elements formulation and a simplified lumped-parameter model. The performed study revealed that the usage of lumped parameter models can be seen as a good option considering the compromise between accuracy of the solution and reduction of the computation effort. (C) 2014 Elsevier Ltd. All rights reserved.