P. Alves Costa

VIBRATIONS IN BUILDINGS DUE TO RAILWAY TRAFFIC IN TUNNELS: MODELLING STRATEGIES AND INFLUENCE OF SOIL STIFFNESS

Abstract. In this paper a numerical study about the influence of soil stiffness on the assessment of vibrations induced by railway traffic in tunnels is performed. A comprehensive numerical model is used to achieve the lumped objective, where the source of vibration (traintrack 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 the soil stiffness plays a relevant role on the mechanisms of propagation of vibrations through the ground as well as on the soil-structure interaction. Regarding the last topic, different approaches were attended for the inclusion of the SSI effects, namely a detailed boundary elements formulation and a simplified lumped-parameter model. The study performed revealed that the usage of lumped parameter models can be faced as a good option taking into account the compromise between accuracy of the solution and reduction of the computation effort.