Free field vibrations caused by high-speed lines: Measurement and time domain simulation

In recent years, the high-speed train (HST) network has developed considerably, unfortunately increasing vibration nuisances in its neighbourhood. This paper aims to present some vibration measurements collected on a Belgian site located between Brussels and Paris/London and travelled by the Thalys and Eurostar high-speed trains, and to compare them with the results obtained by a recently developed model, involving the compound vehicle/track/soil system. Assuming that the soil can be reasonably decoupled from the track, the approach first considers the train/track subsystem. The latter is studied by combining a multibody model of the vehicle with a finite element model of the track, both so far limited to the vertical motion. The ground forces given by this first simulation are then applied on a finite/infinite element model of the soil subsystem, where the infinite elements are placed on the border of the mesh in order to properly represent an unbounded domain. Both simulations are performed in the time domain, offering the opportunity to include non-linearities. The good correspondence between numerical and experimental results shows that the model is reliable for predicting the vibration produced by the high-speed vehicles. Finally, the paper presents some cases showing the importance of including the complete vehicle and the soil layering to the model.