Railway vibrations induced into the soil: experiments, modelling and isolation. - Vibrations induites dans les sols par le trafic ferroviaire : exp\'erimentations, mod\'elisations et isolation

TL;DR

This paper investigates railway-induced soil vibrations through experiments and modeling, aiming to understand their propagation and develop mitigation techniques to reduce environmental nuisances.

Contribution

It provides a comprehensive analysis combining in situ and laboratory experiments with theoretical and numerical models to study railway vibrations and their mitigation.

Findings

Soil vibrations vary significantly with soil properties and train parameters.

Modeling helps predict vibration propagation and attenuation in different configurations.

Mitigation techniques can effectively reduce vibration impacts on the environment.

Abstract

Railway traffic induces cyclic and dynamic loadings in the track structure but also in the close environment (Degrande et al. 2006, Fran\c{c}ois et al. 2007, Kausel 2008, Lefeuve-Mesgouez et al 2002, Paolucci et Spinelli 2006). The analysis of such excitations and their effects (e.g. vibrations, waves, etc) is fundamental to estimate their level and mitigate their potential consequences (settlements, nuisances, etc). After a brief summary of the current regulations, in situ experiments show the variability of the parameters characterizing the main phenomena (wave propagation into the soil, induced vibrations, etc). The main dynamic laboratory experiments are then discussed. They allow the estimation of the dynamic features of the materials (e.g. resonant column test), but also a simplified analysis of the main phenomena under controlled conditions (e.g. experiments in a geotechnical pit, centrifuge tests). The vibratory sources and the impedance ratios between the various soil layers (or some inclusions) being known, it is then possible to model some specific or actual configurations through theoretical (transfer functions) or numerical (e.g. finite elements, boundary elements) methods. Parametric studies allow the analysis of the propagation phenomena and the attenuation process in the soil in order to investigate the spatial variations of the vibrations amplitude in such various configurations. Finally, it may be useful to consider mitigation or isolation techniques in order to limit the consequences of the induced vibrations (e.g. vibratory nuisances, radiated noise). Several experimental and numerical results illustrate this key issue.