A mixed space-time and wavenumber-frequency domain procedure for modelling ground vibration from surface railway tracks

Abstract

This paper presents a methodology for studying ground vibration in which the railway track is modelled in the space-time domain using the finite element method (FEM) and, for faster computation, discretisation of the ground using either FEM or the boundary element method (BEM) is avoided by modelling it in the wavenumber-frequency domain. The railway track is coupled to the ground through a series of rectangular strips located at the surface of the ground; their vertical interaction is described by a frequency-dependent dynamic stiffness matrix whose elements are represented by discrete lumped parameter models. The effectiveness of this approach is assessed firstly through frequency domain analysis using as excitation a stationary harmonic load applied on the rail. The interaction forces at the ballast/ground interface are calculated using the FE track through-ground coupling in the lumped parameter model, which has been found to be necessary for both track dynamics and ground vibration predictions.

Modelling, simulation and evaluation of ground vibration caused by rail vehicles

“…The forces acting on the ground beneath each sleeper were then transformed into the frequency domain and combined with analytical Green's functions for the soil to predict the response at locations away from the track. Koroma et al [140] extended this approach to include interactions between adjacent sleepers through the ground. The response of the ground was determined by transforming the forces beneath the sleepers into the wavenumber domain so they could be applied directly in a frequency-wavenumber analytical ground model.…”

Efficient time–frequency approach for prediction of subway train-induced tunnel and ground vibrations

“…Subsequently, the effect of through-ground coupling was further considered by Koroma et al. 35 Connolly et al. 36 proposed a 2.5 D time–frequency modelling methodology to simulate the generation of railway vibration caused by singular defects.…”

“…36 proposed a 2.5 D time–frequency modelling methodology to simulate the generation of railway vibration caused by singular defects. However, the above-mentioned studies 34–36 focused on the applicability of the time–frequency hybrid approach to the prediction of the vibration responses of the train–track–soil (–structure) system, and the computational efficiency of the time-domain solution has not been studied. The coefficient matrices of the moving mass problem are time-dependent as the position of the moving train changes with time.…”

Rigorous vehicle-soil-track simulation of high-speed rail through optimization-based model order reduction

“…An LP assembly considering both the direct and coupling behavior of the subsoil segment in a simplified manner has been recently proposed in [25] and used in [26] where the direct and coupling behaviors are roughly approximated by Kelvin-Voigt and enhanced Kelvin-Voigt models. Finally a sophisticated LP methodology for the simulation of the subsoil domain has been recently proposed in [27]. However, even the most sophisticated LP methods implemented in the simulation of soil-track-vehicle interaction introduce a number of limitations.…”