Response of railway track system on poroelastic half-space soil medium subjected to a moving train load

Abstract

a b s t r a c tBased on the dynamic poroelastic theory of Biot, dynamic responses of a track system and poroelastic half-space soil medium subjected to moving train passages are investigated by the substructure method. The whole system is divided into two separately formulated substructures, the track and the ground, and the rail is described by introducing the Green function for an infinitely long Euler beam subjected to the action of moving axle loads of the train and the reactions of the sleeper. Sleepers are represented by a continuous mass and the effect of the ballast is considered by introducing the Cosserat model for granular medium. Using the double Fourier transform, the governing equations of motion are then solved analytically in the frequency-wave-number domain. The time domain responses are evaluated by the inverse Fourier transform computation for a certain train speed. Computed results show that the shape of the rail displacements of the elastic and poroelastic soil medium are in good agreement with each other of the low train velocity, but the result of the poroelastic soil medium is significantly different to that of the elastic soil medium for the high train velocity which is higher than Rayleigh-wave speed in the soil. The influence of the soil intrinsic permeability on soil responses is discussed with great care in both time domain and frequency domain. The dynamic responses of the soil medium are considerably affected by the fluid phase as well as the load velocity.

Three‐dimensional dynamic response of ground with a poroviscoelastic interlayer to a harmonic moving rectangular load

“…, Cai et al . and Lefeuve‐Mesgouez and Mesgouez investigated the dynamic response of a saturated half‐space. Xu et al .…”

Dominant frequencies of train-induced vibrations in a seasonally frozen region

“…Some studies were proposed to investigate the ground vibrations through establishing a track system-saturated model (Cai et al, 2008;Cai et al, 2010;Cao et al, 2011). It was found that when the train speed approaches the Rayleigh wave speed of the ground, the single-phase elastic soil model would underestimate the ground vibrations significantly, and the poroelastic soil model was essential for the prediction of train-induced ground vibrations.…”

Dynamic analysis of a high-speed train operating on a curved track with failed fasteners

“…Among the existing dynamic models of railway vehicle coupled with a track, most were used to deal with vehicle/track vertical interaction problems in relatively low frequency ranges (Nielsen and Igeland, 1995;Ripke and Knothe, 1995;Frohling, 1998;Oscarsson and Dahlberg, 1998;Sun and Dhanasekar, 2002;Lei and Mao, 2004;Cai et al, 2008), and a few were used to analyze the lateral and vertical dynamics (Zhai et al, 1996;Jin et al, 2006;Xu and Ding, 2006;Baeza and Ouyang, 2011;Xiao et al, 2011). Although the coupled vehicle/track models can solve many scientific problems effectively, there are some issues that these models cannot deal with.…”