Three-dimensional dynamic analyses of track-embankment-ground system subjected to high speed train loads.

Qiang Fu,Changjie Zheng

doi:10.1155/2014/924592

Abstract

A three-dimensional finite element model was developed to investigate dynamic response of track-embankment-ground system subjected to moving loads caused by high speed trains. The track-embankment-ground systems such as the sleepers, the ballast, the embankment, and the ground are represented by 8-noded solid elements. The infinite elements are used to represent the infinite boundary condition to absorb vibration waves induced by the passing of train load at the boundary. The loads were applied on the rails directly to simulate the real moving loads of trains. The effects of train speed on dynamic response of the system are considered. The effect of material parameters, especially the modulus changes of ballast and embankment, is taken into account to demonstrate the effectiveness of strengthening the ballast, embankment, and ground for mitigating system vibration in detail. The numerical results show that the model is reliable for predicting the amplitude of vibrations produced in the track-embankment-ground system by high-speed trains. Stiffening of fill under the embankment can reduce the vibration level, on the other hand, it can be realized by installing a concrete slab under the embankment. The influence of axle load on the vibration of the system is obviously lower than that of train speed.

Highlights

With the rapid development of high speed railway in China, the issue on dynamic response of soil and environment vibration induced by the moving trains has been paid more attention, and the researchers have paid attention to the dynamic effects associated with train-track interaction [1,2,3,4,5,6,7,8]
The soil vibration problem was first studied by Lamb in 1904, whose pioneering research mainly focused on the dynamic response of elastic half-space and elastic body with infinite boundary generated by stationary loads or approximately stationary loads [9]
Sheng et al [19] studied the ground vibration generated by a harmonic load that moves along a railway track

Summary

Introduction

With the rapid development of high speed railway in China, the issue on dynamic response of soil and environment vibration induced by the moving trains has been paid more attention, and the researchers have paid attention to the dynamic effects associated with train-track interaction [1,2,3,4,5,6,7,8]. In [25, 26], an analytical approach was used to investigate dynamic responses of a track system and the poroelastic half-space soil medium subjected to a moving point load under three-dimensional condition. In [33], a general and fully three-dimensional multibody finite element boundary element model, formulated in the time domain to predict vibrations due to train passage at the vehicle, the track, and the free field, is presented. Hall [34] and Ju et al [35] used the finite element method to perform three-dimensional time domain simulation for train-induced vibrations of embankment on layered ground. The dynamic three-dimensional (3D) finite element program ABAQUS was chosen for creating the models used to simulate the vibration of track-embankmentground system induced by high speed train moving on the track system. The ground vibration characteristics of track-ballast-embankment-ground system are analyzed under different train moving speeds

Numerical Model of Track-EmbankmentGround System

Dynamic Responses of Track-EmbankmentGround System

Parametric Study

Findings

Conclusions