Modelling of Railway Sleeper Settlement under Cyclic Loading Using a Hysteretic Ballast Contact Model

Elahe Talebiahooie,Matti Rantatalo,Jingjing Meng,Hans Mattsson,Florian Thiery,Erling Nordlund

doi:10.3390/su132112247

Elahe Talebiahooie, Matti Rantatalo + Show 4 more

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https://doi.org/10.3390/su132112247

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Journal: Sustainability	Publication Date: Nov 6, 2021
Citations: 2	License type: CC BY 4.0

Affiliation: Luleå University of Technology

Abstract

Ballasted tracks are common in the railway system as a means of providing the necessary support for the sleepers and the rails. To keep them operational, tamping and other maintenance actions are performed based on track geometry measurements. Ballast particle rearrangement, which is caused by train load, is one of the most important factors leading to track degradation. As a result, when planning maintenance, it is vital to predict the behaviour of the ballast under cyclic loading. Since ballast is a granular matter with a nonlinear and discontinuous mechanical behaviour, the discrete element method (DEM) was used in this paper to model the ballast particle rearrangement under cyclic loading. We studied the performance of linear and nonlinear models in simulating the settlement of the sleeper, the lateral deformation of the ballast shoulder and the porosity changes under the sleeper. The models were evaluated based on their ability to mimic the ballast degradation pattern in vertical and lateral direction. The linear contact model and the hysteretic contact model were used in the simulations, and the effect of the friction coefficient and different damping models on the simulations was assessed. An outcome of this study was that a nonlinear model was proposed in which both the linear and the hysteretic contact models are combined. The simulation of the sleeper settlement and the changes in the porosity under the sleeper improved in the proposed nonlinear model, while the computation time required for the proposed model decreased compared to that required for the linear model.

Highlights

Ballasted track is composed of two main parts called the superstructure and the substructure
Based on the contact models described above, one linear and one nonlinear model were generated in the present study
The linear contact model was used for all the implemented contacts, while in the nonlinear model, both the hysteretic and the linear contact models were used

Summary

Introduction

Ballasted track is composed of two main parts called the superstructure and the substructure. Ballast needs frequent maintenance actions such as tamping to retain or restore the track quality and ride comfort, as well as decreasing the probability of catastrophic incidents such as derailment. High track irregularities as the result of insufficient maintenance affect the passenger comfort [3] and deteriorate the vehicle–infrastructure interaction performance [4]. Maintenance planning, simulation of the track–train interaction and derailment risk assessment can be improved by acquiring accurate models of the ballast

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