Discrete Element Modeling Of Railroad Ballast Under Simulated Train Loading

Abstract

Ballasted tracks have been widely used in many countries around the world. Ballast layer is the main element in ballasted track. After service, ballast aggregates degrade and deform. Periodical maintenance for ballast layer is required; which is a cost and time expensive activity. Researchers used numerical approaches to understand the behavior of railroad ballast that leads to efficient design and maintenance. The Discrete Element Method (DEM) has been used increasingly to understand the mechanical behavior of railroad ballast, more frequently through box test. Most researches in the literature simulate the train loading as a pure continuous sinusoid based on train speed and axle spacing; unlike the actual loading induced by trains. This study aims to show the influence of simulated train loadings on ballast mechanical behavior using DEM via box test. The study utilizes the theory of Beam on Elastic Foundation to simulate a more realistic train load. The results from the more realistic simulated train load are compared with those from a sinusoidal load. The compared results highlight the influence of the simulated train load on the mechanical behavior of railroad ballast.