Study of Effect of Ballast Particles on Lateral Resistance of Railway Track Using Discrete Element Method

Regarding to increasing demand for axle-load and fleet operation speed in the ballasted railway lines, provision of lateral-resistance is raised among the owners of railway industries. So, different solutions are presented to increase lateral resistance of the track in technical literature. Several factors affect the track lateral resistance but the most important one is the interaction between ballast layer and sleeper. Literature review shows that the interaction between ballast particles and sleepers has not widely been definitely studied by consideration of particle behavior of ballast material in lateral resistance problem. Therefore in this paper a numerical model has been developed to simulate single sleeper push test by discrete element numerical software PFC 2D. The results was compared with laboratory measurement results. Ballast grading used in this paper was according to the Group 2 of Iran Code No. 301 and the modeled sleeper was B70 concrete sleeper. To perform geometric modeling of the particles, clustering method was used as well as photography. Finally, regarding the results of the valid numerical model, sensitivity analysis were performed on the parameters affecting the lateral resistance including initial upright load, ballast material properties, ballast layer thickness and ballast shoulder width.