Numerical and laboratory investigation on lateral resistance of ballasted track with HA110 sleeper

Abstract

Lateral displacement of sleepers and uneven settlement in ballast layer induced by lateral loading of trains running through the curves, the continuous rail's thermal force, and the discontinuity of the ballast particles. One of the most critical challenges in railway track mechanics is lateral displacement of the sleeper affected by dimensions and geometric shape of the sleeper, ballast type, and density. Various procedures, such as using special sleepers (ladder, frictional, winged, etc.) instead of the ordinary type, have already been exercised to enhance track stability. In this study, lateral resistance of HA110 wide sleeper was investigated by single-tie push test (STPT) in a superstructure laboratory. Moreover, load imposed by the sleepers to ballast layer in the STPT and state of force distribution in ballast layer simulated using discrete element method (DEM).The laboratory and numerical investigation results indicate that lateral resistance is enhanced by 31% by increasing involvement of the number of ballast particles and reduced force applied to each ballast particle. Numerical and laboratory studies also indicate that the friction between the sleeper bottom and ballast particles plays the most significant role in providing lateral resistance. Moreover, studying the effect of vertical load on lateral resistance of HA110 and B70 sleepers through DEM simulation indicates that applying static vertical load of 5, 10 and 15 tonnes, the lateral resistance of HA110 sleeper would be3, 4.3, and 5.7%, respectively, higher than B70 type.