Influence of ballast bulk density and loading conditions on lateral resistance of concrete sleeper components

From the perspective of the ballast railway track lateral stability, the sleeper-to-ballast interface has a vital role in the interaction between the sleeper and shoulder, crib, and base of the ballast layer. In this paper, ballast bulk density, vertical loading exerted by trains, and type of loading were considered as influencing factors on the variation of ballast components' contribution to the lateral resistance using the Discrete Element Method (DEM). For static tests, four vertical loadings of 0, 50, 100, and 150 kN, as well as three bulk densities of 1400, 1500, and 1600 kg/m3 of ballast, were prepared. For cyclic tests, four loading frequencies of 5, 10, 20, and 30 Hz were considered for a panel with a constant bulk density of 1500 kg/m³ subjected to 100 kN vertical loading. Simulations demonstrate that the lateral sleeper resistance is maximum when the ballast bulk density is approximately 1500 kg/m³.