Investigating geogrid-reinforced ballast using laboratory pull-out tests and discrete element modelling

This paper presents an evaluation of the interlocking behaviour of geogrid-reinforced railway ballast. Experimental large box pullout tests were conducted to examine the interaction between ballast and the biaxial geogrid. The Discrete Element Method (DEM) has then been used to model the interaction between ballast and geogrid by simulating large box pullout tests and comparing with experimental results. The DEM simulation results have been shown to provide good predictions of the pull-out resistance and examine the effect of clump shape on the pull-out resistance and also the distribution of contact forces. Therefore, the calibrated geogrid model and clumps as ballast particles hold much promise for investigating the interaction between geogrids and ballast and therefore optimising performance.