Modelling of ballast–geogrid interaction using the discrete-element method

Abstract

ABSTRACT: The interaction between geogrid and ballast is investigated using the discrete-element method (DEM). The DEM used can take into account the real shape of ballast stones. The paper shows that it is possible to reproduce the mechanical behaviour of real geogrids by bonding an array of spheres with bonds that can transmit forces and moments. Pullout test simulations using both spheres and realistic shapes (‘clumps') for the ballast material are used to determine the influence of the shape of ballast stones on the ballast–geogrid interlock. The paper shows that better interlocking between geogrid and ballast is achieved with realistic particles and highlights the importance of modelling accurately the shape of the particles.