Abstract：This paper presents a coupled discrete-finite element method for the interaction between geogrid and ballast particles. The clumps are employed to simulate the shape of ballast particles, the beam elements are used to compute the response of geogrid, a method for the transmission of dynamic parameters is proposed on the contact surface between discrete and finite element area. The reinforcement of geogrid on ballast particles is analyzed under cyclic loading. A further study on the mechanism of geogrid reinforcement is carried out by direct shear test of reinforced ballast particles. The results indicate that the lateral and vertical displacements decline obviously by the reinforcement of geogrid, the cohesive force and frictional angle of ballast material both enhance after reinforced by geogrid. Geogrid could increase the interlock of ballast particles, enhance the strength of ballast material and prevent the shear band cutting through from upper box to nether box.
2016, Vol. 37 
