STUDY OF STRESS-PATH-DEPENDENT BEHAVIOR OF ROCKFILLS USING DISCRETE ELEMENT METHOD

Rockfills have been widely used in high-fill projects. The study of the mechanical properties of rockfills usually requires large-scale test equipment because of large particle size. This paper explores to study the stress-path-dependent behavior of rockfills using a Discrete-Element numerical-simulation Method (DEM). A number of spherical units can be bonded into a cluster in DEM to simulate a crushable rockfills particle. This paper briefly introduces the calculation principles and characteristics of the discrete element method as well as its simulation process, and builds up a discrete model of rockfills specimen. Model parameters were determined and the model was calibrated according to a set of large scale conventional triaxial tests of rockfills under different confining pressures. Using the model with same parameters, the stress-strain relationship and volumetric strain characteristics of rockfills along different stress loading paths were predicted. By contrasting the simulation results with the large scale stress-path triaxial testing data, the discrete element model was verified to simulate the mechanical properties of rockfills under different loading paths accurately, meanwhile the small strain stiffness characteristics of rockfills was discussed.