Numerical Simulation of Rock Failure Process Using Improved Rigid Body Spring Method

Rock failure process is simulated using an improved rigid body spring model (RBSM). A procedure based on point saturation theory is proposed to generate uniformly distributed random Voronoi cell, which is employed as the basic mesh for the improved RBSM. The midpoint contact model of original RBSM is modified into distributed interface contact model. A simple failure criterion combining Mohr-Coulomb criterion with tension strength is employed to account for fracture evolution. It is found from a series of numerical tests that mesh size and mesh arrangement have little effects on the relationship between macro- and meso- elastic parameters. A fitting formula is developed for determination of relationship between macro and micro elastic parameters. Numerical studies against Vienne rock tests under various confining pressures show that a good agreement is obtained between experiments and numerical results from the proposed model.