Abstract
In order to express the mechanical behavior of soft rocks as faithful as possible by Discrete Element Method (DEM), it is important how to determine the parameters. In this study, we proposed a method to determine the stiffness of the sphere element and the parallel-bond from the elastic wave velocities and the parallel-bond strength from the unconfined compression strength (UCS). The specimen used in the experimental tests was the Toyoura sand bonded by a liquid grout in order to simulate a soft rock. The primary and shear wave velocities of the Toyoura sand and the bonded Toyoura sand specimens were measured by the bender element test and then the stiffness of the sphere element and the parallel-bond were calculated by those velocities. The unconfined compression test (UCT) by DEM based on those stiffness could cleverly express the secant Young’s modulus of the stress-strain relationship in the experimental UCT. In addition, the UCS provided the parallel-bond strength. Therefore, the main parameters for DEM can be obtained experimentally.
