Numerical analysis of the effect of a fault on blast-induced wave propagation

Rock masses consist of intact rock and discontinuities such as faults, joints and bedding planes. The presence of such discontinuities in rock masses dominates the response of jointed rock masses to static and dynamic loading. This paper focuses on the propagation and dynamic effects of blast waves in faulted rock masses. In order to investigate the effect of faults, a numerical simulation was conducted. The 2D distinct element code (UDEC) was used to model fault effect on rock failure and stress distribution through the rock mass due to blast wave propagation. The blast loading history was simplified and applied to the blasthole walls. Accordingly, the interaction of explosive energy transferred to the rock mass from the blasthole pressure was examined as a function of distance to the fault plane from the blasthole. A Mohr-Coulomb material model was used for host rock to allow for plastic failure calculations. The conducted numerical study describes the role of fault in blasting in a qualitative manner. On the other hand, a free face boundary was considered as a common blast operation which is conducted in surface mining.