Numerical Simulation of Shear Wave Propagation Through Jointed Rocks

Abstract

Shear wave propagation through jointed rock mass is a complex phenomenon as the waves get transmitted and reflected at the joints. The seismic wave propagation results in the development of strains of varying levels, depending on the distance of the source of the vibration from the point of interest and the properties of the material through which it propagates. This paper describes the numerical simulation of a test facility that generates shear waves in rock plates. The numerical simulations have been developed with the help of a distinct element code program, three-dimensional distinct element code (3DEC). The test facility has an incident and transmitted plates along with a friction bar that produces shear waves in the incident plate, which are transmitted across the joint to reach the transmitted plate. The numerical simulation is validated by comparing the maximum particle velocities and maximum particle displacements developed in the incident and transmitted plates due to the propagation of waves, in the laboratory and in the numerical model. The wave energy that is transmitted and reflected at the rock joints has been calculated from the particle velocities obtained at the monitoring points. The ratio of the shear stresses due to the wave propagation at the monitoring points and the wave velocity reduction across the joint also have been calculated. A parametric study on the shear wave propagation has been conducted by varying the normal stress, properties of the joint and the magnitude of the load applied and the results are presented in this paper.