Comparison of Joint Models Used for the Propagation of Shear Waves Across Jointed Rocks

Shear waves are generated in jointed rocks due to various sources such as earthquakes, mining, blasting. Strains of varying levels get developed in the rocks, due to seismic wave propagation, depending on the medium of propagation and distance between vibration source and area of interest. 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 three-dimensional distinct element code (3DEC). To represent the material behavior of discontinuities, two models, i.e., Coulomb slip (CS) joint model and continuously yielding (CY) joint model have been used. Coulomb slip model assigns elastic stiffness, frictional, cohesive and tensile strengths to joint, whereas continuously yielding joint model simulates continuous weakening behavior due to accumulation of plastic shear displacement. The test facility consists of friction bar, incident and transmitted plates. The friction bar generates shear wave in the incident plate due to its sliding movement. The validation of these numerical simulations has been done by comparing the peak particle velocities and peak particle displacements developed at the monitoring locations of incident and transmitted plates in the laboratory and in the numerical model. Parametric studies on the shear wave propagation have been conducted by varying the joint properties, in situ normal stress, applied load magnitude, and the results are presented in this paper.