Author/Authors :
Cheng, Jingyi Key Laboratory of Deep Coal Resource Mining (CUMT) - Ministry of Education of China, School of Mines - China University of Mining and Technology, Xuzhou, Jiangsu, China , Zhang, Hongwei Key Laboratory of Deep Coal Resource Mining (CUMT) - Ministry of Education of China, School of Mines - China University of Mining and Technology, Xuzhou, Jiangsu, China , Wan, Zhijun Key Laboratory of Deep Coal Resource Mining (CUMT) - Ministry of Education of China, School of Mines - China University of Mining and Technology, Xuzhou, Jiangsu, China
Abstract :
The mechanical properties and permeability evolution of sand-infilled rock joints during the shear process is an important issue in rock engineering, such as it pertains to hydraulic fractures filled with proppant. Shear can disrupt the preexisting hydraulic and mechanical equilibrium conditions, thus affecting fluid flow. In this study, we simulate the shear behavior of rock joints with variable roughness and sand infilling thickness using the discrete element code PFC2D. Rock joint roughness is evaluated by the joint roughness coefficient (JRC), and sand infilling thickness is evaluated by a thickness ratio (i.e., ratio of infill thickness to rock height) ranging from 0.02 to 0.20. The results show that peak shear strength decreases with the thickness ratio in a relation that can be expressed by a hyperbolic function. We also measure the permeability evolution during shearing and find that the permeability of infilled rock joints increases with both the thickness ratio and JRC.
