Experimental and numerical simulation of the mechanical characteristics of rocks containing hole and flaw after grouting

Uniaxial compression experiments and numerical simulation by RFPA 2D on model specimens containing a hole and a flaw with different flaw inclinations were conducted to investigate the influence of grouting body on the stress environment, failure mode and mechanical parameters of specimens. The specimens without and with grouting body were compared. The results of experimental and numerical simulations show that the grouting body reduces the stress concentration, the maximum compressive stress and tensile stress of specimens decrease, and their amplitude reductions are in the range of 7.6% to 9.8% and 0.4% to 9.8%, respectively. The failure modes, mechanical parameters and their variation amplitudes after filled are closely related to the inclination of the pre-existing flaw. A horizontal/vertical inclined flaw leads the specimens without and with grouting body to fail in a mode of cutting through the rock bridge. The peak and residual strength are the smallest and their amplifications are the highest in the case of an inclined flaw where the failure mode is controlled by the presence of such a flaw. Compared with the specimens without grouting body, the peak strength and residual stress of the physical and numerical model specimens with grouting body increase, and the peak strength amplifications are in the range of 5.45% to 23.33% and 4.18% to 14.29%, respectively, and the residual stress amplifications are in the range of 31.68% to 161.71% and 22.54% to 73.85%, respectively.