Abstract: In order to investigate the anchoring effects of the bolts on the jointed rock mass and its influences on crack propagation, the unanchored and anchored rock-like specimens with joint angles of 15o, 30o, 45o, 60o, 75o and 90o were made. The MTS816 was used for uniaxial compression test, and the acoustic emission (AE) and digital image correlation technology (DIC) were used to monitor the crack growth. In addition, the particle flow code software PFC3D was used to study effects of different anchoring angles on crack propagation. The results show that the peak strength, peak strain and cracking stress of the anchorage unit are improved compared with the unanchored specimens. The existence of bolt reduces the stress intensity factor during the crack initiation and propagation of the tensile wings, which can limit the initiation and propagation of tensile cracks effectively. Moreover, the occurrence of shear cracks can be inhibited. The process of the tensile crack propagation can be divided into initial stage and acceleration stage. The displacement of the characteristic points of the specimens with bolts is smaller than specimens without bolts. According to the PFC3D simulation results, the anchoring effect is the most obvious when the anchoring angle ? is 45o. With the increase of the anchoring angle ?, the development degree of the tensile wing crack first increases and then decreases. The failure mode of the prefabricated fracture specimen changes from shear failure to tensile-shear compound failure, and then to shear failure. The results can provide a reference value for analyzing the stability of rock engineering.

Key words: rock mechanics, rock-like specimens, anchoring effect, crack propagation, PFC3D