Experimental and numerical study of crack propagation characteristics of tri-cracked rocks based on distinct element method

In order to study the static damage characteristics of the tri-cracked rock, the distinct element numerical simulation software PFC^2D and model tests were used to analyze the peak strength, stress-strain curve and crack propagation characteristics of the tri-cracked rock, and to verify the feasibility of the distinct element numerical simulation method. By varying the horizontal confining pressure and crack length of rock, the mechanical response mechanism of the tri-cracked rock under uniaxial compressive loading was analyzed. The results show that the intermediate transverse crack has a greater effect on the peak stress of the cracked rock, and the intermediate vertical crack has a less effect on the peak stress of the cracked rock. During the loading process, stress concentration occurs at the crack tip primarily and ultimately two main cracks of about 70° are formed through three prefabricated cracks. With the increase of confining pressure, the peak stress of the tri-cracked rock increases first and then decreases.