Experimental and Numerical Simulation Study on the Shear Behavior of Rock-like Specimens with Non-Persistent Joints  
[PERSON]  
1 Shandong Provincial Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao 266590, China; [EMAIL_ADDRESS] (G.W. ); [EMAIL_ADDRESS] (Z.L.) [PERSON]  
1 Shandong Provincial Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao 266590, China; [EMAIL_ADDRESS] (G.W. ); [EMAIL_ADDRESS] (Z.L.) [PERSON]  
1 Shandong Provincial Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao 266590, China; [EMAIL_ADDRESS] (G.W. ); [EMAIL_ADDRESS] (Z.L.) Footnote 1: email: {1,3}  
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on shear strength. [PERSON] et al. [10] conducted orthogonal tests focusing on joint roughness, rock bridge angle, rock bridge length, and normal stress, and evaluated the effect of these four variables on peak shear strength in direct shear tests, concluding that normal stress had the most significant effect. [PERSON] et al. [11] employed gypsum to shape the specimens and examined the effects of different normal stresses, rock bridge ratios, and the number of rock bridges on the failure process and shear strength. The research indicated that an elevation in normal stress would result in a transition of the specimen's failure mode from tensile failure to shear failure. [PERSON] et al. [12] prepared rock-like specimens and direct shear tests showed that joint roughness, shear rate, and normal stress had a positive correlation with peak shear strength and damage rate. In contrast to indoor tests, numerical simulation technology is a significant method for investigating the shear behavior of non-persistent joints due to its cost-effectiveness and operational simplicity. [PERSON] et al. [13; 14] conducted a numerical simulation study using PFC and summarized the effects of joint spacing, normal stress, rock bridge number, joint overlap, and rock bridge ratio on shear strength and failure patterns. [PERSON] et al. [15] analyzed the shear failure process under a Taguchi design with different joint lengths, angles, and numbers by combining indoor experiments and discrete element numerical simulations. The numerical results showed that cracks first appear at rock bridges and that crack propagation is influenced by joint geometry. [PERSON] et al. [16] employed PFC to summarize the peak intensity laws at various joint positions, concluding that the joint ends are critical areas for reinforcing non-persistent jointed rock masses. A lot of achievements have been made in the above research on the shear behavior of non-persistent joints, which greatly promoted the development of geotechnical engineering. However, there are still some research deficiencies. Firstly, exploration of the shear behavior of non-persistent joints based on parameters such as joint length, joint dip angle, joint spacing, rock bridge angle, and joint roughness has achieved initial results, but less research has been undertaken on joint aperture. As an important parameter for the evaluation of joints, joint aperture significantly influences the mechanical properties of the rock [17; 18]. Experimental results have shown that the joint aperture has a great effect on the permeability [19; 20] and compressive strength [21; 22] of the rock, while its effect on the shear behavior is not yet fully understood and needs to be investigated. In addition, the discrete element method (DEM), which treats the rock mass as a discontinuum [23], is currently a common analysis method among numerical simulation methods for non-persistent joints. The DEM can describe the interactions between particles in detail and has achieved outstanding results in the field of non-persistent joints.