Effect of joint roughness coefficient and size on shear and characteristic strengths of structural planes

Joint roughness coefficients (JRCs) influence the shear and characteristic strengths of structural planes; however, the relationship model of this influence is yet to be derived. This study investigates 11 numerical simulation programs using a realistic failure process analysis software. The influence of size and JRC on the shear strengths of the structural planes was studied. The stress-strain curves of different JRCs and their sizes were analyzed. Mathematical models of the shear strength of structural planes and JRC and sizes were formulated and proposed, and their expressions were obtained. Moreover, mathematical models of JRC and the characteristic size and strength of the structural planes were established.