Simulation Study on the Size Effect of Secant Modulus of Rocks Containing Rough Joints

The secant modulus reflects the ability of rocks to resist deformation, and it is mostly used to evaluate rock strength and deformation evolution. Due to the existence of rough joints in rocks, the secant modulus changes according to rock size. Therefore, it is very important to effectively obtain the secant modulus to evaluate rough-jointed rock deformation. In this paper, the regression analysis method is used, and 25 sets of simulation models are set up to discuss the influence of joint roughness and rock size on the rock secant modulus. The research shows that the secant modulus increases exponentially with the increase in rock size, and it increases as a power function with the increase in joint roughness. The characteristic size of the secant modulus increases exponentially with the increase in joint roughness, also as a power function. This paper gives the specific forms of these four relationships. The establishment of these relationships enables the prediction and calculation of the secant modulus and provides guidance for rock deformation analysis.