Reconstruction of Shear Surface Based on Joint Roughness Coefficient and Its Relation to Rock Shear Strength

Abstract

Rock strength is a fundamental parameter in rock mechanics, serving as the basis for predicting rock behavior under different loading conditions. Among the various approaches to characterizing rock strength, shear testing of discontinuities plays a crucial role. The Joint Roughness Coefficient (JRC) provides an empirical link between joint surface roughness and shear strength parameters. In this study, joint surface profiles were reconstructed statistically based on JRC parameters and subsequently reproduced using three-dimensional (3D) printing technology. The printed molds were employed to cast laboratory specimens with pre-formed shear surfaces, which were then tested under direct shear conditions. The shear strength parameters obtained from the tests were analyzed in relation to their corresponding JRC values. The results demonstrate that the reconstructed and 3D-printed surfaces were successfully fabricated and accurately replicated joint roughness geometries. Direct shear tests confirmed the expected trend, with shear strength increasing alongside JRC. These findings indicate that shear surfaces can be prefabricated and manipulated with controlled roughness, providing a reliable and reproducible platform for investigating the mechanical behavior of rock joints.