Study on the Degradation Law of Artificial Joint Surfaces with Natural Morphologies under Quasi-Static Cyclic Shearing

Abstract

In this paper, a series of quasi-static cyclic shear tests were performed on artificial rock joint specimens with natural morphologies at different normal stress levels. After shearing, combined with 3D scanning technology and image processing, the 3D morphology parameter, A0θmax∗/(C+1), of 36 analyzed directions was measured to investigate the damage and degradation laws of the joint surfaces. The polar curves of the roughness parameter shrank from a circular to an elliptical shape, with the shear direction as the minor axis. The roughness degradation rates and the shear cycles were mutually interrelated with the normal stress levels, which had a tendency to be fast initially and then to slow down under higher normal stress. Influenced by the cyclic shear direction, the 3D roughness of the joint surfaces degenerated anisotropically and sustained the most serious damage along the shear direction. Two damage and degradation fitting formulas were proposed, which could aid the assessment of residual roughness under different stress histories and the cumulative wear degree.