Research on Peak Shear Strength Criterion of Rock Joints Based on the Evolution of Dilation Angle

The surface morphology of joints directly determines the contact area and peak shear strength rock in shearing. This research gives a detailed description three-dimensional roughness parameters proposed by Grasselli, discusses characteristics parameter C different ranges. Quoting Xia's direct test data, relationship strength, strength/normal stress, residual dilation with normal stress are studied. deficiencies previous classical criteria explained detail. A new criterion is established based on boundary conditions angle. nonlinear characteristic included angel, so that satisfies Mohr–Coulomb law form. In expression initial angle, fact decreases after once sheared. Finally, data Grasselli Yang used to compare prediction accuracy Grasselli’s criterion, Yang’s Xia’s criterion. general, has highest degree agreement results.