Anisotropic research on shear strength parameters of discontinuity based on three-dimensional laser scanning technology

Joint roughness coefficient(JRC) is one of the key factors affecting the discontinuity shear strength. The research on the discontinuity roughness and shear strength anisotropy is of great significance to engineering rock mass deformation and stability analysis. Currently,there are few papers reported on the discontinuity fractal dimension and its shear strength anisotropic analysis based on three-dimensional(3D) laser scanning technology. Taking a dam site in Guizhou Province for example,discontinuity surface morphology data obtained through 3D laser scanning are used to establish a digital elevation model to evaluate shear strength anisotropic of dolomite joint. On the basis of the variation function method,the anisotropy of discontinuity fractal dimension is studied and corresponding functional relationship between JRC and fractal dimension(D) is established. According to Barton standard contour curve and the actual stress state of dolomite,anisotropies of shear strength parameters based on the Barton equation are examined. The results show that cohesion and fiction angle change within the range of 0.20 to 0.75 MPa and 9.09° to 36.87°,respectively. The anisotropies of cohesion and friction angle are obvious,and the cohesion increases as the friction angle decreases in the same shear direction.