Research on the Fractal Dimension of the Orientation Pole Distribution for Rock Mass Joint

The spatial distribution of joint orientations features self-similarity. Based on the fractal theory, a new method for meshing of Schmidt pole diagram has been established to study the fractal dimension of the orientation pole distribution of joint. Meshing of Schmidt pole diagram by equal area is performed in both circumferential and radial directions. When the cycle number n is set, the circle is evenly divided with n diameter lines to obtain 2n sectors of equal area; meanwhile the radius R is divided n times to obtain n rings, and specific ring radii are set to perform meshing of Schmidt pole diagram by equal area, thus obtaining different side lengths of cells and corresponding number of cells occupied by poles; on this basis the fractal dimension of joints was calculated. This method is applied to the research on the fractal dimension of joints in rock mass of mine. The results of the research showed that the method with fewer parameters made the process in which the fractal dimension of the orientation pole distribution of joint was solved simply and easy to operate, and calculating the fractal dimension of the orientation pole distribution for joint by this method could better describe the dispersity and complexity of the orientation distribution of joint.