Experimental and numerical investigations on the shear behavior of a jointed rock mass

The original forming process of the earth crust is companied with internal in situ stress, which gradually complicates while the earth crust evolves with geological conformation movements, leading to the generation of large amounts of faults, joints and fissures. These structural planes, to some extent, remarkably reduce the strengths of rock mass, including the shear behavior. In this paper, the authors report a physical model test on jointed rock mass under direct shear stress state and also adopt a numerical method, Discontinuous Deformation Analysis for Rock Failure (DDARF), to simulate the shear failure process, the variation of stresses and displacements of some key monitoring points. The comparative analysis demonstrates that the numerical results are favorable with those obtained in the physical model test. Therefore, it is concluded that the method of DDARF could effectively simulate the shear behavior of jointed rock mass. Furthermore, other than the original physical model test, the numerical models with echelon joints under different axial loadings are also simulated. The crack initiation, extension, coalescence, and the ultimate shear failure are totally investigated, after which the shear behavior of numerical models in different cases are comparatively analyzed.