Numerical modeling of mechanical behaviors of fractured transversely isotropic rock masses

The mechanical behaviors of fractured rock masses, which contains one set of parallel fractures, are macroscopically transversely isotropic. In this paper, a series of numerical simulations using PFC3D were conducted to investigate the effects of geometrical parameters such as inclination angle (ß), fracture diameter (D), fracture intensity (P32), and Fisher constant (?), on the mechanical behavior of the fractured transversely isotropic rock mass under uniaxial compression. The results showed that the relationship between the mechanical properties of transversely isotropic rocks and ß exhibited a U-shape relationship. Four failure modes could be found: sliding or splitting across inherent fractures (SS), sliding along inherent fractures (SL), splitting along inherent fractures (SP), and mixed-mode (M). The fracture diameter (D), fracture intensity (P32), and the Fisher constant (?) have significant effects on the anisotropy of mechanical properties. The change in anisotropic behavior is directly proportional to the increase in fractured geometrical parameters (D, P32, and ?). Finally, the anisotropic ratio (AR) is introduced to reveal the degree of anisotropy of the fractured transversely isotropic rock masses.