Evaluation of aperture structure and fluid flow in shear fracture of granite using high-resolution numerical modeling technique

Aperture structure and fluid flow of shear fractures with different shear displacement (1 and 5 mm), which were created in granite under different normal stress (20 and 60 MPa) for a shear plane, were evaluated for 10-100 MPa confining pressure, using high-resolution numerical modeling technique. Aperture structure was heterogeneous and fluid flow occurred in preferential flow paths for all the shear fractures under the confining pressure. For shear fractures created under 20 MPa normal stress, aperture structure was characterized by contact points clustered in a few specific regions, and which caused clear channels where fluid flow occurred preferentially, despite of different shear displacement. On the other hand, for a shear fracture with 1 mm shear displacement, which was created under 60 MPa normal stress, aperture structure was characterized by no clear channel although large clustered contact points were observed, and which caused tortuous flow paths. Additionally, for a shear fracture with 5 mm shear displacement, which was also created under 60 MPa normal stress, aperture structure was characterized by smaller clustered contact points, and fluid flow occurred less tortuous flow paths.