Coupled Hydro-Mechanical Behaviour of Rock Joints During Normal and Shear Loading

Abstract The hydraulic conductivity of rock joints is an important parameter controlling fluid flow in various engineering applications. shearing and normal loading have significant effects on joints, the property which mainly controlled by aperture. Despite importance hydro-mechanical behaviour fundamental micro-scale processes leading to macro-scale observations remain unexplored partly due difficulties with situ measurement aperture its complex relation roughness contact area. Therefore, this study, a series experiments coupling deformability direct shear are performed varying at different stresses. Along measuring stress rate, time-lapse X-ray micro-computed tomography carried out explore evolution joint area during experiments. results show that well correlated mean profiles. Such correlation, however, not apparent for experiment where under high stresses, rate decreases continually indicating damaged asperities hinder flow. trend average mechanical following some cases, follows very closely throughout process. In addition, reveal despite increase stress, it physically possible reach full even artificially well-mated samples 10 MPa. Finally, new correlation proposed relate aperture, roughness. estimates experimental rates both conditions good accuracy.