Loading Rate Dependency of Dynamic Responses of Rock Joints at Low Loading Rate

Excerpt

Rock discontinuities, particularly rock joints due to their universality in rock masses, play a dominant role in the behaviors and the properties of rock masses. The mechanical responses of rock joints, such as normal and shear displacements, are often induced by static and dynamic loads. Dynamic loads are commonly in the form of stress wave transmitting across rock masses. Although at a low stress level, a dynamic load may not induce rock material fracturing and fragmentation, it may however, generate significant dynamic responses of rock joints that lead to the large movement at the joint contacts and the instability of the rock masses. In addition, open joints with filling materials (e.g., sand and clay) are likely to be more sensitive due to the low strength and the high deformability of the filling materials. …