Deformation properties of rock during subcritical failure

Microstructural investigation of subcritical crack propagation and Fracture Process Zone (FPZ) by the reduction of rock fracture toughness under cyclic loading

“…Such slow and stable (subcritical) crack growth is thought to be responsible for much of the time and deformation-rate-dependent failure characteristics of many materials such as creep. Numerous experimental investigations indicate that subcritical failure of geomaterials, which is characterised by the development of a large number of microcracks, is observed even prior to the appearance of main cracks in loaded specimens (Skripka et al, 1989). To ensure the long-term stability of structures in a rock mass, such as an underground power plant, a cavern for storing liquefied petroleum or natural gas, or a repository for radioactive wastes in underground, it is necessary to know the time-dependent behaviour of the rock.…”