Energy Storage and Release of Class I and Class II Rocks

As underground excavations become deeper, violent rock failures associated with the sudden release of elastic energy more prevalent, threatening safety workers and construction equipment. It is important to figure out energy-related failure mechanisms rocks. However, evolution across complete deformation different types rocks effect high confinement on storage are not well understood in literature. In this study, a series cyclic triaxial compression tests were conducted for Class I II investigate confinement-dependent characteristics evolution. The results showed that three identified as behavior changed from brittle ductile. limit was linearly enhanced by confinement. nonlinear increase dissipated at peak stress increasing suggested indicate start brittle–ductile transition. post-peak fracturing process characterized using ratio local withdrawn fracture energy, novel energy-based index proposed quantify intensity rock. This paper presents investigation conversion rock, which may shed light projects.