Stability concept of brittle fracture propagation in rock

Abstract The results of brittle fracture propagation studies in rock are presented. Stable and unstable fracture propagation is discussed and it is shown that the transition between these two processes in rock is determined by the critical energy release during fracturing, a concept originally introduced for brittle fracture in metals. The concept of critical energy release is now applied to rock and experimental determination of the critical energy release rate,Ge, for quartzite and norite is reported. The significance ofGe in rock fracture processes is dealt with and its practical applications in mining are outlined.