Experiments with rock: Remarks on strength and stability issues

In the classical work of Fairhurst and co-workers on machine stiffness, it was shown that the failure response of a rock specimen can be a mixture of material and structural behavior. This is due to the development, around peak stress, of a localized region of microcracking called the intrinsic zone, which may be a property of the rock. The inhomogeneity formed by the intrinsic zone has a fundamental importance for defining the system behavior...