Class I vs Class II stability: a demonstration of size effect

The objectives of this work are to offer an analytical explanation and to present experimental evidence of the Class I “ductile” vs the Class II “brittle” response observed on the global level for rock and rock-like materials. The general basis of the theory is that the potential energy of the system, stored per unit of volume, is converted to fracture energy within the rock, dissipated per unit of area. Consequently, a natural size dependence...