ABSTRACT
One of the difficult problems in geological science and mining engineering is the fracture modelling of rock-material. Macro-fracture mechanics is very difficult to apply to rock-material, because it does not take into account the complexity of microstructures of the rock-material itself nor the variability of conditions affecting the rock-material. In this chapter, the authors introduce their studies on fractal models of rock micro-fractures. In Irwin’s approach to fracture mechanics for brittle fractures, the critical crack extension force may be written in the form Gcrit=2rs, where rs represents the surface energy per unit apparent macro-metric area. In rock fracture, transgranular brittle fracture is a common phenomenon because of micro-voids and micro-cracks existing in rock masses. The fracture profiles of intergranular and transgranular fractures are often found on fracture surfaces of a rock. Local stress concentrations at micro-voids, micro-cracks, and inclusions etc. are the causes of transgranular fracture.
