Applications of Rock Fracture Mechanics

Abstract

A survey is given of the many and varied areas of engineering and science which involve the existence, creation or prevention of fracture in rock-like materials. These encompass central activities like quarrying and construction, safety and excavation for tunnels and mines, drilling and fracturing for extraction of oil, gas or thermal energy; other applications include specialty (e.g., ornamental) use of rock or the phenomenology associated with structural geology and earthquake regions, illustrating the vast scale variations in rock studies. Scale and stress/material state are emphasised heavily in contrasting specimens used for laboratory measurements of fracture toughness with the state of representative samples in rock masses; it is even shown that material decohesion plays a negligible role in the overall energy balance of many processes, especially when most work is done, directly or frictionally, to overcome large confining stresses. The relative (energy) efficiency of various rock-breaking techniques is evaluated and some innovations are described. The status of analysis and design procedures for rock fracturing applications is discussed: the potential of finite element and surface integral techniques is put in proper perspective and ongoing/needed developments are outlined, in the context of primary applications.