Engineers wishing to build structures on or in rock use the discipline known as rock mechanics. This discipline emerged as a subject in its own right about thirty five years ago, and has developed rapidly ever since. However, rock mechanics is still based to a large extent on analytical techniques that were originally formulated for the mechanical design of structures made from man made materials. The single most important distinction between man-made materials and the natural material rock is that rock contains fractures, of many kinds on many scales; and because the fractures - of whatever kin- represent breaks in the mechanical continuum, they are collectively termed 'discontinuities' . An understanding of the mechanical influence of these discontinuities is essential to all rock engineers. Most of the world is made of rock, and most of the rock near the surface is fractured. The fractures dominate the rock mass geometry, deformation modulus, strength, failure behaviour, permeability, and even the local magnitudes and directions of the in situ stress field. Clearly, an understanding of the presence and mechanics of the discontinuities, both singly and in the rock mass context, is therefore of paramount importance to civil, mining and petroleum engineers. Bearing this in mind, it is surprising that until now there has been no book dedicated specifically to the subject of discontinuity analysis in rock engineering."

All rock masses contain bedding planes, fissures, fractures, joints and other mechanical defects which are here referred to as "discontinuities". The requirement to provide numerical data on discontinuities for engineering design calculations has created the need to apply the mathematical methods of probability theory, statistics, vector analysis and mechanics to a topic that has previously been handled in a largely qualitative way. This book aims to bridge the gap between the descriptive methods of the geologist and the analytical methods of the rock mechanics engineer as applied to discontinuity characteristics. It does not pretend to be the final word on the topic, but rather seeks to explain in simple terms, basic ideas that can be built upon. Advanced undergraduates studying civil, mining and geological engineering and postgraduates pursuing coursework in rock mechanics, soil mechanics and engineering geology should find this a valuable text. It should also serve as a reference tool for practising engineers and geologists faced with the task of collecting, analyzing and applying discontinuity data for the analysis and design of surface and underground excavations in rock associated with a wide range of mining and civil engineering projects. This book should be of interest to undergraduate students studying civil, mining and geological engineering; Msc and PhD students in rock mechanics, soil mechanics, engineering geology, hydro(geo)logy and related subjects; and practising engineers and geologists.