Rock mechanics is a field of applied science which has become recognised
as a coherent engineering discipline within the last two decades. It
consists of a body of knowledge of the mechanical properties of rock,
various techniques for the analysis of rock stress under some imposed
perturbation, a set of established principles expressing rock mass
response to load, and a logical methodology for applying these notions
and techniques to real physical prob- lems. Some of the areas where
application of rock mechanics concepts have been demonstrated to be of
industrial value include surface and subsurface construction, mining and
other methods of mineral recovery, geothermal energy recovery and
subsurface hazardous waste isolation. In many cases, the pressures of
industrial demand for rigour and precision in project or process design
have led to rapid evolution of the engineering discipline, and general
improvement in its basis in both the geosciences and engineering
mechanics. An intellectual commitment in some outstanding research
centres to the proper development of rock mechanics has now resulted in
a capacity for engineering design in rock not conceivable two decades
ago. Mining engineering is an obvious candidate for application of rock
mechanics principles in the design of excavations generated by mineral
extrac- tion. A primary concern in mining operations, either on surface
or underground, is loosely termed 'ground control', i. e.