From Engineering Rock Mechanics: An Introduction to the Principles
Having introduced the concepts of stress and strain, we can now consider how the rock reacts to given loads. It is convenient to consider first the intact rock, then the discontinuities and, finally, to consider how they combine to determine the properties of rock masses. Thus, in this chapter, we will discuss the properties of intact rock; in Chapter 7, discontinuities, and in Chapter 8, rock masses.
6.1 The Background to Intact Rock Testing
In rock mechanics, since the early 1960s when it began, more attention has been paid to intact rock than to any other feature of the rock mass. This occurred for two main reasons: the subject has relied heavily on the general topic of the mechanics of solid materials (evolving from rock physics); and the main way in which samples are obtained remote from human-access is by diamond drilling to produce cylindrical cores of rock (which are eminently suitable for testing). These two factors caused a concentration of work on intact rock testing because of the convenience of a well-established background and readily available specimens. The circumstances were probably further reinforced by the general practice of engineers to establish the properties and behaviour of the materials with which they work.
In this chapter, we will be concentrating on the deformability, strength and failure of intact rock. The early emphasis on this subject culminated in 1966 with the discovery of the ability to obtain the complete stress-strain curve. The curve provided previously unknown information on the behaviour...
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