TABLE OF CONTENTS In this chapter, we will set the scene for the consideration of engineering in the natural material, rock. Most of our engineering materials (with the exception of timbers and soil) are manufactured and tested to specification. Subject to correct quality control, we can then be sure that the engineering material in question has a given set of properties which are used in the design process. However, rock is extremely old compared to all other engineering materials: its age is measured in millions of years and it has undergone significant mechanical, thermal and chemical activity.
We will describe in the following sections the ramifications of the rock's history for engineering, starting with rock as an engineering material and following with a discussion of the conditions in natural rock environments. In Section 2.3, we will discuss explicity the influence of geological history on five of the most important aspects of rock mechanics; and, later on, we will explain more directly (in the context of stresses and strains) the concepts of continuity, homogeneity and isotropy of rock material and rock masses.
One of the most important, and often frequently neglected, aspects of rock mechanics and rock engineering is that we are utilizing an existing material which is usually highly variable. This is demonstrated in Figs 2.1 Figs 2.2 Figs 2.3. The rock will be used either as a building material so the structure will be made of rock, or a structure will be built on
