TABLE OF CONTENTS In this chapter, the first two sections concern the practical aspects of obtaining access to the rock mass for testing, and the general philosophy of the testing requirements-bearing in mind the engineering objective. In the three subsequent sections, there are overviews of tests on intact rock, discontinuities and rock masses. We conclude with a discussion on standardized tests.
In Fig. 11.1, the main ways in which there is physical access to a rock mass are indicated. These are a rock exposure (whether at the surface or underground), lengths of borehole core, and the borehole wall itself after the hole has been drilled. Because the amount of exposed rock is limited and possibly locally altered, testing has tended to be concentrated on the cylindrical lengths of borehole core that are obtained by drilling during a site investigation and by measurements made within the borehole. When studying the illustrations in Fig. 11.1, recall our discussions about intact rock, discontinuities, rock masses, stresses, and the inhomogeneity and anisotropy factors in the previous chapters. What, exactly, is it that we wish to know about the rock mass in order to design and construct a rock engineered structure?
From a rock exposure, it is relatively easy to measure any property of the intact rock. Similarly, the rock mass structure is evident and a...
