Build your house upon rock." This age-old admonition seems rather superfluous in view of the present trend towards ever larger structures on and within rock formations, as well as the increasing utilization of various rocks as industrial raw material or construction material. These various uses of rocks call for detailed quantitative knowledge of their physical and mechanical properties.
In view of the fact that the defects rather than the properties of the rock itself will be the over-ruling factor in most instances and because of the heterogeneous character of rocks in general, standardized methods of mapping and testing and tabulated data concerning rock properties are widely lacking. The present book goes some way towards satisfying this need. Based on the methods developed at the I.G.E.M. laboratories, U.S.S.R., the book presents methods and techniques used in sampling, testing and determination of rock properties.
The presentation is divided into three main sections. The first deals with rock sampling, physico-mechanical testing and geological investigations connected with sampling, the second with the determination of physical properties of rocks, and the third with their mechanical properties.
The book relates how the frequently inter-related effects ofjointing, weathering and porosity affect the inherent physical and mechanical properties of rocks, and gives detailed descriptions of the methods and relationships used in determining these effects.
Design and construction of structures on or within rock formations depend on the elastic and plastic deformations of the surrounding rock as it interacts with the structure. These properties are to a considerable extent defined by the elasticity modulus and Poisson's ratio. Because of the heterogeneous character of rock, however, these "constants" are found to be rather variable even within individual samples.
The book describes the static and dynamic testing methods, used to determine the compressive, tensile, bending, shearing and impact strength of rocks, as well as their elastic parameters. The results are listed in various tables for a comprehensive range of rock-types and rock-forming minerals. The values so obtained, however, define properties for very small specimens only. To characterize a rock mass as a whole, with all its defects and non-homogeneity would require large static test programmes of an impractical scale. In recent years seismo-acoustic methods have therefore become usual. Seismic methods do not yield data which can be used directly for construction designing, but this drawback is partly overcome by linking static parameters at some characteristic points with the siesmo-acoustic observations for the entire rock mass in order to generalize the obtained data.