Geotechnical correlations for soils and rocks / Геотехнические корреляции для грунтов и горных пород

There is a vast difference between a structural engineer and a geotechnical engineer in terms of the material being used. A structural engineer defines the properties of the concerned material, such as concrete or steel, and carries out only a limited number of control tests according to the required standards. In contrast, the material used by a geotechnical engineer is natural and thus, by definition, it can be spatially heterogeneous and, in composition, it can be multiphasic, discontinuous or even anisotropic. This leaves the geotechnical engineer with no choice but to accept it as it is and to accommodate themselves to it. Moreover, while developments in numerical modeling depend increasingly on specific advanced test parameters, soil testing programs remain limited because of the competition between contractors to reduce costs and time. 

Consequently, geotechnical survey programs are mainly based on commonly used tests that give basic parameters but not necessarily the required ones. To bridge this gap, designers ought to use correlations. The aim of this book is to help these designers in this critical operation; therefore, because the reader is considered a skilled geotechnician, no theoretical aspects are considered here. It must also be emphasized that correlations can never be a substitute for an adequate investigation or a field- or laboratory-testing program. This is particularly important for rocks whose characteristics depend significantly on their discontinuities. As a result, correlations between properties are few and not obvious and must be interpreted with caution. For rocks, the emphasis will be placed on “geological” aspects in order to be taken into account in the establishment of correlations. For both soils and rocks, correlations result from test programs on defined areas, either local or large, so they must be considered as site specific. It must also be emphasized that the tests on which they are based have been performed by skilled practitioners and in full compliance with the standards and the state of the art. <...>