An essential step in a site characterisation program is the development of a geological model

that captures the geological complexity of the site. This geological site descriptive model is then used as the

basis for developing the ground engineering model which forms the basis for design. Advances in technology

have led to new methods for conducting site investigation and for building the geological site descriptive model.

Examples are provided that highlight the development of a geological site descriptive model and the impact of

the geological complexity on the ground engineering model. <...>

The term Rock Minerals is sufficiently indefinite to permit of considerable latitude in the choice of minerals to be included by it. Besides those that constitute the mass of any rock there are the less abundant though common kinds, as well as occasional, exceptional, ones. In any case the mineral may be an original constituent of the rock or one that has been developed in it subsequent to its formation. Rock Minerals, therefore, embrace not only all primary minerals, but all those of secondary origin produced by any manner of alteration of previously existing minerals.

The purpose of this Handbook is to provide, in highly accessible form, selected critical data for professional and student solid Earth and planetary geophysicists. Coverage of topics and authors were carefully chosen to fulfill these objectives.

The Rock Quality Designation (RQD) index was introduced 20 years ago at a time when rock quality information was usually available only from geologists’ descriptions and the percent of core recovery. The RQD is a modified core recovery percentage in which unrecovered core, fragments and small pieces of rock, and altered rock are not counted so as to downgrade the quality designation of rock containing these features. Although originally developed for predicting tunneling conditions and support requirements, its application was extended to correlation with in situ rock mechanical properties and, in the 1970s, to forming a basic element of several classification systems. Its greatest value, however, remains as an exploratory tool where it serves as a red flag to identify low-RQD zones which deserve greater scrutiny and which may require additional borings or other exploratory work. Case history experience shows that the RQD red flag and subsequent investigations often have resulted in the deepening of foundation levels and the reorientation or complete relocation of proposed engineering structures, including dam foundations, tunnel portals, underground caverns, and power facilities. <...>