Evaluation of Geomechanical Properties of Soft Rock Masses by Laboratory and In Situ Testing

In recent years, the evaluation of geomechanical parameters in rock masses and particularly in soft rock masses has gone through significant improvements. New instruments and equipment for in situ and laboratory tests allow for a more accurate evaluation of the properties of soft rock masses. Advancements in data mining (DM) techniques allow for better tools for decision making. The combination of improved instrumentation and more powerful numerical techniques allow for a better characterization of the geomechanical parameters of rock masses. In this chapter, methodologies for deformability and strength evaluation are presented. Equipment that is frequently used for this is illustrated with emphasis on common techniques in situ and in the laboratory. Results of extensive testing on soft rocks are presented with emphasis on the testing of a very heterogeneous conglomerate rock mass at a dam site in Japan. Conclusions and recommendations are presented at the end of the chapter.