STRENGTH CHARACTERISTICS OF JOINTED ROCK MASS

Abstract

For safe and sound design of engineering structures in rock masses, it is essential to have knowledge of the mechanical behaviour of the rocks. Designs are carried out according to insitu properties and physical conditions of rocks. Yet unlike other engineering materials, rocks generally present unforeseen problems and pose more challenges to the designer. In this study, the data for failure criterion has been collected from Wang and Kemeny (1995) who conducted polyaxial laboratory test. For predicting the ground condition, the field data has been collected from Goel (1994). For the other strength correlation the data has been collected from Mehrotra (1992, 1996) who conducted both field and laboratory tests. By analysing the above data, new correlations have been developed between : 1. Major principal stress (0-1), intermediate principal stress (0.2), minor principal stress (a.3) and uniaxial crushing strength (qc) to account for the effect of 0.2 in the failure criterion which has not been considered in most of the earlier strength criteria. 2. Uniaxial compressive strength of rock mass (a icmass)' dry rock density (7) and rock mass quality (Q).