STRENGTH BEHAVIOUR OF JOINTED ROCK MASS THROUGH MODELLING WITH PLASTER OF PARIS

Abstract

Several massive, complicated and difficult to design structure are under construction or planning stages under very complex geological condition in India and around the world. Even small variation in appraisal and design can cost millions. Hence initial development of understanding under control condition is very important and desirable for characteristic and prediction of behavior. It is essential to have a clear understanding of strength and deformation behavior of jointed mass for realistic analysis and rational designing of engineering structure. Rock, like soil, is sufficiently distinct from other engineering materials that the process of design in rock is very complex. In rock structures, the applied loads are often less significant than the forces deriving from redistribution of initial stresses. Hence, the determination of material strength requires as much judgement as measurement. A thorough review of literature on different aspects of jointed rock mass indicate that the behavior of jointed rock mass is influenced by many factors such as location of joints, joint frequency, joint orientation and joint strength. In the present study, an effort has been made to find out the strength of jointed rock mass with different gouge material. The most important factors which govern the strength of rock mass are type of rocks, bedding planes, stress condition, presence of cracks and fissures, nature of joint surfaces and presence of minerals in bedding planes. As the in situ determination of jointed rock mass is costly and time consuming, attempts are being made to predict the strength of rock mass through model test under controlled laboratory condition.