ELASTOPLASTIC MODEL FOR ROCK JOINT CONSIDERING MATCHING AND ADHESIVE CONDITIONS BASED ON CRITICAL STATE CONCEPT

Abstract

 In order to develop underground structure without rock mass collapse or slippage, it is important to construct a constitutive model that can accurately predict the strength and deformation characteristics of rock joint, which are weak areas of the rock mass. For this purpose, it is necessary to consider the geometry of the rock joint’s surface and their matching and adhesive conditions. Therefore, in this study, we conducted whether existing the elasto-plastic model of rock joint based on the critical state concept applied in the Cam-Clay model etc. can take into account differences in matching condition of rock joints, and demonstrated their applicability by analyzing shear tests in which only the initial matching differs. In addition, a new state variable was introduced into the model to take into account adhesion condition, and we conducted the analysis of shear tests with repeated shearing and holding to show that the model is capable of representing stress recovery associated with the development of adhesion.