Complex limit state criterion for rock masses

The paper presents a complex limit state criterion, which allows to predict limit states of rock masses and its potential transition to discontinuum state. The idea of the complex limit state criterion is based on the fact that the stress-strain state of the rock mass should be evaluated not by one particular failure criterion, but by a system of criteria taking physical specifics of each criterion into account. The proposed limit state criterion is universal and can be used for the evaluation of the rock mass state in the vicinity of any geotechnical structures. The main aim of the paper is to establish a criterion that will accurately separate quasi-continuum states of rock masses from discontinuum ones. This separation can be further used for numerical simulation of geomechanical behavior of rock masses in the vicinity of underground structures using continuum methods, such as the finite element method (FEM), and discrete methods, such as the discrete element method or distinct element method (DEM) in correspondent areas. The application of the proposed complex limit state criterion is demonstrated on the classic examples of rock mass strength/failure assessment in the vicinity of a single mining excavation. The results of the study can be used either for the determination of potential failure zones in the rock mass in the vicinity of underground structures or for the development of specialized CAE software, which are based on coupled FEM-DEM numerical methods. [Figure not available: see fulltext.]