Interval non-probabilistic reliability methodfor surrounding jointed rockmass stability of underground caverns

Firstly, the interval values are presented to denote the mechanical parameters of rock mass, which can reflect the uncertain character during determining the parameters. The determining methods are also proposed according to the character of the parameters. Secondly, according to the engineering geological condition and characteristics of plenty of fractures, the block theory is adopted to analyze stability of surrounding rock mass of underground caverns, and an interval non-probabilistic reliability model of surrounding jointed rock mass of underground caverns is also developed based on the stability analysis. Thirdly, the solution of non-probabilistic reliability indexes is performed by means of the interval theory and the one-dimensional optimization algorithm. The synthetic evaluation is carried out through the established reliability evaluation rules. According to the elements of vector analysis method, the numerical software MATLAB is employed to compile the program applicable to underground caverns. The program needs to input joints, measuring point direction, mechanical parameters, vertical wall height of underground caverns and other relevant engineering data, to search existing unstable rock blocks in ranges of underground caverns and to analyze boundary conditions, geometric parameters, failure modes and interval non-probabilistic reliability of each block in turn. Accordingly, sliding direction，non-probabilistic reliability and other relevant information of the key block are obtained. The information will provide guidance for excavation of underground caverns.