Periodic character of failure near openings in high-stress rock mass conditions

Rock mass failure at a great depth near underground openings often has a zonal character. The mechanism of this phenomenon consists in the periodic character of the stresses in the surrounding rock mass and the development of tensile macrocracks at the places (zones) of maximum tangential stresses. A mathematical model of a highly stressed rock mass is developed on the basis of the principles of defect medium mechanics and non-equilibrium thermodynamics. A method of determining the model parameters has also been developed and a satisfactory correspondence between the experimental research on faulted zonal structures near to openings at great depths and the mathematical model calculation has been achieved. The main relationships between the width of the cracking zones and the rock mass strength property have also been determined.