Change in stability factor of physical model of mining system with regard to location and parameters of clayey interbeds

Modern mine planning and mineral mining increasingly more often uses R&D in substantiation of project designs and to enhance economic efficiency. An actual trend in underground mineral mining is selection of a rational mining system which ensures maximum safety and productivity. The analysis of the stability factor issue is a relevant but complex challenge of science and technology. Stability of underground mine openings and pitwall slopes experiences influence of many various factors, starting from the physical and mechanical parameters of rock mass and finishing with drilling and blasting operations and other processes. Special effect on safety and stability of mine openings is exerted by soft rocks in roof and floor of beds, in pillars and in partings. It is also necessary to take into account clayey interbeds which greatly change the stress–strain behavior of rock mass and affect stability of mine openings. Stability assessment and prediction of possible discontinuity use different methods. This study involves the method of physical modeling which allows reproduction of geomechanical and geotechnical processes. Also, the study selects three systems of mining for the payout salt beds, the roof and floor, and for the parting with clayey interbeds. The mining systems differ by the geometry of openings and by the depth of mining. In case of each mining system, the influence of location of clayey interbeds on the stability factor of pillars in salt rock masses was analyzed. The main result of the study is the determined stability factor of the model at different parameters of clayey interbeds. Additionally, the typical mechanisms of discontinuities in the model at different location and number of clayey interbeds are revealed.