Stress–strain analysis of rock mass during mining of protective pillar of vertical shaft

Abstract

Abstract The implemented studies aim at the geomechanical assessment of safe mining, including safety pillars, within the limits of the protective pillar of shaft RESH in the Irtysh Mine, with estimation of influence exerted by stresses and strains on the rock mass, permanent excavations and ground surface. Slacked replenishment of the raw material resources makes re-extraction of ore reserves from pillars highly topical. It is found that ore loss in mining of the protective pillars reach 30% and above of total reserves at some deposits. Based on the analytical solutions and 3D FEM modeling in terms of the Irtysh Mine, the authors validate feasibility of safe partial extraction of ore reserves from the protective pillar of shaft RESH without aggravating effect on the shaft operation and on the ground surface. The feature of this study is using both specification documents and mathematical modeling, with regard to geology, structure and lithology of a deposit and rock mass, physical and mechanical properties and geometrical complexity of mine objects, which essentially improves studies into stability of underground openings and ground surface. It is found that the basic measure of safety I mining of the protective pillar of shaft RESH is establishing safety pillars.