Grigoriev O. Substantiation of parameters of capital workings' protective pillars in a coal mine

On the base of laws of change of the stress-strain state of rock mass around the capital inclined workings, defined for the first time for mining and geological conditions of Belozerskaya Mine an urgent task of determining the acceptable size of safety pillars is decided. On models with equivalent materials the character of convergence change for the two capital workings separated by the pillar, depending on his width is determined. De-pendences of convergence change on thickness of sandstone seam in the roof and distance from him to the foot coal seam are described by exponential functions, and the smallest contour displacements are characteristic ones for models, in which the sand-stone layer is positioned directly in the roof of the coal seam. Based on mathematical modeling of the finite element method, for the first time the regularities of stress distribution within the barrier are established for mining and geo-logical conditions of the mine. The regularities of resize region of inelastic deformation depending on thickness of sandstone seam in the roof and distance from it to the foot of coal seam, which are ex-ponential in nature, are detected. Determined limits of inelastic deformation zone around the workings, a change of which is under the parameters of rock mass, that allowed building the appropriate dependencies. The effectiveness of experimental reducing the size of safety barriers between longwall and pass was 2.5 mln. Hryvnias /year for the one face.