GEOMECHANICAL JUSTIFICATION OF THE STABILITY OF DEVELOPMENT WORKINGS UNDER FLOOR HEAVE CONDITIONS

The paper examines the geomechanical patterns governing the loss of stability of development workings affected by floor heave at deep levels of coal mines. The aim of the study was to establish the relationship between the physical and mechanical properties of the near-contour rock mass, stress redistribution after excavation, and the development of plastic deformation in the floor of the roadway. The ventilation roadway 47K₂-W at the Kostenko mine of the Karaganda Coal Basin was selected as the study object. The research combined laboratory testing of rocks, instrumental assessment of strength characteristics, acoustic monitoring, and numerical modeling of the stress-strain state in the RS2 environment. It was found that floor heave is primarily controlled by the low strength of the floor argillites, the reduction of lateral confinement in the near-contour zone, and the formation of a destressed region where weak bedded rocks pass into a plastic state. The results show that roadway stability increases when the entire system “roof - ribs - floor” is stabilized rather than a single element being reinforced. The highest efficiency was demonstrated by combined rock-bolting schemes incorporating side and floor bolts. The obtained results can be used to substantiate support parameters for development workings driven in similar mining and geological conditions.