Abstract
Purpose. To assess the stability of the roof in the excavation space of the excavation area to prevent lateral rock collapses and to justify a set of measures to improve the safety of miners in coal mines. Methods. The study of the stability of the roof was performed on a model of a multi-span beam using analytical calculations and optical modeling. Results. The preserved stability of the roof in the mined space of the coal massif provides conditions for supporting mining operations. Calculations of multi-span horizontal and inclined beams have been performed. The calculations are based on the disclosure of the static uncertainty of beams using the equations of three moments. Reactions in intermediate supports and maximum bending moments along the length of the beam with the same number of intermediate supports have been determined. It has been established that for a uniformly loaded continuous beam with equal spans, the first and last intermediate supports are the most loaded in all cases. To reduce the bending moment in the span of the modeled beam, it is recommended to take into account the strength of the intermediate supports. In optical models, the concentration of tangential stresses in the lateral rocks is determined by the curvature of the contour of the preparatory workings and the bending of the roof along the length of the cleaning working. The maximum concentration of tangential stresses is recorded in the area of supports located around the retreat and ventilation shafts. This situation around the preparatory workings indicates an intensive load on the fasteners. The concentration of stresses leads to roof destruction, collapse and deterioration of the stability of the preparatory workings. In real conditions of coal seam development, the condition of the roof is a determining factor on which the stability of the preparatory workings along the length of the excavation section depends. Novelty. It consists in carrying out a comprehensive study of the stability of the roof in the created recess space. Practical significance. To ensure the stability of the preparatory mine workings on the boundary with the created space of the excavation area, the location of supports is necessary, the stability of which allows limiting the movement of the roof and ensuring a smooth deflection of the overhanging layer of rocks. The maximum effect is achieved when the stiffness of the supporting supports matches the physical and mechanical characteristics of the side rocks. Keywords: roofing, coal massif, extraction station, opening, multi-span beam, load, resistance of intermediate supports bending moment
Published Version
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