ЗІСТАВЛЕННЯ ДЕФОРМАЦІЙНИХ ВЛАСТИВОСТЕЙ ОХОРОННИХ СПОРУД ПІДГОТОВЧИХ ГІРНИЧИХ ВИРОБОК

Abstract

Purpose. Investigate and compare the deformation properties of protective structures in the form of coal pillars and structures made of crushed rock for a justified choice of the protection method, which can make it possible to ensure the stability of side rocks in the coal massif and preparatory works in the mining areas in the coal mine. Methodology. To achieve the goal, laboratory studies were performed on experimental samples subjected to uniaxial compression. For pillars, their thickness was changed, whereas for structures made of crushed rock the thickness of the rock layer was changed at a constant cross-sectional area. Results. As a result of the conducted research, the deformation properties of protective structures that were subjected to uniaxial compression have been determined. A 15% reduction in their stiffness was recorded for pillars, when their thickness h0 was two times changed, and for the external static load, which varied according to a linear dependence. Within the limits of the safe deformation resource, when the relative deformation is in the range of values 0.18≤λ≤0.23, the stability of the pillars and their bearing capacity is ensured. At the same time, the relative change in their volume should not exceed 7-9%. It has been established that exceeding the limit level of the specific potential energy of deformation by an average of 12-14% causes the destruction of coal pillars. For protective structures made of crushed rock with a relative volume change of 0.35≤δV≤0.28, the value of the compaction coefficient of the original material decreases from kcons = 1.5 to kcons = 1.42 with a simultaneous increase in the work of compression and an increase of more than 20% in the specific potential energy of deformation, thanks to which the rigidity of the embedded material and the bearing capacity of protective structures made of crushed rock are ensured. Scientific novelty. The regularities of formation of deformation properties of protective structures under conditions of uniaxial compression, taking into account the change in the specific potential energy of deformation and the relative change in their volume, have been established. Practical significance. In order to ensure the stability of side rocks in the coal massif and preparatory workings at excavation sites in the coal mine, the feasibility of using partial or complete paving of the produced space from crushed rock, which limits the movement of side rocks in the produced space, has been substantiated.