Оцінка стійкості гірничих виробок при ударних навантаженнях

Abstract

Purpose of work. The purpose of the research is to determine the conditions for ensuring the stability of mine workings in the coal massif under the action of shock loads. Methods. To achieve this goal, analytical studies were performed using the basic provisions of classical mechanics and the theory of elasticity. In laboratory studies, experimental samples of crushed rock were used, which were placed in a steel cylinder. Results. In the course of experimental research, the influence of the impact force and the impact pulse of the falling load on the response of the plane on a pliable basis with inhomogeneous, piece-sized, fragmented rock was studied. It is recorded that at a constant amount of energy of a single impact (mgH = 14.7 J), when the height of the fall of the load decreases 3 times (from H = 1.5 m to H = 0.5 m), and the mass increases from m = 1.0 kg to m = 3.0 kg, the magnitude of the impact force is reduced by 50%. With an increase in the amount of energy of a single impact (from mgH = 4.9 J to mgH = 44.1 J) at the same height of fall, when the mass of the load increases threefold, there is an increase of 2.5 times the impact force. At a constant amount of energy of a single impact (mgH = const), the displacement of the plane on a pliable base of crushed rock depends on the magnitude of the impact pulse of the falling load. Novelty. It is proved that when there is collapse of lateral rocks in the coal massif containing the production, the force of impact on the surface is proportional to the time of fall of the rock blocks to the time of their impact interaction with the plane. Practical significance. In deep coal mines, as a result of mining and the probability of shock loads from landslides, to ensure the stability of mine workings in excavation sites, it is advisable to use pliable supports or filling the produced space with crushed rock, which will ensure the integrity of lateral rocks.