INFLUENCE OF UNDERMINING ROCK MASS ON THE STATE OF MINE WORKINGS

Abstract

Purpose. Research of influence of shifts of rocks on a condition of mine workings at their undermining by longwalls. Methods. The study used a computer simulation method. The simulation was performed by simulating the process of rock shift. The initial coordinates of the points of the rock mass turned into the final ones. This allowed to build sections of the rock mass after undermining, which characterized its deformed state, as well as graphs of displacements and deformations in the mine workings. Results. The performed simulation showed that during the movement of the longwall, the mine working (drift), which is undermined, consistently falls into the zone of horizontal deformations of tension, compression and complete displacements. After stopping the longwall, part of the mine working near the boundaries of the displacement area will be constantly in the zones of stretching and compression. It is established that at a distance of 40 m in front of the moving face, the mine working is in the least favorable conditions with maximum vertical compression deformations. Under the given conditions the drift for the most part after completion of clearing works is in a zone of full subsidence. This zone is characterized by the maximum possible subsidence and the absence of deformations. The performed researchers showed that the conditions of undermining of the southern field haulage drift of seam l7 proved to be quite favorable. Shifts and deformations did not cause a significant deterioration in the state of mine working, except for the increase of slopes on the edge sections of the subsidence trough, which makes it difficult to carry out electric locomotive rolling. For any other purpose, after minor repairs, the mine working may continue to operate. Scientific novelty. The study of the process of shear by computer simulation allowed to establish the patterns of shear and deformation during undermining of the mine working. This is the first time for the conditions of the Ukrainian Donbass. Practical significance. The obtained results can be used to predict the condition of mine workings that are undermined during the cleaning works in similar conditions. Key words: undermining overlying mine workings, shifts, deformations, zone of full subsidence, subsidence trough.