Investigation of the Manifestations of Rock Pressure in a Deep Mine With a Steep Occurrence of Coal Seams

Abstract

The purpose of the work. Investigation of the manifestations of rock pressure in the retractable road of a steep coal seam to ensure the operational state of production and increase the safety of work at the excavation site of a deep coal mine. The research used a comprehensive approach, including analysis and generalization of theoretical and experimental research on this problem, field experiment to study the stability of retractable drifts and processing of experimental data. To assess the stability of the preparatory workings, mine studies were performed to study the manifestations of rock pressure in the retractable drift under different methods of protection, when the magnitude of the displacement of lateral rocks on the contour and change the cross-sectional area of the drift along the excavation section. As a result of the performed researches the conditions of stability of retractable drifts of steep coal seams at protection by fires from wooden sleepers and bushes from risers are substantiated. It is recorded that in the zone of influence of mining works, the fastening in the retractable road is deformed and has characteristic curves from the roof. At a distance of l > 80 m behind the clearing face, the loss of the cross-sectional area of the excavation was about 50 % with the method of protection by bushes from the risers and 30 % with the use of wooden fires. It is experimentally proved that with the method of protection of precinct preparatory workings by rigid wooden structures in the form of bushes from risers, the change of cross-sectional area of the retractable lane behind the treatment face in the area of impact of treatment works occurs linearly with increasing length of the excavation site. To ensure the stability of retractable drifts in a deep coal mine with a steep occurrence of coal seams, it is advisable to use aimless methods of protection, when to support the side rocks are used pliable structures in the form of fires made of wooden sleepers. The use of this method of protection of the preparatory workings can reduce the likelihood of landslides and increase the safety of mining operations.