ДОСЛІДЖЕННЯ СТІЙКОСТІ ВІДКАТНИХ ШТРЕКІВ КРУТИХ ВУГІЛЬНИХ ПЛАСТІВ НА ВИЇМКОВИХ ДІЛЬНИЦЯХ ГЛИБОКОЇ ШАХТИ

Abstract

Purpose of work. Investigation of maingates stability in different methods of protection on the extraction layouts of a deep coal mine, which develops steeply inclined coal seams. Methods. To achieve this goal, mine experimental observation of maingates stability performed. Conditions for their maintenance are evaluated by the magnitude of the convergence of the side rocks on the contour and changes in the cross-sectional area of the gateroads. Results. As a result of the research the conditions of maingates stability in steep coal seams in protection by pillars or timber sets are substantiated. It is recorded that in the zone of influence of extraction operations, at a distance of l <60 m behind the mining face with the considered methods of protection, the support of the maingates is deformed within the yielding limits and has characteristic flexures the side of hanging wall. At a distance of l≥60 m, the cross-sectional area of the maingates is reduced to 50% of the initial values, and the amount of roof to floor convergence exceeds the flexibility of the support. The increase displacement of rock mass on the contour of the supported roadway behind the mining face depends on the strength and geometry of the secondary support structures above the maingate. Novelty. It is experimentally established that the change in the cross-sectional area of the maingate during protection by timber sets occurs linearly with increasing length of the extraction layout. Practical significance. To ensure the maingates stability, it is advisable to use non-pillar methods of protection, when using yielding secondary support systemsabove the roadway, or backfilling.