Abstract
The object of research is the processes of controlling the state of side rocks to prevent the collapse of the stratified rock strata in the coal-rock massif containing the workings. The studies carried out made it possible to establish the influence of the rigidity of the guard structures of mine workings on the stability of side rocks in the coal-rock massif. It is proved that as a result of the action of an external compressive load on the supporting lateral rocks, the structure, in the form of a model of bunches made of wooden posts, increases its rigidity until the destruction of the security structure. After that, there is an increase in the convergence of side rocks and their destruction. The change in the stiffness of the crushed rock in the filling massif model, which is used to support the lateral rocks, occurs as a result of the compaction of the original material. This is due to repackaging of crushed rock fractions of different sizes and its additional grinding. As a result of this interaction of the side rocks with the filling massif, the integrity of the roof and soil is ensured and convergence is limited. To assess the stability of side rocks, it is proposed to use a dimensionless stress concentration factor k. This coefficient takes into account the rigidity of the guard structures of the mine workings and the flexural rigidity of the side rocks. It was found that when the values of the coefficient k are close to zero (k→0), there is a loss of stability of the guard structures of mine workings and the destruction of side rocks in the coal-rock massif. The preservation of the integrity of the side rocks and the stability of security structures is ensured at values of k>0.1, which corresponds to the parameters of the pliable supporting structures. Most favorably on the condition of side rocks in the coal-rock massif is influenced by the method of backing up the mined-out space of crushed rock. The use of this method excludes the collapse of side rocks. When solving the problem of stability of mine workings at the stage of making technical decisions, it is necessary to predetermine the issues of rigidity of security structures with deformation characteristics of side rocks.
Highlights
At present, the extraction of coal from deep mines remains promising, despite the growth in the production of alternative energy sources
The world experience of deep mines shows that the efficiency of coal seam development depends on the operational state of mine workings
The practice of using aimless methods for protecting mine workings has shown that when using pillars of coal of various structures made of wood to maintain side rocks in the worked-out area of the excavation area, the satisfied state of the supported workings is not always ensured
Summary
The extraction of coal from deep mines remains promising, despite the growth in the production of alternative energy sources. The destroyed rocks after collapse participate in the formation of loads on the support, as a result of which the cross-section of the supported workings is lost, the ventilation of the excavation areas is disrupted. These negative consequences are the cause of accidents in mines. When solving the problem of the stability of mine workings, it is necessary to predetermine the issues of the rigidity of security structures with the deformation characteristics of side rocks. The solution to this issue is an urgent task of the study. The aim of research is to assess the influence of the rigidity of guard structures of mine workings on the stability of side rocks in a coal-rock massif
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