Tkachuk O. Justification of measures to prevent the collapse of lateral rocks when supporting preparatory workings of steep formations

The dissertation solves the actual scientific task of substantiating measures to prevent roof collapse when supporting preparatory workings in coal mines with steep strata by revealing the features of mechanical injury to miners as a result of geomechanical processes, which are manifested in the coal-bearing massif during unloading and determining the patterns of changes in the potential energy of deformation of protective structures, when at the same time they are transformed in relation to their volume and shape within the limits of the deformation resource, there is an increase in the bearing capacity of the supporting supports, which makes it possible to ensure the functionality of the arch fastening and the safe overall dimensions of the rolling stretches along the length of the mining area and working conditions at workplaces. The idea of the work was to substantiate the measures to prevent collapses in coal mines with steep strata due to the use of deformation properties of side rocks, which are manifested during the unloading of the coal massif and the patterns of changes in the potential energy of deformation of protective structures during their compression, which will allow to preserve the operational condition of the preparatory workings along the length of the mining area and avoid dangerous situations at workplaces associated with mechanical injury to miners. The purpose of the work was to substantiate the measures to prevent the collapse of side rocks during the support of preparatory workings in the mining areas of coal mines that develop steeply falling layers. In the work, the following tasks were set and solved: an analysis of industrial injuries caused by the collapse of side rocks during the support of preparatory works was carried out to justify measures to create safe working conditions for miners at the workplaces of mining areas of coal mines; the conditions of stability of side rocks at excavation sites are determined to justify measures to prevent collapses to create safe working conditions for miners while supporting preparatory works; laboratory studies of the deformation properties of the protective structures of the preparatory workings were performed to ensure the stability of the roof and increase the safety of the miners at the excavation sites; mine experimental studies of the stability of roll-back lines were carried out, taking into account the deformation properties of protective structures and the efficiency of the arch fastening to create safe working conditions for miners; a solution was developed to prevent the collapse of side rocks while supporting preparatory works and mechanical injury of miners at workplaces. The object of the research was the processes of stress-deformed state of side rocks in the coal-bearing massif, as a factor of danger in the maintenance of preparatory mine workings. The subject of the study was the influence of the deformation properties of side rocks and protection structures on the stability of preparatory mine workings in the coal massif. The work used a complex approach, which included: analysis and generalization of known studies; analytical and laboratory studies of the deformation properties of lateral rocks and protective structures; methods of mathematical statistics and planning of experiments; mine instrumental observations of the process of deformation of roll-back stretches and arch flexible fastening along the length of the excavation section; processing, analysis and interpretation of the obtained results.