Abstract
Introduction. The impact of mining and technological conditions on the deformations of the host rocks around the mine workings is being determined. The Karaganda coal mines use seamless technological schemes for preparing and excavating formations while maintaining preparatory workings on the boundary with the collapsed rocks of the worked-out space, which are characterized by difficult maintenance conditions due to increased residual rock reference pressure. The purpose of the research: is to substantiate the parameters for maintaining workings behind the lava at the boundary with the collapsed rocks of the worked-out space during the mining of coal seams with two-level anchoring. Research methods and materials. It consists in maintaining the production for the entire period of operation, ensuring the effective operation of the two-level anchorage in the area of influence of the cleaning works, which will allow the reuse of this production during the preparation of the cleaning front. The results. The parameters for maintaining workings behind the lava at the boundary with the collapsed rocks of the worked-out space with two-level fastening have been established to reduce the influence of negative factors. Discussion of research results. It follows from the research results that technological measures can improve the quality of fastening the mountain range. The two-level fastening will allow to stabilize the condition of the coupled elongated faces, ensuring safe mining operations, and reduce pressure from adjacent faces. It is proved that in order to maintain a stable condition of the worked-out space at the boundary of the impact of mining operations behind the lava, it is necessary to place deep anchors. Rope anchors must be placed in the area of a rock mass that does not undergo stratification, in which a bridge-forming fastening beam is formed, preventing the collapse of the worked-out space and the displacement of the massif along the section of the mine workings. Conclusion. Geomechanical substantiation of the parameters on models based on normal stresses during two-level fastening of mine workings has been performed. Empirical correlations of an increase in the area of rock detachment in sewage treatment plants with an increased intensity of stress-strain state have been revealed. Conclusions. Studies have been conducted to establish the parameters for maintaining workings behind the lava at the boundary with the collapsed rocks of the worked-out space with two-level fastening. When developing coal deposits within the boundaries of the cross-section of mine workings with complex mining, geological and mining-technological conditions, it is necessary to provide two-level anchoring of deep-lying deposits traversed by the formation.