Model of deformation of steel arch support in horizontal underground workings of deep mines

Purpose. Development of an adequate model of steel arch support for underground workings of deep coal mines to assess its stress-strain state. Methodology. The study of the deformation of steel arch supports in main workings of deep coal mines, comparing them with the results of analytical studies, considering the peculiarities of the time-dependent geomechanical processes in the rock mass near the face, and development a new mechanical model of the deformation of steel arch support during its loading based on this. The research employed methods of structural mechanics, field studies, and statistical processing of field measurement results. Results. Considering the development of geomechanical processes during the advance of the face, a new two-stage deformation model of steel arch support has been proposed, which operates in the first stage under a regime of specified deformations due to the movement of the contour of the workings, and in the second stage under a regime of specified loading after the loss of stability of the rock at the bottom, which will allow for a reasoned approach to the design of support, justification of its rational form, and ensuring the stability of underground workings in deep mines and quarries. Scientific novelty. Based on the patterns of deformation of steel support in capital workings, a new two-stage deformation model of steel arch support for capital underground workings in coal mines and quarries has been proposed, which corresponds to the conditions of its operation in real conditions. By analyzing the stress-strain state of the arch support, its possible forms have been justified, which have reduced material consumption and are adapted to specific mining and geological conditions. Practical significance. The new model of deformation of steel arch support in coal mines will allow for a reduction in the consumption of steel rolled special profiles used for support production, which is scarce under conditions where the main producers of special profiles – metallurgical plants named after Illich and Azovstal, both located in temporarily occupied Mariupol – have been destroyed. This will also reduce the cost of the extracted mineral resources and increase production efficiency.