СТІЙКІСТЬ СКЛЕПІНЧАТОЇ ВИРОБКИ, ЯКУ ПЕРЕТИНАЄ ВУГІЛЬНИЙ ПЛАСТ ПАРАЛЕЛЬНО ДЕННІЙ ПОВЕРХНІ

Abstract

Purpose. The presence of a formation and the difference in the mechanical properties of the host rocks lead to a significant increase in the maximum stresses at the points of the production circuit where the coal seam and the host rocks are connected. At the points of contact between the coal seam and shale, the stability condition becomes the most important. This gives grounds to propose a rational design of the mine fastening: it is necessary to increase its rigidity, and the flexible elements of the fasteners must be installed at the junction of shale and coal. Methodology. Currently, the finite element method (MSE) is the most common method for solving a wide class of problems in the mechanics of a deformable solid in various fields of technology. In mining, ITU is used to solve problems of statics and dynamics of rock massifs. Usually, preference is given, if possible, to flat problems that allow exploring more multiparameter systems. In this article, horizontal workings of considerable length are considered, so their end parts do not affect the middle part of the work and for it the conditions of flat deformation are realized. In this case, for each section perpendicular to the axis of production, it will have the same stress distribution around the contour of production. Therefore, the calculation area for determining the stress distribution around the development is chosen in the form of a square plate of unit thickness, which is perpendicular to the axis of production, and the contour of production is in its center. The edges of the plate are loaded with gravitational pressure, the magnitude of which depends on the mine depth and the density of the mine field rocks. The production circuit is considered free of loads and ties. Thus, to determine the stress distribution around the mine is the problem of a flat stress state. Results. The ray methods was used to investigate the interaction of a plane blast wave with a circular mine production of a minefield. The wave front is parallel to the forming of mining, which is parallel to the day surface. If the horizontal mining of a circular cross-section is of great length, then it can be assumed that the boundary conditions do not affect the stress and strain fields in the vicinity of the central crosssection of the production and we will investigate these fields by formulating a flat problem of the theory of elasticity. Static stress-strain state of the rock in the vicinity of circular production is analyzed using the finite element method. The field of Mises strength conditions (σmiz c ) around the vaulted mine at a depth of 500 m, through which the coal seam passes parallel to the day surface, is analyzed. The presence of a coal seam strongly influences the distribution of Mises strength conditions σmiz c . The formation and the difference in the mechanical properties of the host rocks lead to a sig-nificant increase in the maximum stresses at the points of the circuit where the coal seam and the host rocks meet. At the points of contact between the coal seam and shale, the stability condition acquires the greatest value σmiz c = 2 × 107 Pа. Originality. Due to the use of the finite element method, for the first time a detailed description of the stress-strain state around the vaulted mine, through which the coal seam passes parallel to the day surface, was obtained. Practical value. The developed technique of definition of mining stability conditions gives the basis to offer a rational design of fastening of mining. Using the finite element method, studies of stress fields and displacements around the vaulted mine, through which the coal seam passes parallel to the day surface, were carried out. This allowed to identify dangerous areas on the contour of the production and suggest rational types of fastening structures. References 15, figures 3.