Quantitative assessment of earth surface deformations over abandoned mine workings

Abstract

Purpose. The purpose of this work is to analyse and establish the dependencies of maximum deformations (horizontal deformations, inclinations and curvatures) of the earth's surface in the event of possible activation of the rock mass above abandoned (old) mining workings that have been preserved at shallow depths or have been decommissioned during the liquidation of the mine and are associated with coal seam outcrops under deposits. Methodology. The work used the results of instrumental observations over several decades, which were obtained at observation stations. The stations were installed above treatment works in various coal-mining areas of Donbas. For analysis, observation stations were selected, at which the characteristics of the displacement process were obtained during mining operations at shallow depths not exceeding 225 m. The results of observations obtained by UkrNDMI, Donetsk National Technical University and National Mining University were used. To establish quantitative and qualitative patterns, all experimental material will be divided into 3 groups according to the degree of metamorphism of rocks. Results. Based on the research results, dependencies were obtained for determining the maximum deformations (inclinations, curvatures, and horizontal deformations) of the earth's surface in the zone of influence of abandoned mining workings depending on the degree of metamorphism of the undermined coal massif. Scientific novelty. The scientific novelty consists in creating a fundamentally new approach to assessing the degree of danger to the earth's surface of abandoned treatment works, which consists in establishing dependencies that allow quantitatively assessing the magnitude of deformations in the area of damage to the earth's surface with a possible activation of the displacement process above the abandoned treatment works. Practical significance. It is possible to apply the results of the conducted research and the established patterns to assess the degree of danger of abandoned shallow treatment works for the earth's surface and surface objects in the zone of their influence, as well as to select appropriate measures to protect such objects.