Geodynamic safety when increasing the depth of underground mining of ore deposits

Abstract

Statement of the problem (relevance of the paper): the paper describes main scientific and practical results of studies on increasing geodynamic safety, while increasing the depth of underground mining of ore deposits, using operational control data and the forecast for the stressed state of the rock mass with various dynamic signs of rock pressure, and prevention of rock bursts. Using the example of ore deposits in Ukraine, we analyzed physical properties of rocks and new hypothesis of rock pressure, taking into account the relation between the excavation of ore and rocks and time and area, determining parameters of structural elements of development strategies. Purpose of the paper: the paper aims at increasing geodynamic safety, when increasing the depth of ore deposit underground mining, by controlling and forecasting the stressed state of the rock mass with various dynamic signs of rock pressure, and by preventing rock bursts. Methods used: we applied advanced methods of mine, laboratory and experimental studies, theoretical and physical simulation, and analysis and generalization of the results of studies using standard and recommended techniques. Novelty: novel elements include the systematization of technological solutions for managing developed areas of the mine, taking into account the technology-related factors affecting the energy state of the mass, and showing ways to minimize its impact on the technology of ore and nonmetallic mineral resources mining. The result: the paper proposes to change the impact rate of the technology-related state of the mass formed by subsequent, contiguous mined-out areas, a method for destroying the rock pillars separating their cavities, which reduces the energy tension of the mass by 6 times and the secondary water cut of the ore deposits in the lying side of the mine field. This makes it possible to carry out preparatory excavations without the use of supports and to increase a stope area by 1.5–2 times. The change in the shape of the mined area of the mine by the formation of unloading cracks makes it possible to reduce the energy parameters of the mass by 0.3 times, when developing the three underlying floors over ore deposits.