Abstract
Problem Statement (Relevance): This paper describes the main scientific and practical results of a study into enhancement of the geodynamic safety in the underground mining of complex structure deposits achieved through the application of stress monitoring and forecasting data on the rock mass with various rock pressure dynamics, as well as through certain preventive measures, including the prevention of rock bumps. Using the example of complex structure deposits of Ukraine, the physical properties of rock were analyzed, as well as some new rock pressure hypotheses, taking into account the outcrop stability analysis, the deformation and failure patterns, the time and space correlation of ore and rock excavation, and the parameter definition in terms of the structural elements of the development systems. Objectives: This research aims to increase the geodynamic safety in the underground mining of complex structure deposits through the application of stress monitoring and forecasting data on the rock mass with various rock pressure dynamics, as well as through certain preventive measures, including the prevention of rock bumps. Methods Applied: Improved techniques of underground investigations, laboratory and experimental research and mathematical and physical modeling were applied, as well as established and novel methods of theoretical analysis and summarization. Originality: The original features of this research include an established parabolic dependence of the stress coefficient in the chamber walls on the sides of the stripped area (y) on the ratio of its length to its width (x): y = a ∙ x2 + bx (where a and b are coefficients that depend on the geomechanical properties of the rock mass). Findings: The article gives a classification of the stress state of the rock mass according to its rock-bump hazard degree. Thus, an area with η ≤ 0.2 is considered safe; 0.2 <η ≤ 0.3 refers to the third class of rock-bump hazard, 0.3 <η ≤ 0.5 – to the second class, and η> 0.5 – to the first class correspondingly. Practical Relevance: This research provided initial data for the design of underground development system applicable to complex structure deposits depending on the orientation of maximum stresses relative to the mine.
Keywords
Complex structure deposits, underground development, geomechanical safety, rock pressure, rock-bump hazard.
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