DETERMINATION OF DEPENDENCE OF GEOMETRIC PARAMETERS OF DRAWN STOPES (UNDERCUTS) FOR IMPLEMENTING TECNOLOGIES OF ACTIVE CONTROL OF MOUNTAIN MASSIF STATE
Authors:   Branch for Physics of Mining Processes of the M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine, Kosenko Andrii , Khorolskyi Andrii ,   Branch for Physics of Mining Processes of the M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine
Published: January 2023

Purpose. Increasing the efficiency of mining of rich iron ores by sublevel caving methods based on the development of the technology of active control of the state of a mountain massif, which will ensure the stability of the outcrops of exposure of drawn stopes (undercuts)and the quality of the mined ore mass. Methodology. To achieve the goal, a complex of modern research methods has been used, which includes the analysis of literary sources, design and construction documentation and practice of developing iron ore deposits at great depths, theoretical generalization of laboratory and industrial experiments, the method of functional characteristics for determining the permissible sizes of structural elements of underground mining methods, systemic economic, graph-analytical and correlation analysis. Results. It has been established that the volumes of drawn stopes (undercuts) with flat inclined and vertical exposures are characterized by a larger volume than those with flat horizontal and vertical exposures. Also, the maximum possible stable parameters are determined for the exposure of the drawn stopes (undercuts), which are formed with the help of smooth blasting. Scientific novelty. Reserves for increasing the efficiency of extraction of rich iron ores by the sublevel caving methods have been determined based on the study of the dependences of geometric parameters of the depth of drawn stopes (undercuts) and the intensity of stoping. Due to substantiation of the above parameters, the intensification of the processes of stoping is carried out, which is an integral part of the active control of the state of a rock massif during underground mining of iron ore deposits. Practical significance. The developed technological solutions allow to increase the volume of pure ore extraction by 5–51%, depending on the mining-geological, mining-technical and geomechanical conditions of the development of rich iron ore deposits and the intensity of stoping and, as a result, to reduce losses by 2.6–4.6% and ore weakening by 2.8–5.2%, to improve absolute quality of the extracted ore mass by 0.8–1.5%, and to increase the economic efficiency of the development of mining units by10.1–27.5%. Conclusions. It has been established that during the development of deposits of rich iron ores with a strength coefficient of f=4–6, an average and below average stability and a thickness of 15–40 m, which are concentrated in the depth range of 1200–1400 m, it becomes possible to form exposure of drawn stopes (undercuts) with a volume of up to 70% of the main stock of the stoping panel, with an increase in the intensity of the technological process of ore drawingup to 8.8 t/m2 per day.