ГЕОМЕХАНІЧНЕ ОБҐРУНТУВАННЯ РОЗРОБКИ ПОТУЖНИХ ТА ВЕЛЬМИ ПОТУЖНИХ ПОКЛАДІВ БАГАТИХ ЗАЛІЗНИХ РУД В УМОВАХ ЗНАЧНИХ ГЛИБИН

Abstract

Purpose. Improving the quality of the mined ore mass and reducing the operating costs for the extraction of minerals by taking into account the geomechanical state of the ore-rock massif. Methods. A complex method that includes analysis and generalization of previous studies, mine instrumental observations, numerical modeling by the finite element method, analytical studies and statistical data processing. Results. It has been established that the key factors influencing the choice of stable parameters of the structural elements of the stope panels of the stope blocks are: the parameters of the stress-strain state of the stope horizon, determined by the depth of mining, the thickness and dip of the ore deposit, the shape and size of the shear zone of host rocks; the procedure for working out stope panels according to the thickness and strike of the stope block; intensity of development of stocks of compensation spaces. At the same time, the stability of transport drifts and junctions with orts-arrivals depends on the length of their location before the contact of the host rocks of the lying side with the ore deposit, the thickness of the ore deposit and the geological macrostructure of the rocks of the sides, as well as the number of contacts of the stope panel with collapsed host rocks. The maximum possible stable parameters of exposures of compensation chambers, which are formed by explosive breaking of borehole charges, depending on the thickness of the ore deposit and the location of their center from the rocks of the hanging side, have been established. Scientific novelty. For the depth range of 1200–1500 m, the dependences of the stress distribution across the pull of the ore deposit on the horizon of mining have been obtained. Power-law dependences of the equivalent span width of the bottom of the stope panel, equivalent spans of stable horizontal and vertical outcrops on the location of the center of the stope panel along the thickness of the ore deposit on the host rocks of the hanging side have been established. Practical significance. The obtained dependencies allow choosing the most rational technological schemes for the mining of rich iron ore deposits, taking into account the stress-strain state of the ore-rock mass and the location of the stope panel according to the thickness of the deposit.