Purpose. The assessment of options for opening and mining the upper tier of Oleniy Ruchey apatite-nepheline deposits and technological solutions development taking into account geomechanical calculations of open pit slopes and benches stability, both on the marginal contour and when changing the design values of the slope parameters, open pit benches and the stability safety factor to establish the marginal maximum accepted under the condition of the values stability. Methodology. Searching for technological solutions of mining is based on the method of mining and geometric analysis of the deposit upper tier, comparison, generalization, systematization, analytical calculations, 3D parametric modeling, three-dimensional numerical modeling of stress-strain state and the rock mass stability by the finite element method. Findings. According to the research results, the optimal development of mining operations has been proposed for an option providing for the minimum overburden ratio. The parameters of the highwall slopes and their elements on the marginal contour and the development of the deposit are recommended according to the option that provides the maximum possible involvement in the development of the adjacent rock mass and pit reserves mining within the existing limits of the open pit mining tap. Originality. It consists in feasibility evaluation of using a rational technology for the development of mining operations according to the option that provides for the minimum overburden ratio and possible mining development schemes for mining open pit reserves with an assessment of the possibility of internal dumping during the development of an open pit. Practical value. The calculations show that for the conditions of a lying side, the normative factor of the slope stability on the marginal contour can be ensured only if they are bank slopes worked along the weakening surfaces, whose cutting should not be permitted.

Purpose. To develop a methodology for assessing the quality of drilling-and-blasting operations when setting the side to the final position. In this regard, it is necessary to study the nature of deformations in the near-side masses of the design open-pit contours and to assess the seismic impact of blast waves in accordance with damage in the near and far zones from the open-pit boundary, as well as the level of generated seismic vibrations. Methodology. A methodology for assessing the quality of drilling-and-blasting operations at the limiting contour of open pits is developed using the analysis of the mining-and-geological conditions of the rocks constituting the field, in-situ surveying of the state of the open-pit sides, analysis of the physical-mechanical properties of the host rocks, analytical studies and instrumental measurements of the blasting effect. Findings. Based on the analytical methods, the calculation and analysis of the seismicity coefficient of the rocks at the field have been performed. By means of instrumental measurement of the blasting effect in open pit, data have been obtained on the seismic impact of blasting operations on the near-side mass. Based on the results of these works, a methodology for assessing drilling-and-blasting operations at the limiting contour of the open pit has been developed. Originality. In this work, to assess the blasting effect, the seismicity coefficient of the rock mass is used, which characterizes the degree of elastic response to external dynamic influence and is a parameter that determines the elastic seismic wave intensity with distance from the site of blasting operations. Based on the calculation, a map of the seismicity coefficient distribution in the open-pit area has been compiled. Using the method of instrumental measurements, which serves to determine the seismic impact of blasting on a rock mass, the degree of blasting effect on a near-side mass has been revealed. This made it possible to develop a method for assessing the blasting quality, based on determining the percentage of permissible deviations in the face drilling quality. Practical value. The results of the work will be used to calculate the safe parameters of conducting the blasting operations when setting the side to the final position. This method for assessing the quality of drilling-and-blasting operations can be applied at any mining enterprise conducting open-cut mining of minerals.