To The PRoBlem of SeleCTINg veRTICAl ShAfTS loCATIoN wITh ComBINeD geoTeChNology of DeveloPINg DePoSITS Purpose. Justification and development of scientific and methodological provisions and recommendations for determining the rational location of vertical shafts with the combined method of mining mineral deposits (the com bined geotechnology), taking into account the new manmade impact factor: the open pit space, as well as contact of weakened rocks with the open pit, the presence of groundbased open pit facilities and communications) with ap probation at the mine of the Zhairem MCC JSC (the Republic of Kazakhstan). methodology. When performing the studies on determining the location of vertical shafts in the combined geo technology conditions (transition from open pit to the underground method), the calculation method of the geome chanical model of the massif according to P. S. Shpakov classification is used that allows using the numericalanalyt ical method to estimate stability of slopes for the open pit boards of arbitrary shape. findings. The algorithms for stepbystep, sequential, local optimization of qualitative characteristics and quanti tative parameters for selecting the area of rational and safe location of vertical shafts and a model of the combined geotechnology using opening schemes of vertical shafts are proposed. The method for calculating and assessing stabil ity of open pit slopes for open pit boards of arbitrary shape for the geomechanical model of a heterogeneous massif for 4 types of computational schemes is considered. The results of scientific and experimental studies in the conditions of the Ushkatyn3 deposit (the Republic of Kazakhstan) allowed determining the zones of rock displacement around the pit and establishing safe distances for vertical shafts from the edge of the pit. originality. Studies for determining the rational and safe location of vertical shafts with the combined geotechnol ogy, taking into account new technological factors: open pit space, areas of weakened rocks contacting the open pit, landbased open pit facilities, communications, and others. The model which allows determining the vertical shafts location in the combined geotechnology is developed. There are extended methodological provisions for calculating and assessing stability of the pit slopes for the geomechanical model of the heterogeneous massif which allow estab lishing the zones of the rock displacements and collapse on the earth surface. Practical value. The proposed methodological guidelines and recommendations for selecting the rational place for laying vertical shafts, a model of the combined geotechnology when opening with vertical shafts, the ways of solving specific engineering and geomechanical tasks will improve the efficiency of using the combined geotechnology in the course of further development of fields that assume openunderground mining.

Purpose. Developing an efficient and high accuracy methodology of observing the earth surface deformations when mining minerals by the underground method. methods. Experimental graphoanalytical methods as well as mathematical modeling were applied. findings. There is presented a methodology and results of processing the data of observations of the earth surface displacements when mining coal at Kostenko mine of the Coal Department of ArcelorMittal Temirtau JSC, Kara ganda Coal Basin. The displacement measurements were performed at points of the small geodetic network using the GNSS technologies with accuracy acceptable for the satellite geodetic network of class 1. The results confirm the GNSS methods effectiveness in studying the earth surface displacements in coal mine conditions. Displacement vectors of the GNSS points were determined; numerical values of the relative vertical and horizontal displacements of the points were obtained. originality. A new technique for making geodesic measurements was developed when studying the earth surface displacements during its underworking by means of building local small geodynamic networks. For the first time the observations of the earth surface displacements due to its undermining in the territory of the Karaganda coal basin were carried out not along the profile lines but as a result of a detailed surface survey. Practical value. The proposed method for performing geodetic measurements using the GNSS technology to study the earth displacements has made it possible to determine the parameters of the displacement process with a high degree of accuracy and can serve as the basis for organizing geodetic monitoring at all the mines of the Kara ganda coal basin. The main tool for monitoring manmade processes was a network of specially designed benchmarks in the field. With systematic monitoring, when initially there are implemented the measures to form a geodynamic polygon, the greatest degree of prediction of the risks of field exploitation is achieved.

Purpose. Development of a digital model of the stress-strain state of a rock mass during the extraction of coal by an underground method to predict the displacement of the earth’s surface. Methodology. The proposed technique is based on modeling the stress-strain state of a rock mass using the finite element method. Computer simulation of the stress-strain state of the rock massif was carried out in the area of lavas worked out in previous years in layers with the index K of the Karaganda suite of the mine named after Kostenko of the Karaganda coal basin, where instrumental surveying measurements were previously made to monitor the vectors and numerical values of the displacements of the earth’s surface undermined by mining. Findings. The reliability of the obtained finite element model of a rock mass for predicting the process of displacement of rocks and the earth’s surface is confirmed by the results of full-scale instrumental mine surveying measurements on the earth’s surface. Originality. For the first time, a method has been proposed for predicting the shifts of points on the earth’s surface, taking into account the physical and mechanical properties of rocks, based on a finite element model of a rock mass. A new approach was applied to assess the reliability of the model of the stress-strain state of a rock mass based on a comparison of the results obtained with the data of instrumental mine surveying. Practical value. A technique for computer simulation of the stress-strain state of a rock mass during the extraction of hard coal at the mine named after Kostenko, owned by one of the world’s leading steel producers, JSC ArcelorMittal. For modeling, a site was chosen in the area of lava mining along the coal seams of the Karaganda Formation of seams, starting from the K18 seam to the K10 seam, that is, a rock mass with a depth of more than 700 m. Previously, within this area a series of instrumental surveying observations was carried out of the displacement of the earth’s surface during the working out of these lavas using the method of roof management – complete collapse. The obtained values of vertical displacements of a point on the earth’s surface according to the results of computer simulation of the stress-strain state of a rock mass correspond to the data of field mine surveying observations of displacements of the same point, which confirms the reliability of the constructed model.

Subject of the study are various research works which are carried out concerning issues of degassing, ventilation, management of gas release, etc. The following methods were used for the study: analysis, generalization, experimental works. Purpose is summarizing the experience of gas emission control in complex mining and geological conditions of mines in a number of Karaganda Basin (Republic of Kazakhstan) in the work of high-productivity mines, where the level of absolute gas content reaches very high values. In conclusion of the study it should be noted the experimental work with a total duration of 5 months in four faces at three mines of JSC "ArcelorMittal Temirtau" СD showed that the allowable methane content in the outgoing jets of faces and mine sections of 1.3% creates conditions for more rhythmic and uninterrupted operation of mine sections, compared with the limit methane content of 1.0%. The use of this modern high-precision system allows continuous quality control of the mine's atmosphere and promptly and automatically cut off electricity in areas with high methane content or violations of the ventilation mode (reduction of air supply).

Purpose. The research purpose is to substantiate a rational technology for mining steep-dipping ore bodies based on a complex of geomechanical studies in combined mining of deposits. Methods. Analysis of existing constructive methods for calculating the optimal mining system parameters when mining under-open-pit ore reserves in the zone of influence of surface mining operations, taking into account the natural stress-strain state of the rock mass. Numerical modeling is used to study the geomechanical processes occurring in the mass during the mining of under-open-pit reserves of steep-dipping ore bodies in order to substantiate the mining system with ore shrinkage. The geotechnical mapping of mine workings is conducted directly in the face to determine the mass rating. Findings. The calculation of the optimal parameters for the stope chamber, inter-chamber and inter-level pillars based on a complex of geomechanical studies has shown that the more intense horizontal stresses act in the bottom of the blocks and in the inter-block pillars, in which a large number of board gates have been driven. Originality. For the first time, using high-precision programs and given the nonuniform distribution of horizontal and vertical stresses acting in the mass for the Abyz Mine conditions, it has been revealed that when mining an individual block, the maximum horizontal stresses around the mined-out space reach 10-15 MPa; when mining a group of blocks – 20-25 MPa. Practical implications. The research results can be used in planning and mining with shrinkage of steep-dipping ore bodies during mining of under-open-pit reserves.