Underground Mining Area Research Articles

A method for optimizing the capacity allocation of a photovoltaic-pumped hydro storage system in an abandoned coal mine

The enormous potential of the photovoltaic (PV) sector has aided in the faster attainment of China's “dual-carbon” aim. However, due to a scarcity of land resources and intermittent fluctuations in solar energy, it has been difficult to build large-scale PV bases, and existing PV systems also suffer from unstable power generation and seasonal fluctuations and are unable to be directly connected to the grid for use. However, abandoned mines with huge surface collapse zones and a large underground mining area offer a potential possibility for constructing photovoltaic-pumped hydro storage (PV-PHS) systems and limiting PV variations. Based on the abandoned mine pumbed hydro storage (AMPHS) potential assessment model and the optimized discrete wavelet decomposition algorithm, this study proposes a dynamic cycle optimization method for the PHS regulation capacity in an abandoned mine PV-PHS hybrid system. This approach is able to determine the optimal regulation capacity of AMPHS on a daily scale while limiting the volatility of the PV-PHS hybrid system. The method was applied to an abandoned mine PV-PHS hybrid system in Zaozhuang City, Shandong Province, and the optimal regulation capacity of the AMPHS was determined to be 88 MWh and 100 % elimination of PV generation volatility was achieved. This also reduces the economic cost by roughly 1.94 × 108 CNY. In addition, it is possible to store an average of 2.32 % of the PV power generated and to extend the power generation time by approximately 2.5 h per day. This research is critical for boosting the resource use of abandoned mines, and establishing the comprehensive usage model of new energy and abandoned mine resources.

Ventilation of large section blind headings under conditions of changing ore load size

Relevance. The need to ensure safe working conditions in the working areas of underground mines. Stagnant zones with low air velocities can be formed in large section blind heading behind the ore bulk when ore is shipped by mining machines. There is a possibility of the formation of local gas accumulations and their abrupt removal later in such stagnant zones due to the unsteadiness of accumulation and transfer of gas impurities in a blind heading. A sharp removal of gas will lead to contamination of the load-haul-dump operators’ workplace. Aim. To identify removal of exhaust gases in large section blind headings in conditions of changing ore load size. Objects. Large section blind headings with of complex geometry. Methods. Three-dimensional numerical simulation of unsteady turbulent flow of a gas-air mixture in the Ansys CFX, visualization and analysis of simulation data in the Wolfram Mathematica. Results. The paper presents the results of mathematical modeling of ventilation of large section blind headings of complex geometry under conditions of changing ore load size formed during mining operations by the load-haul-dump machines with an internal combustion engine. It is shown that either a single vortex is formed that ventilates the blind headings space, or a stagnant zone behind the bulk ore, which is characterized by a relatively low intensity of mass transfer. Vortex formation depends on the height of the ore bulk. The authors have obtained the dependences of the change in the average concentration of exhaust gases at the outlet of the blind headings space on the operating time of the machine. They determined the dependence of the correction volume coefficient on the geometric parameters of the blind headings. An analytical model of the removal of gases from the blind headings space under conditions of changing bulk ore volume is obtained. The expression of increment in gas concentration on an operator’s workplace makes it possible to derive formula to find maximum time of load-haul dump operation in a stope such that gas concentration is never higher than maximum allowable concentration.

Hydrogeochemical evolution patterns of diverse water bodies in mining area driven by large-scale open-pit combined underground mining-taking Pingshuo Mining Area as an example

Large-scale open-pit combined underground mining activities (OUM) not only reshape the original topography, geomorphology, and hydrogeochemical environment of the mining area, but also alter the regional water cycle conditions. However, due to the complexity arising from the coexistence of two coal mining technologies (open-pit and underground mining), the hydrological environmental effects remain unclear. Here, we selected the Pingshuo Mining Area in China, one of the most modernized open-pit combined underground mining regions, as the focus of our research. We comprehensively employed mathematical statistics, Piper diagram, Gibbs model, ion combination ratio, principal component analysis and other methods to compare the hydrochemistry and isotope data of different water bodies before (2006) and after (2021) large-scale mining. The changing patterns of hydrochemical characteristics of different water bodies and their main controlling factors in mining area driven by OUM were analyzed and identified, revealing the water circulation mechanism under the background of long-term coal mining. The results showed that: (1) The chemical composition of water has changed greatly due to large-scale coal mining. The hydrochemical types of Quaternary and Permian-Carboniferous aquifers shifted from predominantly HCO3-Ca·Mg before intensive mining to primarily HCO3·SO4-Ca·Mg, HCO3-Na, HCO3·SO4-Na·Mg, and HCO3·SO4-Ca·Mg, HCO3-Ca·Na, HCO3·SO4-Mg·Ca post-mining. Variations in the hydrochemical types of surface water were found to be complex and diverse. (2) Coal mining activities promote the dissolution of silicate rock and sodium-bearing evaporites, enhancing the strength and scale of positive alternating adsorption of cations. The oxidation of pyrite, dissolution of silicate weathering, and the leaching of coal gangue were identified as the main reasons for the significant increase of SO42−, while decarbonation in confined aquifers led to a decrease in HCO3−. (3) Results from the principal component analysis and stable isotopes demonstrated the hydraulic connection among surface water, Quaternary aquifers, and Permian-Carboniferous aquifers induced by long-term OUM. The research findings provide a reference basis for the coordinated development of coal and water in the Pingshuo Mining Area and other open-pit combined underground mining areas.

Verification of correction factors for determining mean annual levels of radon in underground facilities

The first verification of a tool developed to improve the work of controlling bodies, managers and employees of underground facilities subject to radiation protection requirements was conducted. The recommended values of correction factors were verified using archival results of measurements conducted for the Institute of Occupational Medicine in Łódź in seven underground workplaces in Poland over exposure periods of a month (10,8678 data) and a quarter of a year (53,688 data). In a cave two groups of monthly factors, produced estimates with almost 70% to 99% consistency with the measured values. Along tourist routes located in mines, a similar fit was obtained using three groups of correction factors for measurement results from March, June and July. In the extraction areas of active underground mines, the best fit was produced by factors calculated as averages for spaces varying in the degree of insulation and ventilation method, while in other departments of mining plants, by correction factors recommended for facilities equipped with mechanical ventilation systems. All the quarterly correction factors produced the best fit between estimated mean annual concentrations and measurement results obtained in the second quarter of the calendar year. A wide variation in result consistency (from 20–30 to 65–80%) obtained for two underground tourist routes in the fourth quarter of the year demonstrates that it is best not to adopt results from this measurement period (October-December) for estimating mean annual radon concentration using the set of quarterly correction factors.

Effect of microwave on coupled rheological and mechanical properties of cemented tailings backfill

Cement tailings backfill (CTB) is a mixture of tailings, binders and water that is widely utilized to fill underground mining areas. Once placed, the CTB needs to provide adequate ground support as soon as possible to improve mining efficiency. Microwave heating can accelerate the curing process of CTB, thereby improving the mechanical performance of CTB. However, if the CTB slurry is under the heating condition, the early hydration reaction process of the mixture can be accelerated, consuming more water in the CTB materials and thus resulting in reduced fluidity. Therefore, this study proposes an experimental scheme to incorporate microwave heating into the preparing and curing of CTB, so as to realize the improvement of the mechanical strength of CTB body under the condition of also ensuring the fluidity of fresh CTB. The results indicate that with the appropriate microwave heating time (2–4 min) and power (600 W) applied, both the flowing ability and strength in the plastic and hardened CTB can be improved. The improvement in fluidity of CTB is ascribed to the intensification of molecular thermal movement, while the enhancement in strength of CTB is due to the acceleration of binder hydration progress. The current study can also contribute to further practical application of microwave heating in the preparation process of CTB before it is placed into underground mined-out areas.

Spatiotemporal change characteristics of vegetation coverage in Shangwan Mine of China's Shendong Mining Area.

The coal mining might cause the disturbance to the vegetation and the disturbance impacts might exist the differences for different areas, and few literatures compared and analyzed different disturbed areas based on the location of the mining face, and paid attention to the post mining self-healing effects of vegetation. Here, this paper selected the GaoFen multispectral images during 2017-2021 to study different areas of Shangwan Mine which includes the old mining area more than 5 years after mining, the new working face underground mined in 2018 and 2019, the natural growth control area and the open-pit mining affected area. The spatiotemporal changes of the surface fraction vegetation coverage (FVC) were analyzed in each area and the correlation between vegetation coverage and climatic factors was studied. The results showed that: (1) The overall vegetation coverage showed a moderate decrease trend in fluctuation from 2017 to 2021. The Open-pit mining affected areas showed the largest decline, reaching 68.3%. The FVC in the underground mining areas had a downward trend, but self-healing effect after mining was also observed. (2) The overall FVC in the study area was positively correlated with the number of precipitation days. (3) There were differences in the sensitivity to mining disturbance for different landform in the underground mining areas. (4) Although the FVC in the Old mining areas had recovered to the level of Natural growth control area, but the annual fluctuation was larger, which might mean lower ecological stability.

Integrated stable S isotope, microbial and hydrochemical analysis of hydrogen sulphide origin in groundwater from the Legnica-Głogów Copper District, Poland

Hydrogen sulphide (H2S) was first reported in 2010 in an underground mining area of the Legnica-Głogów Copper District (LGCD). However, during the deposit exploration and exploitation stage in 1970, H2S was not detected. Previous studies have not indicated the origin of H2S in LGCD mine waters. Indirect evidence has suggested that, most likely, H2S migrated with the groundwater from the Main Dolomite aquifer to the mine galleries through cracks in the separating anhydrite and halite layers resulting from long-term mining operations. Interdisciplinary studies have been conducted to confirm this hypothesis. Investigations of the δ34S in H2S of 12 groundwater samples taken from leakages from cracks in galleries and drilled boreholes showed high isotopic similarity to H2S in natural gas and S-organic compounds of oil from petroleum reservoirs in the Main Dolomite unit, where this gas was generated in high volumes mainly as a result of thermochemical sulphate reduction (TSR). Microbial investigations of mine water indicated the presence of Desulfitobacterales, Desulfobacterales, Desulfotomaculales, Desulfovibrionales, and Desulfuromonadia as possible indicators of contact between the analysed water and rocks inhabited by sulphur-reducing bacteria and Halothiobacillales, as an indicator of contact between water and salt. Hydrochemical analysis revealed that water flowing out of mine galleries and boreholes has a higher salinity than groundwater that is naturally associated with the horizon where mines operate; this phenomenon is associated with H2S occurrence. This investigation confirmed the hypothesis that the H2S in the LGCD mines originates mainly from the Main Dolomite aquifer. Furthermore, this study confirms that a multifaceted approach is necessary to answer complex geochemical questions in mining.

Investigation and analysis of spatial distribution of brine concentration in the underground brine mining area of the northern coastal area of Weifang City

Investigation and analysis of spatial distribution of brine concentration in the underground brine mining area of the northern coastal area of Weifang City

A new approach to ensuring acceptable working conditions in mines using ventilation equipment

The study analyses issues of rational maintenance of the breathable and explosion-proof air environment in the working areas of underground mines using mine ventilation equipment. The article justifies the need for a paradigm shift in the ventilation system and a transition from diluting harmful substances in the air throughout the working area to a multi-zone division of free air space and maintaining acceptable air quality in the breathing zones of miners through the displacement/advective transfer.

Mechanical properties under triaxial compression of coal gangue-fly ash cemented backfill after cured at different temperatures

The triaxial mechanical properties of cemented backfill are the key indicators that affect the stability of cemented backfill in underground mining areas, and the high temperature environment in mines has become one of the main factors affecting the mechanical properties of cemented backfill. Understanding the triaxial mechanical properties of cemented backfill in high temperature environments is crucial for the stability of cemented backfill in mining areas. To investigate the effect of temperature on the mechanical characteristics of cemented backfill under triaxial compression, triaxial compression experiments were done on coal gangue-fly ash cemented backfill that had been cured at three temperatures (20 °C, 35 °C, and 50 °C). The deviatoric stress-strain curve of cemented backfill under triaxial compression was produced, its deformation parameters, dilatancy, and failure characteristics were investigated, and a more appropriate strength criteria was proposed. The research results indicate that, peak strength and dilatancy stress of cemented backfill under the same confining pressure decrease first and then increase as the curing temperature increases. The failure patterns of cemented backfill under triaxial compression will exhibit layered splitting failure except tension and shear failure since the curing temperature has increased. By comparing it with several other criteria, the Mogi-Coulomb strength criteria was found to be a good reflection of the failure strength properties of cemented backfill cured at different temperatures under triaxial compression. With curing temperature rises, internal friction angle of cemented backfill steadily lowers, while the cohesion first decreases and subsequently increases. The alteration in cohesion is consistent with the peak strength change rule, illustrating that the primary factor influencing peak strength of cemented backfill is cohesion. This study provides a good theoretical reference value for guiding the design of deep mine filling and optimizing the mixture ratio of cemented backfill.

Human and environmental exposure to rare earth elements in gold mining areas in the northeastern Amazon

Rudimentary methods are used to exploit gold (Au) in several artisanal mines in the Amazon, producing hazardous wastes that may pose risks of contamination by rare earth elements (REEs). The objectives of this study were to quantify the concentrations of REEs and assess their environmental and human health risks in artisanal Au mining areas in the northeastern Amazon. Thus, 25 samples of soils and mining wastes were collected in underground, colluvial, and cyanidation exploration sites, as well as in a natural forest that was considered as a reference area. The concentrations of REEs were quantified using alkaline fusion and inductively coupled plasma mass spectrometry, and the results were used to estimate pollution indices and risks associated with the contaminants. All REEs showed higher concentrations in waste deposition areas than in the reference area, especially Ce, Sc, Nd, La, Pr, Sm, and Eu. Pollution and enrichment levels were higher in the underground and cyanidation mining areas, with very high contamination factors (6.2–27) for Ce, Eu, La, Nd, Pr, Sm, and Sc, and significant to very high enrichment factors (5.5–20) for Ce, La, Nd, Pr, and Sc. The ecological risk indices varied from moderate (167.3) to high (365.7) in the most polluted sites, but risks to human health were low in all areas studied. The results of this study indicate that artisanal Au mining has the potential to cause contamination, enrichment, and ecological risks by REEs in the northeastern Amazon. Mitigation measures should be implemented to protect the environment from the negative impacts of these contaminants.

Numerical Study of Resistance Loss and Erosive Wear during Pipe Transport of Paste Slurry

Cemented paste backfill (CPB) as a solid waste treatment technology that prepares tailings as aggregate into a highly concentrated slurry to be transported to the underground mining area, is now widely used in mines. However, the pipeline resistance loss and erosion wear during CPB slurry transportation considering the coupling effect of inlet velocities, viscosities, and particle sizes have not yet been well evaluated and analyzed. Hence, the CFD-based three-dimensional network simulation of CPB slurry flow in an L-shaped pipe at different combinations of the three parameters was developed using COMSOL Multiphysics software. The results showed that the pipe resistance loss was most affected by the inlet velocity and viscosity, with the minimum pipe resistance loss occurring at an inlet velocity of 1.5 m/s, a viscosity of 2.0 Pa·s, and a particle size of 150 μm. In particular, pipe erosion wear was severest at the bend and was positively correlated with inlet velocity and particle size, and negatively correlated with slurry viscosity, with maximum pipe erosion wear occurring at an inlet velocity of 3.5 m/s, a viscosity of 3.0 Pa·s, and a particle size of 2000 μm. The findings would be important for the design of the CPB pipeline transportation, which will improve the safety and economic level of a mine.

Long-Term Impact of Ground Deformation on Vegetation in an Underground Mining Area: Its Mechanism and Suggestions for Revegetation

Ground deformation is one of the most common geological disasters arising in underground mining areas, and mining-induced environmental impacts have resulted in numerous concerns, especially the impacts on the surface vegetation. The evaluation of mining-induced impacts on vegetation is beneficial to revegetation in mining areas; however, the impacts of ground deformation have seldom been systematically evaluated and explained on long time scales despite the long-term existence of ground deformation in underground mining areas. To address this, in this study a vegetation-soil-climate (VSC) model was developed to evaluate the long-term impacts of ground deformation on vegetation, and to reveal its mechanism. The results revealed that the long-term impacts of ground deformation on vegetation result from the degradation of the vegetation and soil when ground deformation occurs, which thereby limits the growth and succession of plants after the ground deformation has occurred. The intensity of the long-term impacts is determined by the severity of the ground deformation, but the duration, climate factors, the substrate conditions of the vegetation and soil before the deformation, and the natural change coefficient of the vegetation and soil are also relevant. Furthermore, the characteristics of the long-term impacts on vegetation were analyzed, and a framework for implementing revegetation and suggestions for the supervision of revegetation in underground mining areas are presented based on the characteristics. The results of this study provide insights into the impacts of mining-induced ground deformation on vegetation on long time scales, considering the comprehensive interactions between the vegetation and other environmental factors, and provide theoretical support for revegetation in underground mining areas.

Application of Geomechanical Classification Systems in a Tourist Mine for Establishing Strategies within 3G’s Model

Stability problems in rock masses are one of the main causes of subsidence events in underground mining areas. Zaruma, in the South of Ecuador, is characterised by mineral wealth, in which 65% of the population depends directly on artisanal mining activity. However, mineral extraction, without technical considerations and in many cases illegal, has negatively impacted the stability of tunnels generated under the city’s urban area, reporting subsidence events in recent years. The aim of this study is to geomechanically characterise the main gallery of the tourist mine “El Sexmo” using two classic methods of geomechanical classification for the configuration of a model that complies with the 3G’s (geotourism, geoconservation, and geoeducation) and supports the culture of sustainability in all areas of the sector. The methodology consists of (i) a field study design, (ii) a geological–geomechanical survey of the rock mass of a tourist mine using rock mass rating (RMR) and the Q-Barton index, and (iii) establishing a 3G’s model for sustainable development. The results reveal that 100% of the rock mass of the tourist mine presents a rock quality classified as “Fair” (class III) by the RMR method, while, via the Q-Barton method, 92.9% of the rock mass obtains a “Poor” rating, except for station S05, rated “Very Poor”. Furthermore, the study proposes additional support measures for three specific stations based on Q-Barton assessments, including fibre-reinforced sprayed concrete and bolting and reinforced ribs of sprayed concrete, considering that the mine is more than 500 years old and maintains geological features for geoeducation in geotechnical mining. Technical and social problems demand an innovative strategy, which, in this work, focuses on the 3G’s model based on the quintuple innovation helix to develop sustainable underground geotourism.

The Synergistic Effect of Topographic Factors and Vegetation Indices on the Underground Coal Mine Utilizing Unmanned Aerial Vehicle Remote Sensing.

Understanding the synergistic effect between topography and vegetation in the underground coal mine is of great significance for the ecological restoration and sustainable development of mining areas. This paper took advantage of unmanned aerial vehicle (UAV) remote sensing to obtain high-precision topographic factors (i.e., digital elevation model (DEM), slope, and aspect) in the Shangwan Coal Mine. Then, a normalized difference vegetation index (NDVI) was calculated utilizing Landsat images from 2017 to 2021, and the NDVI with the same spatial resolution as the slope and aspect was acquired by down-sampling. Finally, the synergistic effect of topography and vegetation in the underground mining area was revealed by dividing the topography obtained using high-precision data into 21 types. The results show that: (1) the vegetation cover was dominated by "slightly low-VC", "medium-VC", and "slightly high-VC" in the study area, and there was a positive correlation between the slope and NDVI when the slope was more than 5°. (2) When the slope was slight, the aspect had less influence on the vegetation growth. When the slope was larger, the influence of the aspect increased in the study area. (3) "Rapidly steep-semi-sunny slope" was the most suitable combination for the vegetation growth in the study area. This paper revealed the relationship between the topography and vegetation. In addition, it provided a scientific and effective foundation for decision-making of ecological restoration in the underground coal mine.

Development of stability criteria for risk reduction in the Desa Kubang Tangah in Sawahlunto Indonesia

Sawahlunto City is one of 19 cities/regencies in West Sumatra Province that is highly vulnerable to landslides. The topography is steeply wavy, including in Kubang Tangah village, Lembah Segar subdistrict. The city already has a land use plan that limits urban development. During the Dutch East Indies government, Sawalunto was known as a coal mining city. This city did not develop for a time after coal mining stopped. Studies that provide scientific considerations are needed, considering that this city has limited land, is prone to landslides, and is an underground mining area. As such, geological studies and geotechnical investigations are carried out to obtain the necessary data, followed by an analysis of the potential for landslides in the Kubang Tangah village area, which, in April 2023, experienced a landslide disaster resulting in road infrastructure and several houses being damaged. Furthermore, based on the analysis of safety factor criteria using the limit equilibrium method, which compares driving forces and slope-resisting forces, it is proposed to be considered in plans to develop settlements and road infrastructure to reduce the risk of landslides.

Effects evaluation of Heat Stress Index and workload to miner’s fatigue level in underground gold mining area PT Dwinad Nusa Sejahtera

Mining is an activity with a high risk of accidents in open pit and underground mining sites. Various factors that cause accidents have been found through accident investigation, such as miners’ fatigue. Miner’s fatigue can be caused by environmental factors and workload that can be controlled to make a safe and comfortable working environment and prevent accidents. This research objective is to evaluate the relationship between environment factors in the form of heat stress index using humidex method and workload to miner’s fatigue level in the underground mining area PT. Dwinad Nusa Sejahtera. This research was done by measuring the working environment to know humidex, workload and miners fatigue level. Working environment conditions in the underground gold mine of PT. Dwinad Nusa Sejahtera is in a hot and humid condition with wet temperature range are 28.5–32.9°C, dry temperature range are 29.7–33.0°C, globe temperature range are 29.7–33.5°C wet bulb globe temperature range are 29.0–32.1°C, relative humidity range are 83.1–100% and humidex are 49.5–59.5°C. Multivariate analysis of miner’s fatigue level in all activity groups shows that the humidex variable gives more significant effects than the workload variable.

SURFACE DEFORMATION MONITORING AND DRIVING FORCE ANALYSIS IN THE YELLOW RIVER DELTA BASED ON PS-INSAR TECHNOLOGY

Abstract. Aiming at the land subsidence in the Yellow River Delta region, based on the Sentinel-1A data of 52 scenes from 2020 to February 2022, Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) were adopted to extract the surface deformation information of the Yellow River Delta region. Firstly, the deformation characteristics of typical subsidence feature points are analyzed, and then the correlation between groundwater, precipitation and land subsidence are analyzed. The result show that the settlement area distribution of the Yellow River Delta is not uniform, mainly distributed in underground brine mining area and oil extraction area, the maximum settlement center is located in Yongan Town, the settlement amount reaches −302.7 mm, the main reason of the settlement is excessive exploitation of underground brine salt. By analyzing the correlation between groundwater, precipitation and land subsidence in the Yellow River Delta, it can be seen that the effect of groundwater content change on land subsidence was the most serious, and the correlation coefficient is 0.875. In general, the subsidence of the Yellow River Delta is mainly caused by the over-exploitation of underground fluids such as fresh water, brine and oil without timely compensation.

Numerical Simulation of Slope Stability during Underground Excavation Using the Lagrange Element Strength Reduction Method

In this study, the Lagrange element strength reduction method is used to explore slope stability and as an evaluation method of underground mining of end-slope coal in a rock-stability analysis. A numerical analysis model is established herein using the geological conditions for mining in a coordinated open pit with an underground mining area of the Anjialing Open-Pit Mine and Underground No. 2 Mine. Additionally, the evolution law of slope stability in open-pit end-slope mining is studied using the proposed numerical simulation method. According to our findings, the steps show obvious horizontal movement and deformation under the influence of underground mining disturbances. Taking the horizontal displacement at the slope tops of the steps as the deformation index, the entire disturbed slope is divided into four regions: upper, middle-upper, middle-lower, and lower steps. When a step is fully affected by underground mining, its subsidence value first increases rapidly and then slowly. An exponential function is used to reflect the change rule in the step-subsidence value as the working face advances. In the underground mining process, the critical sliding surface of the slope develops along the soft rock or coal seam, showing an L-shaped or a W (double L)-shaped broken line. As the working face advances, the initial position of the sliding mass is unchanged while the cutting position alternately changes up and down in the weak plane. The safety factor suddenly drops when the advancing distance exceeds a certain value.

Engineering-geological zoning of the central area of the Upper Kama Potassium–Magnesium Deposit in view of salt karst propagation

With a view to geological and environmental safety of the central area of the Upper Kama Potassium–Magnesium Salt Deposit, the engineering-geological zoning is performed to identify karst-sensitive land. The zoning is based on two most fundamental factors: hydrogeology and neotectonics. Evaluation of the first factor consisted in determining the thicknesses of suprasalt deposits and the size of fresh groundwater zone by analyzing the data of exploration wells and other geological and hydrogeological materials, as well as calculating the thickness of the separating stratum corresponding to the interval of deposits from the top of the salt stratum to the lower boundary of the zone of fresh groundwater. The analysis of the second, neotectonic, factor was associated with the identification of increased fracturing zones in rock mass based on the grouping of faults and lineaments obtained from the interpretation of cosmic and aerial photographs, as well as from the construction and analysis of digital elevation models during field route observations. The comparison of two factors made it possible to zone the territory of research into areas with different degrees of protection of the salt stratum from the potential development of karst: high, medium and low. Within the areas with a low degree of protection, the further detailed studies of the hydrodynamic regime of groundwater and their interaction with the host rocks are necessary. The described method of engineering-geological zoning can find application to provide natural and technological safety in underground mining areas. The results obtained can be used in design of systems of special-purpose geodetic and hydrogeological monitoring.The research was carried out under the state contract, Topic No. AAAA-A19-119021190076-9.