Eastern Mining Research Articles

Diagnosis of ecological security and the spatial heterogeneity of its driving factors in the mining-impacted watershed, based on ecosystem health-risk-services framework

A comprehensive diagnosis of ecological security (ES) and its driving mechanisms in the watershed under mining influence is essential for the conservation and restoration of watershed ecosystems. Few studies have comprehensively evaluated ES by considering the condition of the ecosystem itself, the ecological function it provides, and the risk it faces. Therefore, by innovatively synthesizing ecosystem health (EH), ecological risk (ER), and ecosystem services (ESs), an ES evaluation framework based on EH-ER-ESs was constructed. Based on quantifying the ES of a typical watershed with mines clustered in China’s Northern Sand Prevention Belt, a spatial correlation analysis was used to elucidate the spatial differentiation characteristic of ES and verify the necessity of the evaluation framework. The driving mechanism of ES and the spatial heterogeneity of its key driving factors were explored using the Geodetector model and the geographically-weighted regression model. The results show that (1) ES was generally medium-security, and very low-security areas (8.16%) were mainly concentrated in the eastern mining aggregation areas. (2) ES showed high-high and low-low spatial clusters. Overall, ES was positively correlated with EH and ESs, while negatively correlated with ER, but there were individual cases of “high health-low security” and “high services-low security”, and combining EH, ER, and ESs to diagnose ES comprehensively was necessary. (3) Drought index, vegetation cover, distance from mining land, population density, and CONTAG were the key driving factors of ES. The explanatory power of factor interactions was higher than that of single factors. The impact of driving factors showed significant spatial heterogeneity, with the effects of mine agglomeration on ES primarily concentrated in the east. The EH-ER-ESs framework can be used for ES evaluation in other ecosystems, and the findings provide important guidance for conducting integrated watershed management.

Effect of slope angle on fractured rock masses under combined influence of variable rainfall infiltration and excavation unloading

Intense precipitation infiltration and intricate excavation processes are crucial factors that impact the stability and security of towering and steep rock slopes within mining sites. The primary aim of this research was to investigate the progression of cumulative failure within a cracked rock formation, considering the combined effects of precipitation and excavation activities. The study was conducted in the Huangniuqian eastern mining area of the Dexing Copper Mine in Jiangxi Province, China. An engineering geological investigation was conducted, a physical model experiment was performed, numerical calculations and theoretical analysis were conducted using the matrix discrete element method (MatDEM), and the deformation characteristics and the effect of the slope angle of a fractured rock mass under different scenarios were examined. The failure and instability mechanisms of the fractured rock mass under three slope angle models were analyzed. The experimental results indicate that as the slope angle increases, the combined effect of rainfall infiltration and excavation unloading is reduced. A novel approach to simulating unsaturated seepage in a rock mass, based on the van Genuchten model (VGM), has been developed. Compared to the vertical displacement observed in a similar physical experiment, the average relative errors associated with the slope angles of 45°, 50°, and 55° were 2.094%, 1.916%, and 2.328%, respectively. Accordingly, the combined effect of rainfall and excavation was determined using the proposed method. Moreover, the accuracy of the numerical simulation was validated. The findings contribute to the seepage field in a meaningful way, offering insight that can inform and enhance existing methods and theories for research on the underlying mechanism of ultra-high and steep rock slope instability, which can inform the development of more effective risk management strategies.

Study on Driving Factors for Changes in the Subsidence Funnel Area of Brine-bearing Layers in the Eastern Mining Area of the Qarhan Salt Lake

Study on Driving Factors for Changes in the Subsidence Funnel Area of Brine-bearing Layers in the Eastern Mining Area of the Qarhan Salt Lake

Electrical Structure between the Main and Eastern Deposits of the Bayan Obo Mine: Results from Time-Domain CSEM Methods

Bayan Obo is a well-known polymetallic deposit containing significant quantities of rare earth elements, niobium, thorium, and iron. However, the epoch in which mineralization occurred and the mineralization process are still debated due to the complex nature of its mineralization and geological evolution. Inadequate geophysical exploration has further contributed to this lack of clarity surrounding critical issues, such as the deep link between the main orebody and the eastern orebody, the form and distribution of the extensive dolomite, and the geologic structures in the area. Therefore, we implemented the time-domain controlled-source electromagnetic method (CSEM) to acquire electrical structures at depths down to 2.5 km between the Main and Eastern mines. According to the inverted resistivity structure, in conjunction with existing geological and drilling data, we classified the main lithologies and faults based on their resistivity characteristics. Overall, the mineralized carbonatite reflects high to moderately high resistivity. The mineralized carbonatite dips overall from north to south, with a maximum extension depth not exceeding 1.5 km, and its range of occurrence is controlled by nearly east–west-striking faults distributed along the bounding line between the roof and floor rocks. The Main and Eastern mines are connected at depth, but the morphology and position of the ore bodies have significantly changed due to multiple phases of tectonic activity. The electrical structure does not reveal any obvious syncline structures, further refuting the traditional view that the Bayan syncline controls ore formation.

Intangible resources as the basis of intelligent support in effective decision-making at all life-cycle stages of an investment and construction project

Improving approaches to the management of an investment and construction project at all stages of its life cycle, including justification of investments, engineering surveys, architectural construction and organisational-technological design, construction, operation, decommissioning, demolition and disposal of the facility, including in conditions of uncertainty and risks, represents a key strategic direction for the development of enterprises. The problem of improving the efficiency of managing the company intangible assets appears relevant, since the efficiency of decisions, in particular, and the efficiency of the enterprise as a whole, largely depends on its solution. The study used methods of a system analysis, statistical-comparative and economic-mathematical methods, as well as the methods of economic and statistical analysis of indicators, characterising intangible assets, including the ranking method. The authors studied the life cycle features of an investment and construction project for enterprises of the mining and processing complex. The stage phases of the investment and construction project, linked to the specifics of the Far Eastern mining industry, are considered. The need for a detailed structuring of life cycle phases and stages for an investment and construction project for a digital intelligent support of effective decision-making, as well as for a use of the potential of intangible resources of performers, is substantiated. In this paper, the developing Soyuznoye graphite deposit (Dalgrafit LLC) is used to design a sequence of processes and procedures for the implementation of the considered project. Based on the existing potential of enterprise intangible resources, management measures are proposed aimed at improving project management processes with the possibility of digitalising individual business processes of the enterprise.

Effects of land reclamation on soil organic carbon and its components in reclaimed coal mining subsidence areas

The accumulation of soil organic carbon (SOC) is crucial for the development and ecosystem function restoration of reclaimed mine soils (RMSs). To optimize reclamation management practices, this study aims to explore the factors and underlying mechanisms influencing the recovery of SOC and its components in RMSs from a systemic perspective using complex network theory (CNT). This study focused on coal mining subsidence areas in the eastern mining regions of China, comparing reclaimed cultivated land with surrounding non-subsided cultivated land. Soil samples were collected at depths of 0–20 cm, 20–40 cm, and 40–60 cm, and 25 soil indicators were measured. CNT was applied to explore the intricate relationships between soil indicators and to identify the key factors and underlying mechanisms influencing SOC and its components in RMSs. The results revealed that the compaction-induced soil structural damage during the reclamation process led to a chain reaction, resulting in increased soil bulk density (11.92 % to 15.03 %), finer soil particles (5.00 % to 9.88 % more clay and silt), and enhanced SOC mineralization (SOC decreased by 10.70 % to 15.62 % with a lower C/N ratio by 2.30 % to 28.55 %). Microbial activity also decreased, with a 6.25 % to 13.16 % drop in MBC and a 0.91 % to 27.68 % decrease in enzyme activity. The utilization of active SOC fractions by more adaptable bacterial communities was crucial within this chain reaction process. The intermediate role of soil structure in the RMS ecosystem, particularly in carbon cycling, becomes more prominent. RMSs exhibited heightened sensitivity to soil structure changes, with the response of microorganisms and enzymes to soil structure changes being pivotal. In the carbon cycling process of RMSs, microbial-driven enzyme activity in response to soil structure was more critical during SOC transformation, while the role of physical-chemical protection and microbial inhibition mediated by iron‑aluminum oxides became more pronounced in stabilizing SOC.

Comparative Analysis of Mining Damage Evaluation Methods for Mining Buildings

In the eastern mining areas of China, coal mining under buildings is more common. In order to alleviate the contradiction between coal mining under buildings and the relationship between workers and farmers, it is necessary to evaluate the degree of damage to buildings in a more objective and scientific way. Taking the buildings in the surface movement basin in Fengfeng Mining District of Handan City as the research object, 15 residential buildings with different degrees of damage were selected as sampling points, and data including four surface movement deformation parameters and five parameters of the buildings' own attributes were collected. In order to objectively calculate the influence of each indicator, two methods, namely principal component analysis and AHP entropy weighting, were used to calculate the influence of the indicators on the damage of the buildings. The results show that the index system selected in the paper is scientific and objective, with the building's own attributes accounting for 0.57. In the evaluation model using principal component analysis, the evaluation of the building damage evaluation results exactly matches the evaluation of the field survey results, which proves the feasibility of applying the method to the evaluation of mining damage in mining areas. The significance of Bartlett's test of 0.228 showed that the indicators were extremely uncorrelated, proving that the AHP entropy method of assigning weights is applicable to the evaluation of mining damage to buildings in mining areas in an indicator system where the indicators are weakly correlated.

A Study on Disasters Induced by Head-On Ejection in High-Speed Driving under the Influence of Roof Drainage

During the gob-side entry driving of the Jurassic coal seam in Western China, ejection disasters occur under the influence of roof drainage, which rarely appear in the eastern mining area. To address this problem, a method combining theoretical analysis, numerical simulation, and field monitoring was used to study the disaster induced by head-on ejection during speedy driving under the influence of roof drainage in the context of gob-side entry driving of the 2202 auxiliary haulage roadway in a mine. A calculation model for the critical energy conditions for disasters induced by head-on ejection was established. The relationships between the driving velocity and the dynamic and static loads on the driving face and the disasters induced by ejection were clarified under the influence of roof drainage. The results indicate that the energy threshold for ejection-induced disaster is 12.23 kJ, and the elastic energy of the driving face induced only by static load fails to reach the energy threshold. When the driving velocity exceeds 5 m/d, microseismic activity in front of the driving face increases in a stepwise manner, and the influence of dynamic load intensifies. The superposition of accumulated elastic energy induced by static load and the energy transmitted by microearthquake to the driving face exceeds the energy threshold, resulting in the risk of ejection-induced disaster. Based on this, measures such as microseismic monitoring in front of the driving face, advanced pulverized coal monitoring, driving speed adjustment, and advanced pressure relief of large-diameter boreholes are adopted to ensure safe driving.

Research on disaster mechanism and correlation of natural earthquake and coal and gas outburst

In recent years, with the increasing of mining depth and mining intensity, coal and gas outburst has become one of the most destructive and harmful dynamic disasters in coal mines. Natural earthquakes are the most destructive natural disasters in the earth’s crust. Both of coal and gas outbursts and natural earthquakes are caused by geo-dynamic processes. In order to research the correlation between coal and gas outburst and natural earthquake, in this manuscript, we took Pingdingshan eastern mining area as the research object. The principles of disaster prevention, seismology, statistics and geophysics were taken as the research basis, both the characteristics and laws of natural earthquakes, and the occurrence laws and characteristics of coal and gas outburst were systematically analyzed by geo-dynamic division method. At the same time, the relationship between the two disasters were established. The research results show that natural earthquake is the accumulation and release process of elastic properties in rock mass, which can induce the abnormal emission of gas in coal mines under specific conditions. Especially the “weak plane structure” in geological structure, which is more likely to lead to the occurrence of coal and gas outburst accidents. Tectonic activities and stress field changes have a unified mechanism for the occurrence of natural earthquake and coal and gas outburst, there are correlations between space and intensity. The research results can also provide new ideas for the prediction work of these two kinds of disasters.

Повышение качества трудовых процессов — средство планомерного снижения рисков травмирования персонала угольного разреза

Relevance of the study is due to a number of factors. Firstly, a typical trend in the activity of coal mines, especially newly opened ones, is an intensive increase in coal production in difficult geological and climatic conditions, while using more and more powerful mining equipment. Secondly, an important circumstance is the use of the shift method of personnel work, which causes its high turnover. These features predetermine an increase in the risk of injury to the coal mines employees. These trends are clearly manifested in the dynamically developing Solntsevo coal mine. In accordance with the general line of the Eastern Mining Company, aimed at further improving production efficiency and occupational safety, a risk management system for negative events is formed at the mine. At the first stage, the employees were introduced to the methodology for identifying hazardous production situations, which they tested in practice in their area of responsibility. The second stage continued mastering this methodology in assessing the risk of identified hazards and developing measures to eliminate them. At the third stage, the employees of the mine began to master the tools for improving the quality of workflows, which is based on an assessment of its main components: personnel, equipment, workflow, and its conditions. Each of these components, in turn, is evaluated against four components. The use of this toolkit allows to identify «narrow» links in the workflow, unsafe operations and actions, the elimination of which reduces the risks of negative events and removes obstacles to efficient work. When testing this toolkit, critical risks were identified, the factors that cause them, measures were developed and taken for implementation to ensure a systematic increase in employee safety when performing the specific operations.

Revitalisering van het mijnverleden in Heerlen door hybride taalculturele praktijken

Revitalisation of Heerlen’s coal mining past through languagecultural practices
 This paper examines how inhabitants of Heerlen relate to the coal mining past of this city through a variety of languagecultural practices that cut across diverse media forms and genres, both textual (poems, rap songs), visual (portrait photography, material commodities), and digital (posts on Facebook, YouTube videos). Through these practices people in Heerlen express, repeat, and renew their individual and collective memories of Heerlen as the centre of the former Eastern Mining District in the twentieth century. We argue that Heerlen is undergoing a process of revitalisation that creates social personae, embedded locally, which are labelled tuupisch (typical). From a normative perspective, performances of identity and memory attributed and/or imagined as linked to this tuup (type) are often parodic and hybrid in character. Through an analysis of various examples, the paper demonstrates the critical potential of such hybrid languagecultural practices to contest dominant perspectives on the city’s mining heritage, to renegotiate place-based identities, and to establish new forms of cultural memory

Herbestemming na de mijnsluiting. De ruimtelijke plangeschiedenis van Parkstad en het Emmaterrein, 1965-1997

Repurposing the Closed Coalmines. Spatial Planning in Parkstad and the Former State Mine Emma, 1965-1997. After the closing of the Dutch coal mines in the former Eastern Mining region in the south-eastern tip of the Netherlands, mining landscapes were wiped clean and industrial relics were all but completely demolished. The radical efficiency of this transition has, in current day, induced a public feeling of remorse over the lost physical proof of the mining period. This article traces how economic and programmatic parameters have guided spatial decision-making during the clean-up operation, and how was dealt with the possibility of preservation of mining relics. The article primarily analyses spatial planning documents responding to the closure of the mines, drawing forward the discourse underlying the restructuring of the region. Secondly, it discusses conceptualization, negotiation and problem solving targeted at the obsoleted mining infrastructure. Focusing on the terrain of former State Mine Emma, an intricate case in the light of this prevailing planning discourse, is put centre stage. The inflexible interdependence between a fixed spatial programme and a financial model is pinpointed as the key factor underlying the protracted redevelopment trajectory.

ЕКОЛОГІЧНІ АСПЕКТИ ДОБУВАННЯ УРАНУ СПОСОБОМПІДЗЕМНОГОСВЕРДЛОВИННОГОВИЛУГОВУВАННЯ(НАПРИКЛАДІМИХАЙЛІВСЬКОГОПОЛІГЕННОГОРОДОВИЩА)

Nuclear energy is an important component of Ukraine's national security. Providing this industry with its own raw materials is one of the priority, long-term tasks of the state. One of the ways to successfully solve this task is to create a favorable investment climate for the involvement of private business entities in the development of the domestic mining industry. In Ukraine, numerous uranium deposits have been explored, which are characterized by relatively small reserves, which is why until recently they were not considered promising for development by the state mining company Eastern Mining and Processing Plant (Zhovti Vody). These deposits are not profitable for development by traditional methods – mining or quarrying, but they can be worked out by the method of underground well leaching. In addition to lower capital costs, this method is also characterized by the fact that it is accompanied by a lower environmental load. The article highlights some aspects of the generalized results of the impact on the environment of the new activity analysis, which involves the creation of a private enterprise for research and industrial development and subsequent extraction of uranium at the Mykhailivka deposit in the Kazankivskyi district of the Mykolaiv region, which relate to the choice of technology evaluation for the extraction of minerals by the method of underground well leaching. The projected enterprise will consist of several temporary mining sites and a stationary industrial site of the processing complex, as well as engineering and transport infrastructure facilities. After working out the deposit, land reclamation and their return to land users and subsoil rehabilitation will be carried out, which will ensure their restoration to the pre-project state. On the territory that may be affected by the construction and operation of the planned enterprise, full-scale field and laboratory geo-ecological investigations were conducted and their results were described.

Does High-Speed Railway Promote High-Quality Development of Enterprises? Evidence from China’s Listed Companies

The high-quality development of enterprises is the micro-foundation of China’s economic growth model from “speed and scale” to “quality and efficiency,” in which China’s transportation infrastructure, especially the high-speed railways (HSRs), plays an indispensable role. We select the propensity score matching and difference in difference (PSM-DID) model as the identification strategy and empirically analyze the impact of the HSR on the high-quality development of enterprises based on empirical data of 1331 A-share listed companies in China. The results show that the HSR has a significant positive impact on the high-quality development of enterprises. This effect is more substantial for enterprises in the Pearl River Delta, the Triangle of Central China, and small and medium-sized cities. The HSR inhibited the high-quality development of enterprises in the mining, culture, sports, and entertainment industries in eastern and central China. The reason is the restriction of the ability to create social and environmental value and the influence of monopolistic competition. The HSR improves labor mobility, capital expansion, and knowledge spillovers, thereby promoting the high-quality development of enterprises. However, new infrastructure mainly improves the high-quality development of enterprises by promoting knowledge spillovers and technological innovation. This paper contributes to the modernization of China’s HSR network and provides essential insights for the HSR to achieve sustainable development goals.

Alternative Soil Substrates Addition Cause Deterioration in Reclaimed Soil Macropore Networks at Eastern Mining Area, China

Minesoil profiles are reconstructed by alternative soil substrates worldwide. However, some substrates lack appropriate soil characteristics and negatively affect the minesoil functions, these negative impacts are largely caused by the deterioration of macropore structure. Nevertheless, the differences of typical substrate characteristics and their influence on the deterioration are unclear. Thus, we present a case study to analyze macropore number, size, connectivity, distribution, and soil permeability of RMSs with three substrates (MSW, YRS and RM), respectively, using industrial X-ray computed tomography. The results indicated that (1) filling of substrates made adverse variations for minesoils in macropore number, Ma, ED, τ and size distribution, and the RMS filled with RM had biggest difference in macropore parameters with NCS, followed by the MSW and YRS. (2) The variations of RMSs in macropore parameters were found to be dominated by a synthetic action of substrate texture, SBD and SOM, where SOM showed significant positive correlations with most macropore parameters other than IM, and clay content and SBD showed significant negative correlations. (3) The macropore network can be linked to SP, among various macropore parameters, Ma, AM, and Ma with ED > 600 μm had significant positive correlations with it. It is suggested that the filling substrates need to be reformed from improving the substrate texture, bulk density, and organic matter content.

Landscape Pattern Vulnerability of the Eastern Hengduan Mountains, China and Response to Elevation and Artificial Disturbance

The eastern Hengduan Mountains are located in the transition zone between the Qinghai-Tibet Plateau and the Sichuan Basin and are important for global biodiversity and water conservation in China. However, their landscape pattern vulnerability index (LVI) and its influencing factors have not been systematically studied. Therefore, the spatial distribution patterns, LVI, and the landscape artificial disturbance intensity (LHAI) of Ganzi Prefecture were analyzed using ArcGIS software based on landscape data and Digital Elevation Model (DEM) digital elevation data. Then, the LVI response to LHAI and elevation was discussed. The results showed that Ganzi Prefecture was dominated by low- and middle-LVI areas, together accounting for 56.45% of the total area. LVI values were highest in the northern regions, followed by the southern and eastern regions. Batang and Derong counties had the highest LVI values. Most areas in Ganzi Prefecture had very low- or low-LHAI values, accounting for 81.48% of the total area, whereas high-LHAI areas accounted for 2.32% of the total area. Both the LVI and LHAI of Ganzi Prefecture had clustered distributions. Spearman analysis indicated that when elevation exceeded 4500 m, it was the most important factor affecting LVI and LHAI. In the range of 4500–5400 m, the relationship between elevation and LVI shifted from a weak positive correlation to a negative correlation, whereas LHAI was positively correlated with elevation. In addition, LVI also responded significantly to LHAI. However, the relationship kept changing as elevation increased. Hence, the ecological vulnerability of high elevation areas above 4500 m deserves greater attention. In addition, pasture areas in the upstream reaches of the Yalong River in the northern region, the coastal area in the downstream reaches of the Jinsha River in the southern region, and the eastern mining area, should be prioritized for protection and restoration. This research provides a basis for appropriate environmental planning mechanisms and policy protections at the landscape level.

Similarity Model Test of Coal Mining under Ordovician Limestone Nappe Aquifer

Ordovician limestone in North China coalfield has the characteristics of karst fissure development and strong water yield. Coal mines in North China have been threatened by Ordovician limestone water for a long time. Taking the mining of 32 coal seam in the first eastern mining area of Qianyingzi coal mine in Anhui Province in China as the engineering geological prototype, this paper uses the self-developed fluid solid coupling similarity model test device to carry out the similarity model test of overburden stress and pore water pressure response of coal mining under Ordovician limestone nappe aquifer. Based on the variation law of pore water pressure and overburden stress in a stope, it can be seen that the variation law of pore water pressure in confined aquifer is jointly affected by two factors: the vertical distance between the monitoring point and coal seam and the horizontal distance between the monitoring point and DF200 fault. According to the analysis of experimental results, the maximum height of a water flowing fracture zone in the stope is fifteen times the mining thickness. Compared with the theoretical calculation results of empirical formula, the coupling effect of seepage field and stress field and the geological structure characteristics of the stope promote the development of a water flowing fracture zone. The research results of this paper have important theoretical and practical significance not only for the safe mining of Qianyingzi coal mine but also for the safe mining of the coal mine facing the double threat of roof Ordovician limestone confined aquifer and reverse fault.

Justification of a medical oxygen production start-up

Introduction. The increase in demand for medical oxygen is causing the interest of entrepreneurs in investing in the development of this field of activity. There is a sufficient number of factories producing technical oxygen in Ukraine. Goal. Determine the list of necessary equipment for the production of medical oxygen and justify the possibility of creating a startup. Method (methodology). The efficiency of the start-up was determined by the method of calculating the net profit brought to the beginning. For this purpose, such data as: inflation and the market value of one cylinder with medical oxygen were forecast three years ahead by month using the method of exponential smoothing. Forecasting was carried out using Excel spreadsheets in the FORECAST.ETS function. The forecast showed a significant decrease in the price of medical oxygen with relatively little fluctuation in inflation. The cost of capital was assumed to be 28.2% per annum. The risk premium is determined by the method of expert assessments. The sum of the cost of capital, inflation and risk premium made up the discount rate. The Repair and Mechanical Plant (hereinafter – RMZ) was taken as the base enterprise, which is part of the Eastern Mining and Processing Plant, subordinate to the Ministry of Energy of Ukraine, based on which further calculations were made. Medical institutions of the cities of Zhovti Voda and Pyatikhatka, Dnipropetrovsk region, and the city of Oleksandria and the village of Petrove, Kirovohrad region, were considered as consumers. The start-up's calculation horizon was determined according to the warranty period of the equipment that will produce medical oxygen, and was three years. Calculation of net reduced profit was performed using Excel spreadsheets. The results. In general, the NPV amounted to UAH 183,303.2, which is 2.956503 times more than the spent funds. The estimated payback period is about 14 months. Scope of application of the results: The conducted research showed that there is a technical and financial possibility to quickly meet the needs of Ukraine in medical oxygen by equipping factories producing technical oxygen with equipment that will convert this oxygen into medical oxygen. Conclusions. An investment project in the form of a startup can be implemented with relatively small amounts and bring profit. The principle of finding the net profit brought to the beginning of the project is effective in conditions where the products are already in demand on the market and have a relatively stable price. A further direction of research should be to determine the limits of application of the NPV calculation in conditions where products or services are new or have significant novelty. The second direction should be the use of the Box-Jenkins forecasting method, with the determination of the lower and upper bounds of the forecast based on the given value of the confidence probability.

Time-Series Analysis and Prediction of Surface Deformation in the Jinchuan Mining Area, Gansu Province, by Using InSAR and CNN–PhLSTM Network

Surface deformation poses a great threat to the safety of Jinchuan mining area production activities. At present, the spatio-temporal evolution law and mechanism of surface deformation in the Jinchuan mining area are unclear, and it is difficult to obtain reliable prediction results using the existing spatio-temporal prediction methods due to the lack of model parameters or relevant data. To solve these problems, this study proposes a new unified convolutional neural network with peephole long short-term memory (CNN-PhLSTM). Small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) technology was used to obtain the spatio-temporal evolution characteristics of surface deformation in the period of 2014–2021. Time series InSAR deformation data are merged into a unified network model in series with a time-distributed CNN segmentation and stacked PhLSTM. The InSAR measurement results are shown to be reliable by comparison and verification with the benchmark and InSAR results of different orbits. The proposed CNN-PhLSTM model was evaluated by mean absolute error and structural similarity (SSIM) evaluation indexes, and was compared with support vector regression (SVR), multilayer perceptron (MLP) and CNN-LSTM models. The results show three continuous subsidence areas, namely the Longshou, second western and third eastern mining areas. The cumulative surface deformation continued to increase from 2014 to 2021. Faults and lithology control the spatial distribution of surface deformation in the Jinchuan mining area. The prediction results demonstrate that the surface deformation range will continue to expand and that time-series surface deformation will show a slow deceleration trend in the next two years.

Investigation on the Height Calculation of Water Flowing Fracture Zone during Coal Mining under Ordovician Limestone Nappe Aquifer

This paper focused on the height calculation of water flowing fracture zone during mining under the Ordovician limestone nappe aquifer. According to the critical conditions of crack arresting under the action of compression‐shear stress, a formula for calculating the height of water flowing fracture zone during mining under the Ordovician limestone nappe aquifer was proposed, which takes tectonic stress, the influence of fault, the mechanical effect of the seepage field on the stress field, and the rock softening with water into consideration. The formula was applied to calculate the height of water flowing fracture zone above panel E3213 in the first eastern mining area of the Qianyingzi coalmine. The comparison between the theoretical calculation and the measured result shows that the formula proposed in this paper is closest to the measured value and further improves the calculation accuracy compared with the previous formulas. This study not only has important theoretical and practical significance for the safe mining of Qianyingzi coalmine, but also has important theoretical and practical significance for the coalmine facing the double threat of Ordovician limestone confined aquifer and reverse fault.