Abstract:Land reclamation mitigates the impact of coal mining on grain production in cultivated land.Early prediction of reclaimed crop yields facilitates precision field management and ensures food security.Advances in unmanned aerial vehicle(UAV)platforms and sensor technology enable the acquisition of high spatial and spectral resolution data,making rapid yield estimation feasible.The analysis focuses on soybeans cultivated in reclaimed open-pit coal mine waste dumps within the black soil region.This study evaluates soybean yield estimation models using four methods—multiple linear regression(MLR),random forest regression(RFR),backpropagation neural network(BPNN),and support vector regression(SVR)—with vegetation index(VI),texture index(TI),and combined vegetation-texture index(VTI)as feature variables.The results show that:(1)Compared to using only VI or TI as feature variables,models incorporating both VI and TI demonstrated improved accuracy;(2)Support Vector Regression(SVR)exhibited the best stability and accuracy in yield estimation modeling,achieving R2=0.84,RMSE=0.003 9,and RPD=2.53.This research findings provide technical support for estimating soybean yields in the dump of open-pit coal mine in the black soil region and offer data-driven insights for precision field management and reclamation effectiveness evaluation.

Abstract:Based on the concepts of systemic governance and sustainable development,this study addresses the complexity and specificity of ecosystems in abandoned open-pit mines.Taking the Zhenziyan Ming Area ecological restoration project,a typical limestone mining area in Chongqing,as the research object,it highlights the governance approach of"determining governance based on utilization".The study conducts systematic ecological restoration and comprehensive utilization research,constructing a"limestone mine model"centered on"graded management of geological hazards-landscape reconstruction-vegetation configuration oriented toward carbon sink-industrial integration planning".Through analyzing the current geological environment and key ecological issues of the Zhenziyan Mining Area,combined with the surrounding environment and site characteristics,the study innovatively proposes suitable directions for subsequent utilization and functional zoning of the mining area.It carries out ecological restoration and comprehensive utilization design tailored to local conditions and conducts a systematic effectiveness evaluation.The results show that the restoration effect index of the Zhenziyan Mining Area in Nanchuan District is 0.852,with an annual carbon sequestration of 285 t CO2 in the restored mining area and a 12%increase in soil organic carbon storage compared to before restoration.Based on this,the study systematically summarizes and concludes innovative experiences in ecological restoration and comprehensive utilization of mining areas,providing a model reference for ecological restoration and regional low-carbon development in China's mining areas.

Abstract:Green mine construction is a crucial initiative for realizing the low-carbon transformation and high-quality development of China's mining industry.Based on data from 31 provinces,this work applies the fuzzy-set Qualitative Comparative Analysis(fsQCA)method to systematically explore the complex causal mechanisms and multiple driving paths of green mine construction outcomes from the multidimensional perspectives of resource endowment,environmental constraints,economic foundation,policy support,and technological capacity.The results show that:(1)A single condition is not a necessary factor in promoting green mine construction.The green transition demonstrates typical"concurrent causality"characteristics.(2)In practice,multiple equivalent paths coexist to achieve high-level green mine construction,with the main types being"policy-investment driven","technology-ecology synergistic",and"resource-economy led".(3)Two types of configuration paths affecting green mine construction outcomes are identified,with combinations such as resource dependence,fiscal constraints,and technological shortcomings exerting restrictive effects on the green transition.This study reveals the spatial heterogeneity and diversified pathways of green mine construction in China,and provides a theoretical basis for adopting locally tailored,category-based,and differentiated construction strategies to advance the green transformation of the mining industry.

Abstract:The increasing number of closed or abandoned mines(COAMs)is likely to trigger problems such as resource idleness,ecological damage,economic development imbalance,and social contradictions.Against the backdrop of the"dual carbon"goal,the development and utilization of these mines are extremely urgent.Therefore,a study on the evaluation index system for the classified and graded development and utilization of resources in COAMs has been carried out.Based on the concept of coordinated development and utilization of"energy utilization,resource utilization,and functional utilization",the analytic hierarchy process is applied.A classified and graded evaluation index system for resources in COAMs has been constructed,which includes three dimensions:resource attributes,environmental constraints,and economic feasibility.The development and utilization of resources in COAMs are divided into"five categories"and"four levels".Taking the actual resource conditions of Longdong Coal Mine of Shanghai Datun Energy Co.,Ltd.as an example,the Delphi method is used to determine the weight of each indicator.Corresponding development and utilization suggestions are put forward.The guiding value of this evaluation index system in resource potential assessment and development path optimization has been verified.The results show that Longdong Coal Mine is suitable for Type Ⅲ functional utilization and belongs to the general development at Level Ⅱ.

Abstract:The ecological environment of coal mining areas in western China is highly fragile.Ground fissures induced by coal extraction subsidence exacerbate soil erosion and degradation.Microbial-based land reclamation has become a research hotspot in ecological restoration of mining areas.This study focuses on elucidating the functional mechanisms by which algal crusts influence soil physicochemical properties and water transport processes in fissured areas,aiming to reveal the key ecological roles in mitigating soil structure degradation and water-nutrient loss.Algal-crusted and bare soils in fissure areas were selected as study objects.Through soil structural analysis,water infiltration and evaporation tests,as well as nutrient content determination,the ecological effects of algal crusts under fissure disturbance were systematically assessed to provide a theoretical basis for artificial algal crust applications in ecological restoration.The results showed that with the increase in fissure scale,soil exhibit higher sand content,reduced silt and clay fractions,decreased surface soil moisture,accelerated infiltration and evaporation rates,and significantly lower nutrient levels.In non-fissured areas,algal crusts improved soil quality significantly,increasing organic carbon,total nitrogen,total phosphorus,and surface moisture content by 91.13%,27.48%,23.46%,and 38.77%,respectively,while reducing infiltration rate by 42.9%.In fissure areas,algal crusts alleviate water and nutrient loss effectively,increasing surface soil moisture from 18.36%to 42.85%.Algal crusts exhibit significant functions in water retention and nutrient accumulation,and hold promissing prospects for application in ecological restoration of coal mining subsidence areas.

Abstract:Large-scale shale gas development in ecologically sensitive areas is confronted with severe environmental challenges such as water resource consumption,land occupation,and solid waste management.Taking the normal-pressure shale gas field in Nanchuan,Southeastern Sichuan as the engineering context,a management-technology dual-driven green development system has been established,covering the entire process of source reduction,process control,resource recycling,and terminal treatment.Engineering practice demonstrated that the system achieved 100%resource utilization of both oil-based and water-based drilling cuttings,as well as 100%compliance treatment and reuse of produced water;it has cumulatively reduced land acquisition by 13.33 hectares,saved 95.1×103 tons of standard coal,cut CO2 emissions by 46.6×103 tons,and significantly lowered operational noise and annular pressure buildup rates.The results indicate that this system effectively mitigates ecological disturbances and pollution emissions during shale gas development,offering a replicable and scalable solution for green development in ecologically sensitive regions.It provides an important reference for advancing the clean transition of unconventional natural gas in China.

Abstract:To understand the spatiotemporal distribution patterns of surface deformation in the Haizhou Open-Pit Mine,China's first L-band differential interferometric SAR satellite constellation,LuTan-1(LT-1),was utilized.A total of 39 ascending and descending LT-1 SAR images from May 2023 to January 2025 were collected.Techniques including D-InSAR and PSInSAR were employed to analyze the spatiotemporal characteristics of surface deformation in the mining area,with optical remote sensing images used to validate the reliability of the results.The findings reveal that the southern slope of the Haizhou Open-Pit Mine exhibits the most significant subsidence,while unstable areas also exist on the eastern and western slopes as well as the central region,though with lesser deformation magnitudes compared to the southern slope.The mining area covers approximately 6.300 km2,of which the region with a deformation rate exceeding 0.50 m/a accounts for an area of 0.146 km2,representing about 2.3%of the total area.The area with deformation ranging between 0.20 m/a and 0.50 m/a is 0.648 km2,constituting approximately 10.3%of the total area.The spatial extent of deformation detected by LT-1 SAR data is generally consistent between ascending and descending orbits,though notable differences exist in the magnitude of deformation rates,with the ascending orbit generally exhibiting lower deformation rates compared to the descending orbit,indicating its lower sensitivity.The descending orbit data provide better observational angles forthe southern and eastern slopes,while the ascending orbit data are more suitable for the western slope.By integrating data from both ascending and descending orbits,the spatial distribution and temporal evolution of deformation in the mining area can be comprehensively reconstructed.

Abstract:In order to explore the influence of area affected by fault clamping on the overburden strata migration under mining conditions,based on the mining geological conditions of the 6305 fully mechanized mining face of Xinjulong Coal Mine,the overburden strata structure,displacement characteristics and fault activation characteristics before,during and after mining from the face to the area affected by fault clamping were analyzed by using indoor simulation method.The research results show that before the 6305 fully mechanized mining face passes through the F311 and XF2 faults,the arch structure was formed after overlying rock failure.When mining to F311 and XF2 faults,due to the fault cutting effect,the"arch"overburden structure showed peculiarity and the development of the"arch"overburden structure was discontinuous.After mining fault F311,the arch foot of the"arch"overlying rock structure fell on the low rock layer of the footwall,and the stress at the arch foot increases,resulting in the overall cutting of the low rock layer.After mining fault F311,a new strange"arch"overlying rock structure was formed between the working face and XF2 fault.When the working face 6305 started mining,the F311 fault first showed activation characteristics.When the working face was pushed to the F311 fault,the maximum subsidence displacement of the lower strata was 9.0 m,while the upper strata had no subsidence displacement.In this case,the F311 fault was activated significantly at the lower strata while the upper strata did not activate.When the working face was pushed to the XF2 fault,the maximum subsidence displacement of the lower strata was 7.8 m,while the upper strata had no subsidence displacement.In this case,the XF2 fault was obviously activated at the lower strata,while the upper strata was not activated.

Abstract:The interaction between regenerated rock mass and its support structure is complex.To clarify how bolted structures support regenerated rock mass,we investigated the effect of various support parameters on its bearing capacity.Using sand 3D printing technology,we designed and fabricated bolted specimens with different bolt densities and arrangements.We analyzed the reinforcing effects and relationships between support parameters,and examined the bearing mechanism of bolted structures through theoretical analysis.Results show that increasing the number of bolts initially improves the peak stress and elastic modulus of the specimens,but excessive bolting can reduce these benefits.Lateral increases in bolt numbers gradually weaken reinforcement.Higher support density helps limit crack development and elastic strain energy release during loading,leading to reduced acoustic emission and lower strain concentration,which suppresses crack initiation and growth.We established a safety factor criterion for the stability of roof and rib bolting structures of regerated rock mass,confirming that bolt density significantly affects the properties of the bolted body.By coordinating support parameters with those of the regenerated rock mass and leveraging their characteristics,more stable control and optimized bolting design can be achieved.

Abstract:In order to clarify the water filling sources of the mine water in Bulianta Coal Mine and the replenishment ratios of each water source,so as to ensure the rational allocation and safe management of the mine water resources,hydrogen-oxygen stable isotope tracer analysis was carried out in this study.A total of 28 water samples were collected for the study,covering surface water,Quaternary diving,water from the Zhidan Group,water from the Yan'an Formation and water from the goaf.The δ18O and δ2H values were determined by wavelength scanning cavity ring-down spectroscopy(WS-CRDS)technology,and the contribution ratios of each water source to mine water were calculated by applying the IsoSource model.The results show that the aquifer water of the Yan'an Formation is the main water source of the mine,accounting for 50.4%.The water in the goaf and the quaternary diving accounted for 25.3%and 21.0%respectively.The water of the Zhidan Group accounts for 2.5%,while the contribution of surface water is only 0.7%.The root mean square error(RMSE)calculated by the model is 0.069,indicating a good fitting effect and high reliability of the results.Based on the results of isotope analysis,this paper proposes an optimization strategy for mine water resources management,covering measures such as water source monitoring and assessment,rational allocation,water quality treatment and pollution control,providing a strong scientific basis for the efficient utilization and protection of mine water resources.

Abstract:The Sichuan Basin,a major oil and gas producing region in China,has accumulated extensive geological,seismic,and drilling data,providing a strong foundation for regional geothermal energy development.Despite this informational advantage,geothermal resources within existing oil and gas wells remain largely underutilized.Focusing on the Moxi area,identified as having significant geothermal anomalies,this study prioritizes the deeper,higher-temperature,and thicker Longwangmiao Formation reservoir,as reservoir temperature and depth are crucial for the economic viability of geothermal projects.A three-dimensional geological model of the reservoir was constructed,and the one-dimensional steady-state heat conduction equation was used to estimate the internal temperature distribution.Results show that the Longwangmiao Formation reservoir in the Moxi area has temperatures ranging from 104℃to 154℃.The total geothermal resource is estimated at 2.04×1010 J(equivalent to 696 million tons of standard coal),with a recoverable portion of 3.06×109 J(equivalent to 104 million tons of standard coal).Based on these findings,a development strategy is proposed:prioritize direct use or ORC power generation,utilize power generation tailwater for drying applications,and implement cascade utilization of geothermal energy.Future research should explore the integration of geothermal with other renewable energy sources to support large-scale geothermal power generation and provide technical reserves for sustainable energy development.

Abstract:As deep coal mining expands,water damage resulting from roof separation during the overlapping extraction of multiple coal seams has become a significant hazard and a key research focus.This study examines the West No.1 Mining Area of the Hongyang Coalfield to systematically analyze the spatial and temporal evolution and aperture variation of overlying strata separation under multi-seam mining conditions,by using similar materials,3DEC numerical simulation and other means.The results indicate that the development of bed separation is strongly influenced by the rupture of key strata,interactions within the mining-induced stress field,and the sequence of seam extraction.High-level separation between coal seams 7 to 12 can reach a maximum aperture of 3.5 meters under combined field effects,while immediate roof separation above coal seam 3 is limited to 0.6 meters due to key stratum interaction.Based on these findings,a predictive model for bed separation aperture was developed,incorporating key stratum theory and the effects of rock fragmentation and bulking.Field measurements from working face 301 show that model predictions deviate by less than 15%.

Abstract:To address the challenges of traditional uniaxial compressive strength(UCS)testing for roof rock formations,we proposed an in-situ method that estimated UCS using drilling parameters.Focusing on the extrusion and crushing behavior of a PDC anchor bit in plastic soft rock,we derived a relationship between cutting force and UCS based on the mechanics of rock breaking by the cutting edge.An in-situ testing method for rock strength was proposed.Laboratory experiments were conducted on mortar samples of varying strengths using a custom-built drilling test device with constant drilling pressure,measuring drilling rate,torque,and rotation speed.Results indicate that torque is positively correlated with rock strength,cutting edge width,and cutting thickness.To account for differences between the dynamic drilling process and static analysis,an adjustment factor was introduced;this factor remains constant for the same drilling machine.The average relative error between UCS values calculated by the theoretical model and those measured experimentally is less than 13%,demonstrating the model's validity.

Abstract:Accurate gas concentration prediction is essential for preventing and controlling gas-related disasters in coal mines.However,existing methods often lack accuracy,generalizability,and rely solely on point predictions.To address these challenges,we propose an interval prediction model that combines a gated recurrent unit(GRU)network with nonparametric kernel density estimation(NKDE).The GRU network first generates point predictions of gas concentration,from which we create a dataset of prediction errors.We then use kernel density estimation,optimizing the bandwidth based on mean squared error,to model the distribution of these errors.By integrating the GRU predictions with the estimated error distribution,we construct prediction intervals at various confidence levels.We validate our approach using historical data from two different coal mine sites.Results show that the GRU model outperforms support vector machines(SVM),backpropagation neural networks(BP),and ARIMA models in prediction accuracy.Additionally,the optimized kernel density estimation provides a more accurate representation of prediction errors than both the Gaussian model and kernel density estimates with arbitrary bandwidths,resulting in more reliable prediction intervals.This method offers a practical tool to enhance safety management in coal mines.

Abstract:Liuhuanggou coal mine is one of the typical coal mines with repeated mining of huge thick multi-seam coal mine.In the early stage of coal mining,the shallow ground subsidence is relatively small,and there is a lack of effective subsidence monitoring data,making it impossible to verify whether subsequent mining will cause abnormal ground subsidence.With the background of repeated mining conditions of multiple coal seams in Liuhuanggou Coal Mine,combined with the mining conditions of the mine,we carried out the research on the characteristics of repeated mining land subsidence by using two kinds of monitoring means,namely,the conventional manual monitoring of ground measuring line and the LIDAR three-dimensional monitoring of the ground surface subsidence.The measured results show that the period from August 1,2022 to December 28,2022 is the main period of land subsidence.The mining of the(9-15)08 working face caused a large amount of land subsidence,with the maximum subsidence value tending towards the upper part of the(4-5)04 working face in the deep part.The risk of a sudden large-scale land subsidence in the later stage is extremely low.It is predicted that the maximum land subsidence will be 4.6 m before the mining of(9-15)08 working face,and after the mining is completed and stabilized,The maximum surface subsidence is 16.9 m.Land subsidence measurements provide a basis for revealing the laws of land subsidence and abnormal collapse under repeated mining conditions in the Liuhuanggou Coal Mine,and for in-depth study of the damage characteristics of the overburden rock of the comprehensive mining in the Changji Mining Area in Xinjiang,and the comprehensive technical methods adopted provide important technical support for ecological environmental protection in the mining area.

Abstract:In order to clarify the coal-water mixture in the hydraulic slotting slag discharge process in the drilling hole movement rules and drilling cinder bearing capacity,to avoid the occurrence of plugging holes,holding drilling and other phenomena due to the slit falling coal is greater than the drilling cinder bearing capacity,first of all,we need to grasp the morphology characteristics of the coal slag particles.The OCCHIO ZEPHYRESR2 dynamic image particle size and particle shape instrument was used to test the particle size and particle shape of the coal slag particles in the hydraulic slotting of four working conditions in the underground coal mine.The particle size characteristics were characterized by the Feret diameter minimum,and the particle shape characteristics were characterized by the circularity and the irregularity indexes.The results show that:in terms of the number of particles,the particle size of hydraulic slotting cinder is mainly distributed in the range of 100 μm to 350 μm,and in terms of the volume of particles,the particle size of the cinder is mainly distributed in the range of 500 μm to 4 000 μm.The circularity of cinder particles is mainly distributed in the range of 0.6 to 0.8,and the irregularity are mainly distributed in the range of 0.45 to 0.65.Hard cinder particle size is larger than soft coal,and cinder particle size is larger in the first 5 min than in the last 5 min of a single slit,which provides basic parameters for the movement law of coal-water in the borehole,and it has important reference and significance for the adjustment and optimization of the relevant parameters of hydraulic slotting.

Abstract:The 13-1 coal seam in Zhujidong Coal Mine exhibits high gas pressure and high gas content,belonging to the outburst coal seam.In order to eliminate the danger of outburst and ensure the safe and efficient mining of the coal seam,this study proposes employing surface well staged hydraulic fracturing technology to induce fractures in the coal seam.This process involves perforation and hydraulic fracturing along the wellbore trajectory to release pressure and increase permeability in each coal and rock layer.Following the strategy of segmented and clustered optimization and adopting different pumping strategies for each fracturing section,the principle of"large volume,large particle size,and high sand concentration"was utilized to regulate fluid volume and improve sand support effectiveness in each fracturing section.The actual injection of fracturing fluid and the amount of sand added were significantly higher than the designed parameters.Moreover,the four-dimensional image monitoring of fracturing fractures by intensive array energy scanning revealed that the total volume of hydraulic fracturing fractures in each section could reach 1 061.93×104 m3,and the daily gas yield during the stable gas production stage could exceed 2 500 m3.These findings demonstrate that surface well staged hydraulic fracturing technology is highly applicable for increasing permeability within the 13-1 coal seam by promoting intersection and penetration of fracture zones.Better cracking and permeability increase effect and gas drainage efficiency could provide safety guarantee for the safety of coal seam mining.

Abstract:In order to solve the problem of reduced measurement accuracy caused by zero drift in the online monitoring system for flue gas particles concentration,a zero point automatic calibration system for monitoring the mass concentration of flue gas particles based on laser scattering method was designed.Combining the probability theory in statistics,the influence process of zero drift on measurement accuracy was analyzed,and the system performance was verified through laboratory and on-site experiments.The test results show that the lower the mass concentration of particles,the greater the measurement error caused by zero drift.When the emission concentration of flue gas particles is less than 10 mg/m3,zero drift becomes the main source of error.Zero drift exhibits the characteristics of fluctuating up and down,with a maximum drift value of 2.02 times the initial value.After adopting the automatic zero-point calibration technology,the 95%measurement relative error of the flue gas particulate matter mass concentration real-time monitoring system was less than 6.3%in field comparison tests.

Abstract:To prevent personnel casualties and accident losses in coal mine production,a risk analysis method based on functional resonance analysis model(FRAM)and complex network(CN)was proposed.Firstly,the characteristics of coal mines were analyzed based on the investigation reports of 96 major coal mine accidents in recent years,and the causes of the sorted accidents were linked to the coal mining process to establish a FRAM model for coal mining production with 14 functional modules.Then,the coal mining production complex network model was constructed based on the FRAM model.Finally,based on the CN theory,the structural features of the coal mining production network were analyzed from the perspectives of nodes and links using node centrality and co-occurrence rate,and the risk evolution path from production start to accident occurrence was identified.Based on the analysis results,preventive measures for coal mine production accidents were proposed.The research results are of great significance for preventing coal mine production accidents and improving coal mine production safety levels.

Abstract:The"finger movement and dictation"safety confirmation can effectively reduce the risk of operational errors in the production process of coal mines.In order to solve the problem of lack of effective supervision in the implementation of traditional methods,a set of"finger movement and dictation"safety confirmation system in coal mine is designed based on deep learning technology.To judge whether the standardized operation is achieved by testing the cooperation of body and language,and to supervise,standardize and implement the implementation of the"finger movement and dictation"safety confirmation method at the technical level.Firstly,Whisper speech model is used to identify"dictation",and OpenPose is used to estimate human posture.Then,in order to improve the detection accuracy,an enhanced Transformer is proposed to improve the YOLOv8 model.The target detection of"finger movement"is carried out.Finally,the designed"finger movement and dictation"confirmation system is applied to two typical scenarios,namely checking whether personal protective equipment is complete and worn properly,and checking the key instrument equipment and operation conditions at the workplace.The system is tested on datasets constructed in the two scenarios,and the detection accuracy is 93.86%and 86.24%respectively,which proves the effectiveness of the system.