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Table of Content

15 July 2026, Volume 58 Issue 7
Key technology of backfill-retained roadway during right-angle turn of a deep L-shaped stope#br#
2026, 58(7):  1-9.  doi:10.11799/ce202607001
Abstract ( 107 )   PDF(mobile) (2578KB) ( 43 )  
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To avoid the pre-excavation of retreat roadway and the setting of protective coal pillars in deep L-shaped stopes, this study on the backfilling-roadway retention control technology for the retreat roadway is of great significance. It is crucial for significantly improving the recovery rate of coal resources and ensuring the safe and efficient mining of deep irregular working faces. In this paper, the theory of continuous curved beams was applied to analyze the relationship between the backfilling rate, the burial depth and the deformation curvature of the roof overburden for the surrounding rock of the retreat roadway. And the backfilling strength calculation method of the surrounding rock of the retreat roadway was given. The ratio control method for backfilling gangue and modified backfilling materials is proposed. A long-distance transportation control system for backfilling gangue and modified slurry, both above and below ground, was built on site. An integrated surrounding rock control technology was developed for the relocation of the inner section of the L-shaped stope, combining real-time support, backfilled and roadway-side support. Field applications show that the proportion control of backfill gangue and modified slurry has achieved long-distance, rapid, and quantitatively controlled transportation of filling materials. With the maximum deformation of the surrounding rock in the retained roadway section measuring only 99 mm. During the directional transition phase of the deep L-shaped stope, the strength of the backfill body and the stability of the surrounding rock of the retreat roadway has been significantly enhanced.
Research on Operational Modes and Development-Transportation System Layout of Bucket Wheel Continuous Coal Mining Process
2026, 58(7):  10-17.  doi:10.11799/ce202607002
Abstract ( 55 )   PDF(mobile) (2012KB) ( 5 )  
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To address the issues of high costs and poor equipment coordination in the semi-continuous process of open-pit coal mines, this study optimizes the bucket wheel continuous coal mining technology. First, the capacity of bucket wheel excavators and supporting equipment was calculated and selected based on parameters such as minable coal reserves. Second, the operational modes and layout of the pioneering transportation system for the continuous process were investigated, revealing the coupling relationship between bucket wheel steps and lower-level operations. Subsequently, a coal seam optimization model for the continuous mining process was developed, and the total benefits of applying the process to each coal seam were quantified. Finally, a phased implementation plan for deploying the continuous mining process was proposed. Validated through the case study of Hongshaquan No. 1 Open-pit Coal Mine, the results demonstrate: ① After optimization, the annual cost savings for a single deployment in the B4 coal seam reached 64.669 million yuan, while the combined application in B2’+B3+B4 coal seams increased savings to 178.4 million yuan/year, with unit costs reduced by 23%–35%; ② By designing “three-mining-one-relocation” and “two-mining-one-relocation” cyclic operation modes, combined with a graded relocation strategy for end-slope belt conveyors, the annual effective operational time increased to 4,842 hours, reducing equipment idle time by 21% compared to the original process. These findings highlight significant optimization outcomes and provide a theoretical framework for achieving “safety-economy-efficiency” synergy in continuous mining processes for open-pit coal mines in high-latitude regions.
Unattended management system for belt conveyors based on multi-sensor perception#br#
2026, 58(7):  18-24.  doi:10.11799/ce202607003
Abstract ( 53 )   PDF(mobile) (3732KB) ( 14 )  
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Abstract:Efficiency, intelligence, and safety are important aspects of the sustainable development of smart mining in the future. This paper proposes a smart mining technology system based on a collaborative framework of "equipment perception - raw data - transmission - platform," constructing a complete closed-loop framework of intelligent mining that encompasses equipment perception, data processing, online monitoring, fault diagnosis, and intelligent decision-making. The equipment perception layer acquires heterogeneous data through multiple sensors; the raw data layer processes and fuses compressed data using a network model; the transmission layer relies on technologies such as industrial Ethernet and 5G for real-time data transmission and remote monitoring; and the platform layer achieves fault early warning and intelligent decision-making through closed-loop networks, algorithms, and expert systems. Based on this framework, this paper elaborates on its components, principles, and functions, enabling equipment monitoring and protection under complex working conditions, ensuring the safe and efficient operation of transportation systems, enhancing the intelligence level of coal mines, and reducing the occurrence and losses of safety accidents.
Discussion on permissible vibration standards for production operation areas in coal industry buildings#br# #br#
2026, 58(7):  25-29.  doi:10.11799/ce202607004
Abstract ( 30 )   PDF(mobile) (1109KB) ( 5 )  
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To solve the problem of inconsistent allowable vibration standards in the production operation area of the coal industry,this article systematically analyzes the vibration characteristics of the main vibration sources in coal industry buildings,and uses the 1/3 octave band analysis method and vibration weighting analysis method,combined with parameters such as vibration intensity、frequency、direction and exposure time,to construct a graded vibration control evaluation standard with exposure limit,fatigue efficiency reduction limit, and comfort reduction limit as the core.The research results indicate that using the allowable vibration weighted acceleration level as the vibration control standard is conservative and more conducive to labor protection.
Energy-saving strategy of exterior wall colors for north-south oriented gallery apartment buildings in the Ordos mining area#br#
2026, 58(7):  30-35.  doi:10.11799/ce202607005
Abstract ( 32 )   PDF(mobile) (1516KB) ( 5 )  
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Abstract This study focuses on the south-north oriented corridor-type staff dormitory in the Ordos mining area, aiming to quantitatively analyze the impact of light-colored, dark-colored, and directional color real stone paint exterior finishes on building energy conservation and carbon reduction in the severe cold zone C. Based on the actual building parameters (6-story frame structure, shape coefficient 0.1659, window-wall ratio 0.28-0.32 for different orientations), the research compares the differences in heating and cooling energy consumption of different exterior wall colors through energy consumption simulation, considering seasonal (spring, summer, autumn, winter) and annual cycles.To verify the accuracy of the model, the simulation results were cross-compared with the operational data of similar buildings and the energy consumption design indicators for Severe Cold Region C?1?1??. Meanwhile, a sensitivity analysis was performed on solar radiation intensity and outdoor temperature fluctuations to clarify the energy-saving stability of the color schemes?1??1??. The results show that dark colors can reduce heating energy consumption in winter (black saves 15.19% compared to white), while light colors significantly reduce cooling energy consumption in summer (white saves 27.48% compared to black). For the annual comprehensive performance, medium gray exterior walls achieve the optimal energy-saving effect, with a 1.95% reduction compared to the white benchmark, corresponding to a carbon reduction of 4551 kgCO?. The sensitivity analysis indicates that dark colors are more sensitive to solar radiation fluctuations, light colors show more prominent energy-saving advantages as outdoor temperature rises, and the orientation-based scheme presents the best stability under climatic parameter fluctuations. This study provides quantitative basis and practical reference for energy-saving and carbon-reduction strategies of exterior wall colors in mining area buildings in severe cold zone C.
Study on a rock cross-cut coal uncovering outburst prevention technology based on blasting-injection weakening and grouting reinforcement#br#
2026, 58(7):  36-44.  doi:10.11799/ce202607006
Abstract ( 42 )   PDF (12216KB) ( 38 )   PDF(mobile) (12322KB) ( 7 )  
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To tackle the critical challenges of difficult stress relief, unclear energy release laws, and high outburst prevention difficulty in deep cross-measure coal uncovering, this study identifies that the energy accumulation and chain failure of structural inclusions under high stress-gas pressure gradients are the core inducing factors for coal and gas outburst. A novel synergistic outburst prevention technology of blasting-injection weakening combined with grouting reinforcement is proposed. Specifically, one blasting-injection hole and twelve control holes are arranged ahead of the heading face. Through a sequential implementation of pressure-relief blasting for prefabricating fractures, water injection for fracture expansion and pressure reduction, gas extraction, and grouting reinforcement, a "strong-weak-strong" structural zonal layer is formed. A numerical model was established via FLAC3D to simulate the proposed technology. The simulation results show that with this method, a stress relief zone of approximately 10 m is formed on both sides of the roadway within the coal seam, with the average stress reduced to 2.5 MPa, indicating a significant mitigation of stress concentration. During the coal uncovering process, the elastic energy release in the control zone is reduced by two orders of magnitude compared with coal seams treated by conventional methods; the maximum displacement of the roadway roof and floor is decreased by 60%, and the scope of the plastic failure zone is narrowed, which verifies the remarkable outburst prevention effect of the technology.Furthermore, parameter optimization confirms that "Strength Grade 4" is the optimal grouting parameter. It achieves the optimal balance among pressure relief, deformation control and energy regulation, and avoids the attenuation of marginal benefits caused by excessive reinforcement.
Study on a rock cross-cut coal uncovering outburst prevention technology based on blasting-injection weakening and grouting reinforcement#br#
2026, 58(7):  45-54.  doi:10.11799/ce202607007
Abstract ( 42 )   PDF(mobile) (7215KB) ( 25 )  
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Aiming at the practical engineering problems of strong mining stress and difficult control of surrounding rock in 3206 island working face roadway of Wangpo Coal Industry during mining, the engineering geological analysis, overburden structure theory, field test, numerical simulation and field industrial test are comprehensively used. Based on the analysis of the movement law of the overlying rock structure of the working face, it is revealed that the core mechanism of the deformation of the surrounding rock is the coupling effect of the cantilever effect of the high hard roof and the stress transfer of the lateral goaf. Through field test, the key horizon of directional long horizontal hole hydraulic fracturing with the target of sandstone interaction layer 40 m above the section coal pillar is determined. The numerical simulation results show that after the implementation of regional fracturing, the peak stress of the coal pillar side of the roadway is significantly reduced from 38 MPa to 20 MPa ; the roof subsidence, floor heave and two-side convergence decreased by 46.7 %, 61.0 % and 49.8 % -52.1 %, respectively. The area of plastic zone of surrounding rock is reduced from 116.3 m2 to 69 m2, which is reduced by 40.7 %. The vertical average stress of the key layer decreased from 20.8 MPa to 16.9 MPa, and the stress distribution tended to be gentle. The field engineering application monitoring data verified the effectiveness of the technology : the average step distance of the periodic weighting of the working face was reduced from 17 m to 11.6 m, a decrease of 32.2 % ; the average dynamic load coefficient is reduced from 1.75 to 1.42. The average reduction of roof subsidence, floor heave and two-side convergence of roadway is 58.8 %, 47.9 % and 51.2 % respectively, and the maximum reduction of surrounding rock deformation rate is 87.36 %. The working resistance distribution of the bracket is significantly transferred to the low resistance range.The research shows that the stability of surrounding rock in the roadway of high stress island working face can be significantly improved by implementing directional hydraulic fracturing for high key strata to cut off the lateral stress transfer path.
Corrosion fatigue design and service life prediction of rock bolts in deep mine environments#br#
2026, 58(7):  55-65.  doi:10.11799/ce202607008
Abstract ( 44 )   PDF(mobile) (3369KB) ( 8 )  
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The support structures of deep mine tunnels are subjected to harsh service conditions such as high ground stress, strong corrosion, and frequent dynamic disturbances. Under long-term cyclic loading, the anchor rod body is susceptible to corrosion fatigue failure, leading to deformation and instability of the surrounding rock of the galleries. 1. Taking deep coal mine support anchor rods as the research object, analyzing the factors inducing corrosion fatigue of the rod body and the fatigue failure theory, revealing the mechanism of corrosion fatigue failure of the rod body; 2. Carrying out indoor accelerated corrosion tensile tests on rod materials, the results show that corrosion leads to a decrease in yield strength and ultimate strength. Combined with theoretical analysis, it is found that the decrease in yield strength and ultimate strength leads to a reduction in fatigue limit; 3. Based on the theory of finite fatigue life design of metals, introducing the influence factor of corrosion degradation strength, a calculation model for the corrosion fatigue life of anchor rods is proposed; 4. Based on the calculation model of anchor rod corrosion fatigue life, the factors influencing corrosion fatigue life are studied from three levels: corrosion degradation, energy release from strata movement, and rod material. The results show that corrosion degradation reduces service life and has a significant impact on low-cycle fatigue loads. An increase in energy release from strata movement and stress concentration factor decreases the corrosion fatigue life of anchor rods, while an increase in surface coefficient and dimension coefficient increases the corrosion fatigue life of anchor rods; 5. Taking Zhaolou coal mine as the engineering background, combined with microseismic data and indoor test results of anchor rod materials, corrosion fatigue life calculations are performed on four types of anchor rods: 335MPa, 400MPa, 500MPa and 600MPa. The results show that 335MPa and 400MPa anchor rods cannot meet service requirements, 600MPa anchor rods have excessively conservative service life, and 500MPa anchor rods can meet the requirements for corrosion fatigue durability.
Study on micro-pile reinforcement technology for soft rock roadway floors
2026, 58(7):  66-74.  doi:10.11799/ce202607009
Abstract ( 27 )   PDF(mobile) (6583KB) ( 8 )  
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Stability control in soft rock roadways remains a critical challenge restricting the development of many coal mines in China. To address the support difficulties in the New Shanghaimiao mining area, we used field investigation and numerical simulation to clarify the deformation characteristics of soft rock roadway surrounding rock and reveal the mechanism of large floor heave. A mechanical model and analytical method for the roadway floor were established using the limit equilibrium principle. We then proposed a new support design using floor micro-piles and optimized the support parameters. The results show that groundwater significantly weakens the floor strata, and when combined with high mining - induced stress, the surrounding rock undergoes progressive failure under a high stress-to-strength ratio. The self-bearing capacity decreases beyond the support capacity, leading to shear failure and large-scale floor heave. The proposed floor micro-pile support effectively reduces the unbalanced thrust in the floor and improves stability. The greater the unbalanced thrust, the larger the micro-pile forces and the required reinforcement area, both increasing linearly. Conversely, increasing the micropile diameter reduces the forces and required area in a power-law manner. These findings were validated by field industrial tests, providing theoretical and technical guidance for surrounding rock control in the Shanghaimiao mining area and other soft rock coal mines.

Mechanism of Rock Burst Inhibition Through Bed Separation Grouting and Its Engineering Application
2026, 58(7):  75-82.  doi:10.11799/ce202607010
Abstract ( 33 )   PDF(mobile) (5718KB) ( 34 )  
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To prevent and control rockburst disasters induced by the fracture of thick-hard key strata, the energy release mechanism was revealed based on the key stratum theory. Analysis indicates that the bending elastic energy released during key stratum fracture is proportional to the square of the rock stratum thickness and the 2.5th power of the tensile strength. Furthermore, the residual energy propagating to the roadways determines the rockburst risk. A technique utilizing overburden bed separation grouting to control the key stratum was proposed. By filling the mining-induced separation spaces, a compacted load-bearing zone is formed in the central goaf, reshaping the overburden stress field to inhibit key stratum fracture. Numerical simulation studies demonstrated that after grouting, the coal stress concentration coefficient decreased by an average of 10%, while the peak stress in the central goaf increased by 149%. Engineering practice showed that following grout filling, the proportion of high-energy microseismic events (≥103J) at the working face decreased from 16.98% to 3.72%, significantly reducing the rockburst risk.
Development and application of pressure relief technology by directional long borehole staged hydraulic fracturing in hard roofs#br#
2026, 58(7):  83-89.  doi:10.11799/ce202607011
Abstract ( 32 )   PDF(mobile) (6568KB) ( 12 )  
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This study addresses the long breaking span and difficult caving of the hard thick sandstone roof in the No. 3 coal seam of Sangshuping No. 2 Mine by developing and applying a directional long-hole segmented hydraulic fracturing technology for roof pressure relief. Based on hydraulic fracturing theory, mechanical criteria for fracture initiation and propagation are established, revealing the formation and evolution of a penetrating fracture network in the roof. Field application on the 3311 working face, combined with microseismic monitoring, roadway deformation monitoring, and ground pressure analysis, verifies the effectiveness of the technology. The results show that it forms a complex 3D fracture network, reduces roof strength and stress concentration, shortens the suspended roof span, stabilizes roof separation and roadway deformation, lowers support resistance, and weakens and shortens the influence of ground pressure, thereby improving mining safety.
Mechanism and effect analysis of underground directional longhole hydraulic fracturing for rockburst prevention
2026, 58(7):  90-96.  doi:10.11799/ce202607012
Abstract ( 24 )   PDF(mobile) (1620KB) ( 12 )  
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To address the difficulty of achieving large-scale pressure relief in high-position thick and hard roofs of rockburst-prone working faces, theoretical analysis and field monitoring methods were employed to investigate the mechanism of underground directional long-hole hydraulic fracturing for rockburst prevention and to evaluate its fracturing and control effects. The results indicate that: (1) The underground directional long-hole hydraulic fracturing technique injects fracturing fluid into thick and hard strata to generate fractures, thereby degrading the rock integrity and weakening its capacity to accumulate elastic energy. Meanwhile, the increased fracture density promotes the timely caving of the thick and hard roof in the goaf, which provides supporting effects on the overlying strata and effectively reduces both static and dynamic stresses in the surrounding coal and rock mass. (2) Analysis of borehole pressure, fracturing fluid flow curves, and water discharge during the fracturing process reveals the initiation and propagation of fractures, forming a fracture network and significantly impairing the integrity of the hard roof. (3) After implementing hydraulic fracturing, both the total energy release and frequency of microseismic events are substantially reduced, with a notable decrease in high-energy events. Additionally, the periodic weighting interval and dynamic load coefficient are lowered, while the working resistance during non-periodic weighting remains relatively stable.
Research On Ultra-High Pressure Water Jet Slotting and Pressure Relief Technolo-gy For Rockburst Coal Seam
2026, 58(7):  97-105.  doi:10.11799/ce202607013
Abstract ( 28 )   PDF(mobile) (7932KB) ( 3 )  
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The rockburst seriously affects the safety and production of coal mines. Based on the principle of ultra-high pressure water jet slotting coal seam pressure relief, the rockburst coal seam water jet slotting anti-rockburst technology is proposed. Firstly, the stress wave intensity on both sides of the slotting groove was analyzed, revealing the dynamic load blocking effect of water jet on the slotting groove inside the coal seam. The slotting groove can block the propagation path of dynamic load inside the coal layer, and the stress wave intensity is greatly reduced after entering the slotting groove, thereby reducing the damage of impact load to the mining space; the relationship between the settlement and supporting force of cut seam coal was studied. As the ultra-high pressure water jet cuts the coal and destroys its integrity, the pressure bearing capacity of cut seam coal decreases, thereby improving the stress environment of the coal seam and achieving unloading and load reduction of cut seam coal; The relationship between the width of the plastic zone of the slotting seam and the starting conditions of the impact ground pressure was analyzed. The slotting seam near the mining space can extend the width of the plastic zone of the surrounding rock of the roadway, and the water jet slotting seam has an increasing impact barrier effect on the coal body. Then, numerical simulation analysis was conducted on the stress distribution of the coal body in the coal seam slotting area of the coal mining face and section. It was found that the slotting groove formed by high-pressure jet slotting inside the coal seam can effectively alleviate the stress concentration state in the seam slotting area, and transfer the high stress area to the deep coal body. The rational process parameters for coal seam slotting were obtained from the perspective of stress relief, with a reasonable slotting drilling depth of 20m and a slotting drilling spacing of 3m. Through the on-site application of ultra-high pressure water jet slotting pressure relief and anti-rockburst technology in the fully mechanized top coal caving working face of Hujiahe Coal Mine, the average event energy decreased by 18% within a 100m mining mileage range, the microseismic energy per unit footage decreased by 37%, and the number of measures required for the evaluation of the working face ground sound trend method decreased by 56%. This indicates that ultra-high pressure hydraulic slotting technology can effectively reduce the risk of rock burst in mining working faces and provide more technical means for the management of rock burst disasters in coal mines.
Research on lightweight object detection technology for fully mechanized coal mining faces based on improved YOLOv8#br# #br#
2026, 58(7):  106-114.  doi:10.11799/ce202607014
Abstract ( 24 )   PDF(mobile) (6173KB) ( 9 )  
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Due to adverse factors such as coal dust interference, changes in illumination, equipment spatial position alterations and occlusions, as well as dynamic variations in the monitoring camera’s perspective, the automatic detection and recognition results of key target objects in mining face production scenes are prone to missed and false detections, especially for small target objects. This directly impacts the reliable application of intelligent video monitoring under work face production conditions. In order to improve the accuracy of automatic detection and recognition of key target objects, particularly small target objects, under actual production conditions and to enhance the effect of intelligent monitoring, this paper proposes an improved lightweight target object automatic detection algorithm model for mining faces based on YOLOv8. In the network of the algorithm model, the C2f module is first replaced with the C2f-Faster convolution module. Through structural lightweighting and computational optimization, model complexity is reduced and redundant computations as well as the number of parameters are minimized. Secondly, a SimAM attention mechanism is introduced, which uses the energy scale between features as a factor for assigning feature attention weights. This enhances the model's feature representation ability, achieving high detection accuracy for multi-scale objects, especially for small target objects, with minimal computational overhead. Furthermore, to address the degradation of the CIoU loss term during model training, which fails to reflect the true state of width and height regression, a new loss function called NIoU is proposed. This loss function enhances the sensitivity of the gradient during backpropagation to errors in the width-to-height ratio of the predicted target object boxes, thereby improving detection precision and recall. Experimental validation using actual data from multiple domestic mining face scenarios shows that, compared to the YOLOv8 model, the proposed algorithm model achieves a 39.13% reduction in the number of parameters, a 39.90% decrease in computational load, a 1.8% improvement in detection accuracy of target objects, and a 24% increase in inference speed. Finally, the proposed target detection algorithm model is applied to intelligent video monitoring of mining faces, demonstrating satisfactory performance that meets the real-time and reliability requirements for engineering applications.
TextRank-Protégé-based knowledge modeling for rockburst and its engineering application#br#
2026, 58(7):  126-134.  doi:10.11799/ce202607016
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In order to achieve intelligent analysis and treatment of rock bursts in coal mines, as well as facilitate the sharing and reuse of knowledge related to this phenomenon, this paper proposes the construction of a knowledge base for predicting and preventing mine rock bursts based on ontology. Firstly, following an analysis of the requirements for ontology construction and a comparison of existing methods, we employed a seven-step approach to develop the ontology specific to rock bursts. Utilizing the Textrank algorithm, we extracted significant entities pertinent to the prediction and prevention of rock bursts from relevant literature as sources for conceptual terms. Subsequently, we analyzed the interrelationships among these types before constructing a comprehensive knowledge base on rock bursts in coal mining using ProTéGé software. The rules were formulated based on a composite index method alongside SWRL language. Taking a coal mine as an illustrative example, we deduced the risk level associated with rock bursts according to established rules and proposed appropriate preventive measures. This paper advocates for establishing a knowledge base aimed at enhancing predictions and preventative strategies regarding rock bursts through ontological frameworks. Furthermore, it aims to enable rule-based reasoning concerning such predictions while assisting in analyzing causes behind impact accidents and informing decision-making processes related to disaster prevention and control measures—ultimately improving safety intelligence within coal mining operations.
Research and Application of Visual Intelligence Monitoring for Straightness in Fully Mechanized Coal Face
2026, 58(7):  135-144.  doi:10.11799/ce202607017
Abstract ( 18 )   PDF(mobile) (13444KB) ( 3 )  
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Affected by factors such as changes in the coal seam and geological conditions, fluctuations in pump station pressure, and asynchronous actions of the electro-hydraulic control system, the working face often fails to effectively maintain a relatively straight state under production conditions, severely restricting the safe and efficient intelligent unmanned production of the working face. However, the working face straightness detection method based on the high-precision inertial navigation system has high system complexity, high cost, and large maintenance costs, making it difficult to ensure reliable daily engineering applications. In response to the above problems, a systematic study on visual monitoring of the linearity of the working face has been carried out.This method first uses the lightweight improved YOLOv8 semantic segmentation model , which effectively reduces the number of model parameters while realizing the visual structured dynamic division of the working face scene, and accurately extracts the edge features of key target areas such as the base of the hydraulic support and the pushing stroke. Secondly, an optimized dual-parameter image distortion self-correction algorithm is designed. It fully considers the distortion information of key targets on the working face and can obtain the camera's distortion parameters without external calibration. This enables self-correction of distorted images and acquisition of the contour information of key targets on the corrected working face. Finally, a distance mapping model between the visual image pixel plane and the three-dimensional physical space is established to complete the visual estimation of the misalignment distance between adjacent hydraulic supports and the pushing stroke, and based on this, a visual estimation curve of the straightness variation is constructed to achieve intelligent monitoring of the straightness of the working face based on non-contact visual perception. Experimental test verification shows that the lightweight improved YOLOv8 semantic segmentation model achieves real-time dynamic division of visual structure with a 40% reduction in parameters. The average segmentation accuracy of each target area is higher than 95%, and the single-frame image processing time is reduced to 12.3 ms. In addition, the visual estimation errors of the misalignment distance between adjacent hydraulic supports and the pushing stroke are both less than 5 cm, meeting the application requirements of working face straightness intelligent monitoring.
Data transmission and storage for multi-source mine group data based on message queue#br#
2026, 58(7):  145-151.  doi:10.11799/ce202607018
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To address issues such as poor real-time performance in multi-source data transmission and the lack of breakpoint resume mechanisms in intelligent coal mining, this paper proposes a message queue-based distributed data collaborative transmission and storage scheme. By constructing a hybrid message queue architecture integrating Kafka and RabbitMQ, the scheme decouples data sending and receiving. It enhances concurrent transmission capability by combining an event-driven non-blocking I/O model with a multiplexing mechanism, and designs an intelligent breakpoint resume module to ensure data integrity.The overall architecture of the scheme consists of four layers: data sources, centralized control acquisition, data transmission, and data monitoring platform. Equipment data is uniformly collected through industrial protocols such as OPC UA, encrypted, and then distributed to Kafka topics. A ClickHouse distributed cluster is utilized to achieve PB-level data storage.Experimental data show that in applications across more than ten typical working faces, the scheme accumulatively collects over 1 billion data records in a single month without any loss, with data transmission delay reduced to the second level. Its efficiency is significantly improved compared with traditional methods, providing reliable technical support for data management and control of mine groups in coal mining enterprises.
5G-A Low-Altitude Intelligent Networking in Smart Coal Mining
2026, 58(7):  152-156.  doi:10.11799/ce202607019
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5G-Advanced (5G-A), featuring ten-fold data rates, millisecond latency and integrated sensing-and-communication capabilities, provides a new-generation technical foundation for low-altitude coal-mine scenarios. Systematically reviewing its core enhancements—higher peak data rates, increased connection density, improved latency and reliability, ISAC and native intelligence—the paper evaluates the technical feasibility and application effectiveness of UAV inspection, haul-truck supervision and emergency communications; results show a significant uplift in inspection efficiency and second-level safety alarms. The study also clarifies the positive impacts of 5G-A low-altitude intelligent networks on coal-industry safety, efficiency and low-carbon goals, and outlines an integrated air-ground-network ecosystem.
Evaluation of grouting modification effectiveness in roof aquifers based on GRA-TOPSIS-RSR with subjective-objective combined weighting#br# #br#
2026, 58(7):  157-166.  doi:10.11799/ce202607020
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In recent years, with the increasing depth of coal mining, the geological conditions faced by the grouting renovation are developing in a more complex direction, and the traditional method of evaluating the effect of grouting has been difficult to meet the needs of refined and quantitative engineering.Taking the grouting renovation project of S33 and S39 drilling holes in the four-five grey aquifer of the 11-coal roof of Qiuji coal mine in Shandong Province as the background, four influencing factors, such as final pressure of grouting, unit grouting volume, unit water absorption rate, and drilling fluid leakage, are selected as the evaluation indexes, and the weights of grouting evaluation indexes are determined by the entropy weighting method to improve the CRITIC method and combined with the AHP, and the grey correlation coefficients are introduced to improve the traditional TOPSIS method on the basis of which the traditional TOPSIS method is improved. On this basis, the grey correlation coefficient is introduced to improve the traditional TOPSIS method, and the GRA-TOPSIS-RSR grouting effect evaluation model is established. The evaluation results are compared and analysed with the water influx revealed by downhole drilling after grouting, and the evaluation results are basically consistent with the on-site verification, indicating that the GRA-TOPSIS-RSR evaluation model has good applicability. The method effectively improves the refinement of grouting effect evaluation and enriches the theoretical system of grouting effect evaluation to a certain extent.
Construction and application of a quantitative fracability evaluation model for thick and hard coal seam roofs#br#
2026, 58(7):  167-175.  doi:10.11799/ce202607021
Abstract ( 49 )   PDF(mobile) (2833KB) ( 5 )  
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Fracturing hard, thick roof strata is a critical step in coal mining. Currently in China, the control of hard, difficult-to-cave roofs primarily relies on blasting, supplemented by water injection softening. In recent years, advancements in hydraulic fracturing technology have provided robust technical support for fracturing coal seam roofs. The targeted selection of fracturing zones and intervals is key to improving fracturing efficiency. Therefore, this study, taking sandstone samples from the roof of the Caojiatan Coal Mine in Shaanxi as an example, established a quantitative fracability evaluation model for coal seam roofs through integrated methods including XRD, triaxial stress tests, and fracture toughness experiments. A standardized fracability evaluation index was constructed. The results indicate that the Fracability Index (FI) is most significantly influenced by rock brittleness, with lesser impacts from fracture toughness and natural fractures. When the Fracability Index FI > 0.53, the rock is most amenable to fracturing. This evaluation index enables the quantitative assessment of the fracability of target roof strata in coal seams, providing direct methodological support for selecting fracturing zones and intervals. The research findings can directly guide fracability evaluation of the roof and provide a basis for subsequent fracturing design.
Preparation, performance and mechanism of an RL-SPI bio-based foam dust suppressant#br#
2026, 58(7):  176-185.  doi:10.11799/ce202607022
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In order to reduce dust pollution on the road of open-pit coal mine transportation, RL-SPI foam dust suppressant was prepared by using natural biodegradable soybean protein isolate (SPI) and biotype surfactant rhamnose lipids (RL) as the main reagents, supplemented by sodium alginate(SA) and sodium chloride(NaCl) as additives. The experimental characterization results showed that the viscosity of the dust suppressant solution at a concentration of 0.5 % was 25.5 mPa·s. The compressive strength of the hardened layer formed on the surface of coal dust after spraying is 0.52 MPa. Under the condition of level 9 wind speed in the laboratory simulated roadway, the dust suppression efficiency was maintained at 94.23 %. In addition, Fourier transform infrared spectroscopy and scanning electron microscopy were used to analyze the mechanism of action of dust suppressants. Fourier infrared spectroscopy analysis showed that there was a chemical bonding between the dust suppressant and coal dust, and compared with water, the dust suppressant had a stronger hydrogen bonding effect with coal dust, which increased the hydrophilicity of coal dust and made it more wettable. Scanning electron microscopy further showed that there was a significant cementation effect between the treated coal dust particles. Therefore, the RL-SPI foam dust suppressant prepared in this study can effectively inhibit the diffusion of dust in coal mines and significantly reduce environmental pollution.
Thermodynamic-kinetic mechanism of coal-oxygen reactions and quantitative characterization of spontaneous combustion limit parameters#br#
2026, 58(7):  186-193.  doi:10.11799/ce202607023
Abstract ( 25 )   PDF(mobile) (1973KB) ( 1 )  
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In order to systematically evaluate the safety risks caused by coal spontaneous combustion, this study selected representative metamorphic coal samples (non-caking coal, weakly caking coal and lean coal) as the research object, and systematically studied their spontaneous combustion characteristics by using the programmed temperature experiment method. Through real-time monitoring of key parameters such as gas yield, oxygen consumption rate and exothermic intensity, combined with the analysis of apparent activation energy, the thermochemical evolution law of coal samples in the process of low temperature oxidation was deeply revealed. On this basis, the temperature dependence of the critical condition parameters of coal spontaneous combustion-the minimum floating coal thickness (hmin), lower limit oxygen volume fraction (Cmin) and the upper limit air leakage intensity (Qmax) was studied. The results show that the low metamorphic coal has higher oxygen consumption rate, and its oxidation process presents the typical characteristics of ' stable-slow increase-rapid increase-slow down '. Before 160 °C, the low metamorphic coal shows lower activation energy and stronger heat release capacity, showing higher spontaneous combustion tendency; the evolution of limit parameters shows that hmin and Cmin are positively correlated with the degree of coal metamorphism, while Qmax is opposite. This study provides a theoretical basis and data support for coal mine fire risk assessment and accurate early warning.
Preparation and performance influencing factors of leak sealing material based on silica fume - metakaolin - sodium silicate
2026, 58(7):  194-202.  doi:10.11799/ce202607024
Abstract ( 39 )   PDF(mobile) (7071KB) ( 2 )  
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Spray-based air-leakage sealing is a key technology for preventing coal spontaneous combustion in goafs. To overcome the high brittleness and poor durability of traditional cement-based materials, this study developed a novel inorganic sealing system incorporating silica fume, metakaolin, and sodium silicate. The effects of their contents on adhesion, compressive strength, permeability, and self-healing properties were investigated. The optimal performance was achieved with 6% silica fume, 10% metakaolin, and 3% sodium silicate, resulting in an adhesion of 22.63 g and a permeability of 0.48×10?2 mD after 25 days of curing. Self-healing tests revealed that alkali-activated silica fume and metakaolin form a C-S-H/N-A-S-H composite gel, which synergizes with expansive products like ettringite to seal cracks effectively. This work provides theoretical and technical support for designing durable sealing materials in deep mining.
Research on constitutive model for plastic flow of coal samples based on machine learning#br#
2026, 58(7):  203-209.  doi:10.11799/ce202607025
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To address the issue that coal pillars in the Guotun Coal Mine are prone to plastic flow after excavation-induced yielding, this study aims to reveal the plastic deformation laws and mechanical response characteristics of coal samples under post-peak cyclic loading conditions. Cyclic loading–unloading tests were conducted on coal samples under different confining pressures and loading paths to systematically analyze the axial stress–strain response characteristics after shear yielding. Based on the experimental data, a constitutive model describing the complex plastic behavior of coal samples was constructed by leveraging the excellent generalization capability of machine learning methods. Dynamic elastic modulus and damage evolution parameters were incorporated into the model to characterize the early-stage compaction and failure processes of coal samples observed in the tests. The results show that as the confining pressure increases, the peak strength of coal samples increases from 37.69 MPa to 68.36 MPa. Furthermore, the post-peak residual strength, plastic deformation capacity, and overall deformation resistance all exhibit an increasing trend. During the cyclic loading–unloading stages, the stress–strain curves display a pronounced hysteresis effect. The areas of the first to third hysteresis loops decrease successively, with cumulative attenuation rates ranging from 10.56% to 68.45%, indicating a gradual reduction in plastic dissipation energy. As the confining pressure increases from 2 MPa to 8 MPa, the total hysteresis loop area increases from 0.051 to 0.153, demonstrating a significant enhancement in plastic deformation capacity. Based on the experimental data, a machine learning constitutive model was constructed. The maximum relative error between model predictions and experimental results is 5.97%, validating the rationality of the model. The proposed model can efficiently solve the plastic behavior of coal samples and effectively describe their complex plastic mechanical characteristics, thereby providing a theoretical basis for the stability analysis of coal pillars under similar conditions.
Real-time dynamic disaster-avoidance route generation technology for mine fires based on multi-source data fusion#br#
2026, 58(7):  210-216.  doi:10.11799/ce202607026
Abstract ( 25 )   PDF(mobile) (2849KB) ( 3 )  
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In response to the strong suddenness of underground coal mine disasters and the difficulty of traditional static disaster avoidance path planning methods in adapting to dynamic disaster environments, this study proposes a real-time generation technology for dynamic disaster avoidance paths in coal mines based on multi-source data fusion, using the intelligent ventilation system of Sandaogou coal mine as the engineering background. By constructing a topology model of the mine ventilation network and integrating multi-source heterogeneous data such as gas concentration, wind speed, temperature, and personnel positioning information, a dynamically updated underground disaster evolution model is established; Based on the improved Dijkstra algorithm, the method of calculating the influence coefficient and equivalent length of roadway traffic is introduced to achieve dynamic optimization of disaster avoidance paths; The development of a real-time calculation module linked with the intelligent ventilation system ensures that the disaster avoidance path is dynamically updated as the disaster evolves. Engineering applications have shown that this technology can shorten the response time of path planning to within 30 seconds; In typical disaster scenarios such as gas exceeding limits, the accuracy of generating the optimal disaster avoidance path reached 98.7%, significantly improving the timeliness and reliability of emergency disaster avoidance in mines. This provides an innovative dynamic disaster avoidance solution for the construction of intelligent coal mines and has important engineering application value.

An accident severity prediction model integrating miners’ unsafe behaviors and accident types

2026, 58(7):  217-225.  doi:10.11799/ce202607027
Abstract ( 21 )   PDF(mobile) (2680KB) ( 3 )  
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Miners' unsafe behaviors are the core cause of coal mine accidents, and their risk consequences vary significantly across different work scenarios. A deeper understanding of the relationship between unsafe behaviors and accident types is crucial for achieving refined management of unsafe behaviors. Based on 2,697 coal mine accident reports collected nationwide in recent years, this study identified eight categories of typical unsafe behaviors and nine types of accidents, and constructed three predictive models: logistic regression, random forest, and enhanced random forest, to evaluate accident severity under the interactive effects of unsafe behaviors and accident types. The results show that the enhanced random forest model outperforms the others across five evaluation metrics, including accuracy, precision, recall, F1 score, and AUC, with an overall recognition rate exceeding 85 percent for different accident severity levels, indicating the best comprehensive predictive performance. Among the 72 unsafe behavior–accident type combinations, “violation of safety regulations and water inrush accidents” and “improper command and supervision and gas accidents” were identified as the most representative high-risk combinations, both predicted as major accidents. This finding suggests that coal mine accident risks are shaped by the joint influence of behavioral deviations and situational factors. Furthermore, a risk evaluation mechanism was introduced to quantitatively rank the 72 combinations, providing a theoretical basis for graded warning and differentiated prevention of unsafe behaviors in coal mine enterprises.
Design of a coal-rock particle collection system for shearer cutting operation#br#
2026, 58(7):  226-232.  doi:10.11799/ce202607028
Abstract ( 27 )   PDF(mobile) (2250KB) ( 3 )  
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Mining operations release large quantities of particulate matter as coal and rock strata are disrupted by drilling, blasting, and mechanical excavation. The physical (e.g., size and morphology) and chemical (e.g., ash and sulfur content) properties of these particles are highly correlated with the in-situ characteristics of the coal-rock body. Real-time acquisition of spectral, image, and compositional data from these particles enables rapid identification of geological materials, providing dynamic feedback for intelligent mining. However, particle dispersion and the presence of flammable gases such as methane in fully mechanized mining faces pose safety and technical challenges for conventional analysis methods. Here we report a compact, explosion-proof sampling and analysis device based on aerodynamic separation. The system integrates a negative-pressure fan, cyclone separator,? pressure sensor, and control module for sampling, transport, and analysis. We use a computational fluid dynamics–discrete phase model (CFD-DPM) to simulate and optimize the internal particle separation process, with separation efficiency and total pressure drop as the primary metrics. The device achieves over 95% separation efficiency under sealed negative pressure. CFD-guided structural design improves classifier stability and transport continuity. A two-axis platform transfers quantified particles into a sealed chamber for rapid spectral and compositional analysis. This system enables adaptive, in-situ coal-rock discrimination and offers a scalable solution for intelligent, unmanned mining operations.
Research on wireless communication technology across screw drill tool for near-bit data from measurement while drilling#br#
2026, 58(7):  233-240.  doi:10.11799/ce202607029
Abstract ( 35 )   PDF(mobile) (2402KB) ( 7 )  
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To advance the development of near-bit measurement while drilling technology for underground coal mines, the feasibility of Bluetooth, electromagnetic wave and acoustic signal transmission was compared based on an analysis of the unique underground coal mine application scenarios. Bluetooth was selected as the preferred method for near-bit data transmission, and a wireless communication technical scheme across screw drilling tools was proposed. The transmission characteristics of Bluetooth wireless signals in water were investigated, and a wireless communication simulation model was established to determine the effects of transmission power, transmission medium, and transmission distance on Bluetooth signal strength. On the basis of overall scheme design and simulation analysis and optimization, the structure, circuitry and programs were developed, and an across screw tool wireless communication device was fabricated. Laboratory water circulation tests were conducted, and the functions of power supply, data acquisition and transmission were executed normally. The theoretical analysis, simulation results and laboratory test results were in good agreement, confirming the rationality and feasibility of the signal transmission characteristic analysis. A surface drilling test was carried out at a test base, with a footage of 249 m. The device provided a wireless channel for near-bit parameters, including gamma, torque and vibration, to be transmitted across the PDM drill, enabling two-way interactive communication. This work provides key technical support for the development of near-bit MWD technology for underground coal mines.