Abstract:The landslide of open-pit coal mine with soft rock slope in eastern Inner Mongolia has the characteristics of multi-polarity and rotation.In order to explore the formation mechanism and deformation mechanism of landslide,a multi-stage rotational land-slide in eastern Inner Mongolia was selected as the research object.Based on the analysis of the basic characteristics of the multi-stage rotational landslide in the study area,the variation law of the mechanical properties of soft rock under different water contents is discussed through the indoor rock and soil physical and mechanical properties test.Combined with global navigation satellite sys-tem(GNSS)slope monitoring data and the stress state of the landslide,the motion characteristics of different positions of the sliding body and the migration law of the sliding body itself,the migration state of each stage of the landslide,the stress action mode of each position of the landslide body are analyzed.Through the calculation of slope stability,the stability of the slope sliding along other weak layers and the stable state of the slope sliding along the weak layer at different depths are analyzed,and the later deformation trend of the landslide is speculated.Based on the numerical simulation method,a three-dimensional slope model of 1 500 m×1 000 m×360 m is established.By analyzing the changes of displacement and equivalent plastic strain in the process of slope deformation,the instability mode of multi-stage rotational landslide is revealed.The results show that the soft rock of slope is greatly affected by groundwater,and the formation of landslide is controlled by the weak layer of soft rock,which is the main factor of progressive de-formation of rock and soil mass;the landslide has a tendency to expand to the south and to the deep,the whole landslide deformation process can be divided into four stages:landslide incubation and weak layer activation,landslide creep and accelerated instability,landslide expansion and main sliding surface formation,landslide multi-stage expansion and instability.

Abstract:To reduce unsafe behaviors among miners and decrease coal mine accidents,this study takes a work stress perspective and employs high-validity and high-reliability scales to measure miners'work stress and unsafe behaviors across various dimensions.A structural equation model is constructed to explore the impact of different dimensions of work stress on unsafe behaviors,revealing their respective effects.On this basis,a system dynamics model of miners'work stress on unsafe behaviors is constructed,and the ef-fect of each dimension of work stress in intervening in unsafe behaviors is simulated and analyzed.The results of the study indicate that:each dimension of miners'work stress is positively correlated with unsafe behaviors,with the ranking of their effects on unsafe behaviors as follows:environmental stress(0.68)>job responsibility stress(0.50)=organizational system stress(0.50)>family en-vironment stress(0.40)>career development stress(0.28)>interpersonal relationship stress(0.15).Adopting various intervention strategies for work stress can all reduce the level of unsafe behaviors among miners.In terms of the onset time of intervention meas-ures,the intervention strategies for work environment stress have the shortest onset time.In terms of the effect of intervention meas-ures,the intervention effect of institutional rationality under organizational system pressure is the best.Improving the overall envir-onmental quality,promoting the clarity of rights and responsibilities,enhancing the smoothness of communication,strengthening the support from superiors,improving the understanding of support and optimizing the rationality of the system are effective measures to relieve the work stress of miners and reduce the occurrence of unsafe behaviors.

Abstract:As a large coal storage yard,coal bunker is prone to spontaneous combustion due to air leakage and chimney effect.In or-der to study the disposal effect of liquid CO2 on spontaneous combustion of coal bunker,a liquid CO2 cooling test bench was built to simulate the structure of coal bunker.The temperature variation laws of the coal bunker during the injection of liquid CO2 and after the injection was stopped were tested,and the variation of the temperature field in the high-temperature area was analyzed.The res-ults show that during the injection of liquid CO2 into the coal bunker,the main cooling areas are concentrated at the liquid CO2 re-lease port and the seepage passage area;the average temperatures of the a,b,and d planes decreased by 22.7℃,33.0℃,and 10.2℃respectively.The cooling areas are the phase change cooling area,seepage cooling area,and convection cooling area respectively.After the injection was stopped,compared with the temperature before the injection,the temperatures in the upper and lower high-temperature areas decreased by 22.3℃and 16.8℃respectively.The temperature change of the coal body in the coal bunker mainly relied on the heat transfer through the temperature difference conduction of the coal body and the heat absorption by the sublimation of low-temperature dry ice.At the same time,it indicates that during the fire extinguishing process in the coal bunker.

Abstract:In order to study the supporting mechanism of rock burst roadway supported by rock bolt-foamed aluminum,uniaxial compression tests were carried out on eight kinds of rock bolt-foamed aluminum combined supporting anchors with different anchor numbers and foamed aluminum thickness conditions,and the mechanical properties and failure mechanism of the anchors under dif-ferent supporting parameters were studied.By extract that acoustic emission characteristic values relate to the rock burst from the acoustic emission signals of the anchored body under different support parameters in the uniaxial compression process,the evolution law of the acoustic emission characteristic values of the anchored body and the correlation between the acoustic emission character-istic values and the support parameters,the mechanical parameters of the sample and the parameters of the rock burst tendency of the sample are studied.The results show that aluminum foam can improve the strength and toughness of the anchor body,improve the elastic energy dissipation capacity of the system,reduce the elastic energy released in the form of mechanical energy in the system,and then improve the ability of the anchor body to resist impact damage;the acoustic emission in count and energy evolution present three-stage characteristics,in which the time proportion of the slow rising stage is positively correlated with the thickness of the foamed aluminum,and the phenomenon of"vertical growth"of the traditional support does not appear during the failure,which in-dicates that the foamed aluminum can effectively restrain the energy mutation by strengthening the rigidity and absorbing energy through large deformation.A quantitative relationship model was established between the acoustic emission parameters and the mechanical parameters,support parameters,and impact tendency parameters.The evolution of the acoustic emission b-value shows three-stage characteristics.The size of the b-value near the failure is linearly correlated with the thickness of the foam aluminum.When the thickness of the foam aluminum is 5,10,15,and 20 mm,the b-values are 0.069 07,0.081 15,0.089 67,and 0.100 25,re-spectively.

Abstract:With the continuous increase of mining depth in coal mines,the occurrence of deep roadway engineering disasters in-duced by dynamic disturbances has become more frequent.In order to recognize the mechanism of disasters caused by dynamic loads,we use research methods such as theoretical analysis and numerical simulation to summarize the characteristics of dynamic loads in deep roadways.The deformation and failure characteristics of surrounding rock in deep roadways are analyzed around the two factors affecting the deformation and failure of surrounding rock,namely the peak value of stress wave and the stress wave delay.Taking the impact disturbance caused by the direct roof fracture of Zhujixi Coal Mine working face as the engineering back-ground,the evolution law of the fracture zone in the roadway is simulated and analyzed.The results indicate that there is a close rela-tionship between peak stress wave and stress wave delay and the failure of surrounding rocks;as the peak impact load increases,the ultimate strength and peak strain of rock specimens also continuously increase,however,the rate of increase in ultimate strength gradually slows down,the rock specimens gradually form a"V"-shaped shear surface from bottom to top,leading to overall failure;in aspect of load delay,with the increase in load delay,there is a tendency for an increase in the ultimate strength of rocks,with little impact on peak strain,and the failure of rock specimens exhibits a development pattern from top to bottom;with the increase of peak stress wave,the range of tensile fracture zones and shear fracture zones around the roadway continuously expands;as the stress wave delay increases,the range of tensile fracture zones gradually decreases,while the range of shear fracture zones gradually increases.

Abstract:With the acceleration of the intelligent process of coal mine,the accuracy and real-time performance of fault diagnosis of coal mine equipment are more and more critical,which plays an important role in ensuring production efficiency and the safety of miners.However,in the actual fault diagnosis work,there may be a variety of problems such as data missing,data anomaly and net-work transmission,which affect the real-time and high accuracy performance of fault diagnosis.Therefore,in order to meet the re-quirements of heterogeneous fault signals of coal mine equipment and obtain real-time state feedback,an intelligent fault diagnosis method for coal mine equipment based on cloud-edge collaboration is proposed.This method combines the more powerful comput-ing capacity of the cloud server and the close transmission distance of the edge server to provide a more efficient and accurate fault diagnosis solution.This method preprocesses the monitoring data of coal mine equipment at the edge end.With the help of random forest algorithm,the isolation forest algorithm,transform domain filtering method and other algorithms,the noise in the data is re-moved,the missing values are filled,and the outliers are identified to ensure the integrity and accuracy of the data.After these pre-processing steps,the data is sent to the cloud server.After receiving the data,the cloud server further trains the universal fault dia-gnosis model.Firstly,the local features of the data are automatically extracted by the convolutional neural networks(CNN).Then,the Bi-directional gated recurrent unit(BiGRU)is used to learn the temporal dependencies of the data.The convolutional block atten-tion module(CBAM)is combined to assign weights to different features to improve the diagnostic performance of the model.After the cloud server completes the training of the complex model,the trained model parameters are sent to the edge server in time.At the edge server,the lightweight learning model ShuffleNet V2 updates its parameters according to those received from the cloud server.After the update,it can quickly adapt to the patterns learned by the cloud-trained model and perform real-time fault diagnosis on coal mine equipment.Through simulation experiments,the effectiveness of the proposed method is proved,and the accuracy of real-time fault diagnosis at the edge server can be improved to 99.7%.This high accuracy indicates that the proposed cloud-edge collaborative intelligent fault diagnosis method can timely identify different types of faults in coal mine equipment,which can effectively ensure the safety and efficient operation of coal mine production.

Abstract:To investigate the impact of various operations in open-pit coal mines on dust pollution,Zhonglian Runshi Xinjiang Open-pit Mine was selected as the engineering background.Field measurements of dust concentration under the influence of dual dust sources were conducted,and the dust generation mechanism of open-pit coal mines was analyzed.By establishing a mathematical model for dust diffusion from dual sources in open-pit mines and using SolidWorks software to construct a proportional geometric model,the distribution characteristics of coupled dust source migration were further studied.The results indicate that during truck loading and transportation,large particles of dust settle rapidly due to centrifugal force and gravity while particles smaller than 5 μm are difficult to settle.Simulation results show that within 0 to 50 seconds,the dust mass concentration mainly changes around the dust generation area.From 50 to 150 seconds,the dust moves along the airflow direction and forms a vortex.After 150 seconds,some of dust settles or escapes;within 200 seconds,the dust diffusion distance increases with the increase of the time.The dust mass concentration is the highest at the center of the dust source and gradually decreases as the diffusion distance increases.In the case of dual dust sources,the dust mass concentration is the sum of the dust mass concentrations of different dust-generating area dust sources and each virtual source,moreover,large particles are prone to settle.

Abstract:With the continuous expansion of mining scale in Weibei Coal Field in China,stope floor is increasingly threatened by the high confined water in the underlying Ordovician limestone,which leads to an obvious increase in the frequency of water inrush in the floor.In order to study the failure characteristics of stope floor,a mechanical model of stope floor strike is established based on the mine pressure theory.MathCAD software is used to generate the contour maps of vertical stress,horizontal stress and shear stress coefficient of floor rock mass along the working face during periodic pressure.According to Mohr-Coulomb yield criterion,the fail-ure characteristics of stope floor are determined.The results show that:when periodic pressure is applied,the maximum failure depth of stope floor along the working face is about 15 m,which occurs at the front of coal wall and forms a failure pattern of"deeper in front and shallower in back",approximately"scoop shape".FLAC3D simulation results show that the maximum failure depth of stope floor gradually tends to be stable with the increase of the advancing distance of working face.When the stope stope is ad-vanced to 140 m,the maximum failure depth of stope floor is stable at 15.5 m,which is very close to the failure characteristics of stope floor in confined water obtained by theoretical analysis.The current evaluation method of water inrush coefficient in Rules for Coal Mine Water Prevention and Control has certain limitations.It does not consider the influence of floor disturbance and failure depth on the thickness of water barrier layer,a formula for calculating the thickness of Ordovician limestone aquifer roof grouting re-construction is put forward.For the complex geological and hydrogeological conditions of Chengcheng No.2 Mine,a double-layer regional control network borehole structure with plane intersection and vertical offset is adopted-featuring a lower"thickness-pre-serving control layer"and an upper"inspection and reinforcement layer",so as to seal the karst fissures at the top of the Ordovi-cian limestone aquifer,and transform the top of the Ordovician limestone aquifer into a weak aquifer or water barrier layer,so as to explore and block the water channel and increase the thickness of the water barrier.

Abstract:In order to accurately assess the psychological load level of personnel in the process of coal mine hoist operation and ef-fectively reduce coal mine safety accidents triggered by excessive psychological load of personnel,firstly,by simulating coal mine hoist operation and combining with the N-back auditory subtask,three difficult task scenarios of low,medium and high difficulty were designed,and physiological signals(ECG,EDA and RESP)were collected from 18 experimental personnel,and at the same time,the NASA task coad index(NASA-TLX)subjective scores and the number of sub-task errors,and the normality test and hypo-thesis test were used to obtain the significance indicators.Secondly,based on the significance indexes,three machine learning meth-ods,namely,support vector machine,random forest and K nearest neighbor,were used to construct a mental load assessment model for operators.Finally,the classification accuracy of different physiological signals and combinations under the three machine learn-ing algorithms is compared.The results showed that:with the increase of sub-task difficulty,the subjective scores increased signific-antly,and the number of sub-task errors increased significantly;there were significant differences in the mean heart rate value(meanHR),the standard deviation of the heart interval(SDNN)and the ratio of the NN50 divided by the total number of NN inter-vals(PNN50)among the ECG indexes,and skin conductivity(SC)among the dermatoelectric indexes,and the respiratory indexes did not have a significant differences.The classification and recognition effects showed that:the accuracy of the constructed mental load assessment models differed in different physiological modalities;the accuracy of the classification model based on bimodal physiological signals was generally higher than that of the unimodal physiological signal classification model;and the random forest classification model in the bimodal modality(ECG+RESP)had the highest accuracy,with a recognition accuracy rate of 86.5%.

Abstract:Borehole grouting for sealing the holes is one of the main technical means for gas extraction,the quality of hole sealing directly determines the extraction effect.In order to improve the effect of grouting and plugging,the collected rock samples were drilled and slit,and the rock samples with different numbers of slits were grouted and plugged to make slit grouting specimens,and based on the coal-rock triaxial compression test system,triaxial compression mechanical test was carried out on the specimens to get the compression strengths of grouted specimens with different numbers of slits.The industrial CT scanning equipment was used to scan the compressed specimens to get the two-dimensional fracture network characteristics of the specimens after destruction,and AVIZO image analysis software was used to identify the CT scanning results of different specimens and analyze the two-dimension-al development characteristics of the fracture of different specimens after compression,and at the same time,VG Studio MAX im-age analysis and processing software was used to carry out three-dimensional reconstruction,and analyze the number of slits and fracture rate of the specimens,fractal dimension and Euler number.The results show that:the data of slits directly affect the mechan-ical properties of the borehole grouting specimens,with the increase of the number of slits,the strength of the specimens is weakened;according to the industrial CT scanning results of the damaged specimens,the analysis of the development of the cracks,and the complexity and connectivity of the fracture network found that the slits have a guiding role in the expansion of fracture de-velopment of the load-bearing body,and the predominant angle of the development of pore cracks is±45 °,and the development of cracks in this direction is more prominent;with the increase of the number of slits,the development of fractal dimension and Euler number are more prominent;the fracture rate and 3D fractal dimension increase linearly with the increase of the number of slits,while the Euler number decreases linearly with the increase of the number of slits in the boreholes.The grouting of slits in boreholes is conducive to improving the quality of hole sealing,but too many cut slits will deteriorate the quality of hole sealing.

Abstract:The unsafe behavior of underground miners is one of the main factors leading to mine safety accidents,and real-time,ac-curate identification and early warning of such behaviors are critical for improving mine safety management.The rapid advancement of artificial intelligence(AI)vision technology has drawn significant attention to its application in recognizing unsafe behaviors among miners,demonstrating considerable technological advantages.This review aims to systematically explore the progress in AI vision technology for unsafe behavior recognition and to examine its current application status,challenges,and future directions in mine safety management.Unsafe behaviors are categorized into static and dynamic behaviors based on their characteristics to recog-nition methods suitable for different behavior types.The key technical processes involved in behavior recognition,including data ac-quisition,object detection,behavior recognition,and classification,are thoroughly discussed,along with the main methodologies and technological innovations found in current studies.The performance of various algorithms in real-world mining environments is also analyzed.Research shows that AI vision technology has made significant progress in identifying unsafe behaviors of miners and can effectively improve the ability of mine safety supervision.However,it still faces some challenges.Complex factors such as light changes,dust interference,and target occlusion in the mine environment still have a considerable impact on the recognition accuracy,resulting in certain limitations of the existing methods.On the other hand,the lack of data resources has also become an important factor restricting the development of technology.Currently,the available datasets of miners'unsafe behaviors are limited in scale,making it difficult to cover multiple behavior types and complex scenarios,which affects the training effect and practical applicabil-ity of the recognition model.Meanwhile,although some studies have begun to explore multimodal information fusion,this direction is still in the development stage and the related technical system is not yet mature.Future research should further enhance the adapt-ability of AI vision technology in complex mine environments,optimize the algorithm structure to reduce computing costs,and ac-celerate the construction of high-quality and diverse datasets of miners'unsafe behaviors to support more accurate and efficient beha-vior recognition.Meanwhile,the development of multimodal fusion technology is expected to further enhance the robustness of be-havior recognition and provide a more intelligent solution for mine safety management.

Abstract:Aiming at the problems of difficulty in controlling the stability of surrounding rock and high impact risk in the mining of variable face stope,taking I010206 working face of Kuangou Coal Mine in Xinjiang as the engineering background,FLAC3D numer-ical model and periodic fracture mechanical model of working face roof are established,and the stress and energy evolution charac-teristics of surrounding rock in variable face stope are analyzed,and the mechanism of induced impact caused by overburden failure in working face is revealed,and the technology of hydraulic fracturing roof to relieve danger in advance is put forward,and the pres-sure relief effect is compared and tested.The research results show that:during the mining period,with the increase of the width of the working face,the peak value of the advanced abutment pressure and the degree of stress concentration increased significantly,the peak value of the advanced abutment pressure increased from 13.05 MPa to 16.67 MPa,and the peak value of strain energy density increased from 46.77 kJ/m3 to 96.72 kJ/m3,during the mining process of the working face,due to the presenece of hard roof,large areas of unsupported roof are prone to form,the elastic strain energy accumulated with the roof significantly increases.When the hard roof reaches its limit span,it breaks and releases a lot of energy,which is easy to cause the mine pressure to appear;after the working face is widened,the roof load increases,and the overburden load is transferred to the coal body in front of the working face and the coal bodies inclined to the upper and lower sides of the working face.The stress concentration is higher after the abutment pressure of I010408 working face in B4-1 coal seam is superimposed with the abutment pressure of I010206 working face in B2 coal seam after mining,and the lateral abutment pressure of goaf and the high static load and the high dynamic load of roof caving in a large area are more likely to induce rock burst.In view of the site impact risk factors such as high energy concentration of the roof and strong dynamic load disturbance when the hard roof collapses,the advanced weakening measures of hydraulic fracturing roof are put forward.Through the pressure relief effects of hydraulic fracturing and pre-splitting blasting compared and tested by support pressure and micro seismic data,it is found that after using hydraulic fracturing technology,the weighting step of roof in working face is reduced,micro seismic signals show the characteristics of low energy and high frequency,and the impact risk of working face is obviously reduced,which ensures the safe mining of working face.

Abstract:By systematically sorting out the classification of mining accidents in China,mining accidents are classified into two cat-egories:underground accidents and surface accidents,and their characteristics and patterns are analyzed in depth.Based on the actu-al scenarios and combat characteristics of mine rescues,the method of demand analysis and equipment principle exploration was ad-opted to study the equipment allocation system for mine accident rescues.The research subject is one squadron,each consisting of three squads.Firstly,a detailed analysis was conducted on the equipment requirements for five categories of mining rescue teams,in-cluding detection and search,drilling and rescue,demolition and support,mine drainage,and firefighting and rescue.The specific functions for each type of equipment in different accident types and rescue scenarios were clarified.Each squadron should be equipped with detection and search equipment such as 3D laser scanners,radar life detectors,audio and video detectors,as well as drilling and rescue equipment such as horizontal small-diameter drilling rigs in underground mines.Secondly,the principles of equipping advanced and applicable equipment for mining rescue teams were discussed,including equipping some equipment accord-ing to the team,some equipment according to the squadron,equipping according to actual needs,and selecting and matching some equipment.Once again,the principle of equipment priority allocation has been determined,and key allocation directions such as un-derground life search equipment,underground drilling and rescue equipment,underground drainage pumps and pipelines,and open-pit mine detection equipment have been proposed.Finally,suggestions were put forward for the work of mine accident rescue equip-ment from the two dimensions of equipment research and development and equipment configuration,such as strengthening the re-search on technical equipment such as underground reconnaissance drones,roof displacement monitoring equipment,airbag sealing,lightweight underground drainage pumps,etc.,strengthening the equipment for underground life search,underground drilling and rescue,as well as detection equipment such as slope radar and 3D laser scanners.

Abstract:With the increase in the depth of coal resource mining and the extension of underground engineering to deeper areas,the problem of sandstone pore water damage has become increasingly prominent.Chemical grouting is an effective method for the treat-ment of water damage in deep pore rock layers.However,it still faces technical bottlenecks such as low filling rate and poor seepage reduction effect.In order to study the laws of filling,seepage,diffusion and reducing seepage of chemical grout in pores,the near-transparent quartz sands and neutral silicone adhesives were used to prepare the porous medium model material,and the self-con-structed plexiglass tube was used to prepare the experimental model,and stained urea-formaldehyde resin grout as the grouting li-quid.We realized visual observation of grout seepage diffusion process,measured the porosity,seepage,seepage reduction rate and filling rate of the porous medium,and further investigated the effects of chemical grout on the filling characteristics and seepage re-duction mechanism of the porous medium.The results showed that when the grout flows through the saturated cemented porous me-dium,there is no obvious interface between the seepage range and the non seepage range,and the grout pore-filling rate tended to de-crease with increase of the distance from the grouting entrance;the seepage law of chemical grout in saturated porous media is between the piston and non-piston type displacement modes;within the range of grout diffusion,the seepage of the model material is significantly reduced,with the measured water reduction rate exceeding 97%.As the distance from the grouting inlet increases,the water reduction rate shows a decreasing trend.

Abstract:Static crushing agent(SCA)has the advantages of good safety,no harmful gas and no vibration.It is widely used in rock crushing engineering of mine or underground engineering.Aiming at the roadway side expansion project and environmental condi-tions of a mine in Shanxi Coking Coal,the suitable type of static crushing agent was selected.The mechanical parameters of road-way surrounding rock and the expansion performance of SCA were tested by laboratory test,numerical simulation and field engin-eering test.The fracturing law of SCA on roadway side rock under multi-row drilling conditions was studied,and the reasonable fracturing drilling parameters and row spacing distribution were obtained.The construction technology of static crushing agent grout-ing method was proposed.The results show that the smaller the hole spacing is,the better the crushing effect of SCA is,and the shorter the crushing time is.Under the premise of ensuring the crushing effect,it should also be combined with the construction effi-ciency of the production team 8 h shift system,and it is recommended to use the 300 mm drilling row spacing arrangement;the nu-merical simulation analysis obtained the stress distribution and fracture propagation law of the multi-row borehole fracturing process.The research results show that multi-row borehole SCA fracturing can safely and efficiently deal with the fracturing engineering of free surfaces such as side expansion,bottom lifting and roof cutting in coal and rock roadways.

Abstract:With the excellent adaptability,flexibility and efficiency,trackless tyred vehicle has gradually become the core compon-ent of modern coal mine auxiliary transportation.Due to the poor lighting conditions and complex scene along the auxiliary trans-portation line in coal mine,the accidents of the trackless tyred vehicle occur frequently,seriously threatening the life safety of operat-ors along the auxiliary transportation line.Aiming at the problem of reliable identification of intruders in front of underground track-less tyred running along the auxiliary transportation line of coal mine,a reliable identification method of personnel along the auxili-ary transportation line based on infrared/visible light dual-mode fusion technology was proposed.In the improved method,an in-frared/visible dual-mode fusion network based on multi-scale feature interaction module is constructed,which combines multi-scale fusion and cross-scale fusion to effectively preserve the structural details of infrared images and visible images by designing the win-dow-based multi-head self-attention and shifed window-based multi-head self-atention.The simulation results show that in pro-cessing infrared/visible light fusion,the proposed dual-mode fusion technology has higher peak signal-to-noise ratio,structural fea-ture similarity index,mean square error and correlation index than two commonly used image fusion networks such as the Dif-Fu-sion and SwinFusion.The post-processing method of YOLOv8 target recognition network is optimized,the DIoU-NMS structure is used to improve the accuracy of target positioning,reduce the missed detection rate of the algorithm,and realize the reliable identi-fication of auxiliary transportation tunnel operators.With the improvements,the reliable identification of auxiliary transportation roadway operators is realized.Based on the actual images of the coal mine scene and the processing expansion,an effective data set for the detection task of personnel along the auxiliary transportation in the coal mine is established.The industrial experiment were carried out in Wangjialing Mine of China Coal Huajin Group Co.,LTD.,and the results show that the accuracy rate of personnel de-tection and the recall rate of intruders can reach 97.58%and 98.53%respectively.

Abstract:In mine accident rescue operations,the underground environment becomes extremely complex.Obstructions such as tun-nels and rocks,coupled with changes in physical space and the presence of high-concentration gases,lead to attenuation,reflection,refraction,and the formation of multiple propagation paths of ultra-wide band signals.These factors make Non-Line-of-Sight(NLOS)and multipath effects very pronounced,which severely affects positioning accuracy.To address these issues,a novel al-gorithm based on a prior-data-driven Gaussian mixture model(GMM)and acceleration-collaborative adaptive extended Kalman fil-ter(PGA-AEKF)is proposed.The algorithm first uses the Akaike information criterion and the Bayesian information criterion to de-termine the number of Gaussian mixture distributions.It then employs particle swarm optimization and simulated annealing al-gorithms to optimize the expectation maximization algorithm to determine the parameters of each distribution.The improved GMM is used to fit the collected time-delay prior data distribution.Subsequently,the real-time NLOS probability value of the scene is ob-tained using geometric methods,and an adaptive factor is generated in combination with the results of abnormal acceleration judg-ments of pedestrian or vehicle motion.Finally,the adaptive factor is used to adjust the size of the noise covariance matrix to improve positioning accuracy.To verify the performance of the algorithm,trajectory tracking experiments were conducted in Yunlongshan Tunnel and underground space smoke environment.The results show that in the tunnel scenario,the proposed PGA-AEKF al-gorithm achieved a significant reduction in average error compared to pure inertial measurement unit algorithm,least squares meth-od,and extended Kalman filter algorithm,with reductions of approximately 86.67%,69.23%,and 38.46%,respectively.In the smoke scenario,the average error was also significantly reduced by approximately 83.78%,60.00%,and 25.00%compared to the aforemen-tioned algorithms.The study shows that the PGA-AEKF algorithm can effectively deal with NLOS interference,suppress noise and errors.

Abstract:To investigate the differences in pore structure with different particle sizes when coal body immersed in different amounts of water,coal samples with three particle sizes and four degrees of immersion were prepared using fat-coal(FM)and coking coal(JM).The low-temperature nitrogen adsorption experiment was conducted to determine the pore structure of coal,and fractal theory was employed to accurately quantify the pore structure.The study analyzed the differential effects of water immersion degree and particle size on coal pore structure.The research results show that under the same degree of immersion,as the particle size decreases,the specific surface area,single-layer saturated adsorption capacity,total pore volume,and isothermal adsorption capacity of the coal sample all show an increasing trend,and the change in specific surface area is the most obvious.The BET specific surface area of coal samples with particle size of 0.15-0.18 mm is about three times that of coal samples with particle size of 0.25-0.85 mm.The single-layer saturated adsorption capacity is positively correlated with the change in specific surface area,and the growth of JM is particularly significant at the minimum particle size.The analysis of total pore volume shows that the pores are mainly mesopores,and after water immersion,some coal samples exhibit the phenomenon of large pore collapse and an increase in mesopores,resulting in a decrease followed by an increase in pore volume.The isothermal adsorption curve shows that the adsorption process conforms to the typical characteristics of mesoporous materials,and the adsorption capacity of coal samples with the smallest particle size(0.15-0.18 mm)is always the highest.The effect of immersion has a dual nature:at low immersion rates,water occupies large pores,lead-ing to structural collapse and a decrease in specific surface area and single-layer saturated adsorption capacity;when the immersion water is high,the dissolution effect promotes the secondary development of pores,and the relevant parameters increase accordingly.The fractal characteristics further indicate that the fractal dimension changes of coal samples after water immersion do not follow a single law,but are jointly regulated by the degree of immersion and particle size.The degree of immersion and sample size are key factors leading to differentiated changes in coal pore structure.

Abstract:The mining environment of deep coal seam has the characteristics of high confined water pressure,high ground stress and strong disturbance.Mining is more likely to induce high-pressure karst water to flow into the mine along the weak zone of geologic-al bodies such as faults.In order to comprehensively and accurately predict the fault water inrush from coal seam floor in Huangyuchuan Coal Mine,geophysical methods such as three-dimensional seismic and transient electromagnetic were used to ex-plore the fault distribution in the study area and determine the fault location and water conductivity.Aiming at the problem that it is difficult to quantify and predict the potential water inrush risk of working face crossing fault in pressured area,the factors affecting fault stability are screened and extracted,and the fuzzy analytic hierarchy process(FAHP)and grey correlation analysis(GRA)risk evaluation model are integrated to construct a FAHP-GRA coupling fault zone water inrush risk evaluation model.FAHP is used to determine the weights of 10 factors affecting fault water inrush,and GRA is used to determine the correlation degree of each index in the mathematical model.The risk level of fault water inrush is obtained by the correlation degree of each index obtained by evalu-ation.The results show that the weight of confined water pressure in the evaluation model is the largest(0.146 7),while the weight of mining depth and fault water conductivity is the smallest(0.029 34),and the grey weighted correlation degree of hydrogeological conditions is the largest(0.253);the NNE-NE trending faults in the pressured zone are mainly high-risk and relatively dangerous,and the NNW-NW trending faults are mainly relatively safe and safe.The evaluation model is suitable for the investigation of water in-rush risk in coal mines with complex geological structures,and realizes the purpose of"effective evaluation,rapid diagnosis and pre-cise prevention"of fault water inrush.

Abstract:The small area pre-grouting of water-bearing layers is often used in shaft excavation,clarifying the slurry diffusion law is the basis for determining the slurry diffusion range and formulating the grouting schemes.Different types of grouting models for a single fracture considering the fluid-solid coupling effect were established.The influences of factors such as grouting pressure,grout density,and fracture opening on slurry diffusion and fracture deformation were analyzed.The grouting slurry diffusion tests for smooth single fractures and rough single fractures were conducted using the rock mass fracture grouting test system.The research results show that the farther the distance from the grouting hole,the smaller the slurry diffusion radius within the same period,that is,the slower the slurry diffusion speed.When the slurry spreads to a certain distance,the grout pressure at different grouting rates all drops to the same pressure.Increasing the number of grouting holes is more effective than increasing the grouting speed.The greater the roughness of the crack,the less the amount of slurry in the length direction of the crack,and thus the less the total amount of slurry required,that is,the shorter the grouting time.