摘要：Resilience,both as a conceptual perspective and an analytical framework,has increasingly garnered interest for its utility in examining the dynamic interactions between human societies and natural ecosystems.This approach has emerged as a pivotal tool for exploring human-land relationships,spurring notable developments in corresponding models and methodolo-gies.Mining areas,characterized by intense human activity disturbance,serve as typical environments for the application of social and ecological resilience.This paper delineates the core concepts,research framework,and assessment methods of social and ecological resilience in mining area(SERMA),and provide a comprehensive overview of the principal applica-tions,limitations,proposed enhancements,and future development of SERMA from conceptual,theoretical,and practical standpoints.SERMA studies encompassing various domains,including assessment,mechanism,dynamic change,predic-tion,determinants,and management guidance.Nonetheless,the current research on SERMA confronts several challenges.Firstly,the absence of a standardized framework for evaluating resilience studies using comprehensive indicators makes it challenging to compare them.Secondly,there is a paucity of large-scale and long-term SERMA studies.Thirdly,insufficient analysis of the mechanisms such as resilience thresholds and regime shift,and corresponding empirical research.The study of SERMA involves theory of resilience,a critical examination of mining and reclamation processes,as well as related ecological and socio-economic processes.Future advances in resilience and social-ecological system(SES)research,such as the quantitative study of resilience mechanisms,are expected to gradually be applied to mining systems.

摘要：Due to the limitations of widely used energy spectrum and spectral analyses for the determination of trace elements in coal,the modes of occurrence of Li still remains unclear.This study investigated the distribution of Li in selected bulk samples and in-situ kaolinite particles in the No.6 Li-rich coals from the Haerwusu Mine of the Jungar Coalfield using ICP-MS and LA-ICP-MS.The results reveal an elevated Li concentration in the lower section of the No.6 coal with high Sr/Ba ratio compared to the upper section with more terrigenous mudstone along the vertical profile.LA-ICP-MS mapping and spot analyses results showed that Li was concentrated in kaolinite but occur in variations in the concentrations of Li among different types of kaolinite.The concentration of Li in kaolinite is ranked as follows:cryptocrystalline kaolinite(2225.83 ppm)＞vermicular kaolinite(651.49 ppm)＞altered K-bearing kaolinite(593.44 ppm)＞clastic kaolinite(478.68 ppm).The in-situ concentration of Li in kaolinite is much higher than that of the bulk samples,indicating that kaolinite is the dominant host mineral for Li as well.The Al2O3/TiO2 and Nb/Yb-Zr/TiO2 ratios indicate that Li in No.6 coal pri-marily originated from Paleoproterozoic granite in the Yinshan Mountain and felsic volcanic ash.Seawater leaching has a critical influence on the redistribution of Li in the coal from the Haerwusu Mine or even the whole Jungar Coalfield.

摘要：The rock-concrete interface has a significant influence on the stability of rock-concrete structures in coal mine roadway that are vulnerable to tensile loads.In this study,direct tension tests in combination with laser scanning and acoustic emission techniques were used to study the influences of loading angle and strength contrast on tensile behavior of rock-concrete interface.Results show that peak strain and tensile strength of granite-concrete specimens are lower than those of granite and concrete.Acoustic emission(AE)characteristic of the granite-concrete specimens differs from that of concrete and granite.With the loading angle increases,peak strain and tensile strength of the granite-concrete specimens increase,and the failure mode varies from the interfacial tensile failure to mixed tensile failure due to the increased contact area and decreased tensile stress applied on the granite-concrete interface.In addition,the accumulative AE counts of the granite-concrete specimen are also significantly affected by the loading angle;in particular,when the loading angle is sufficiently large,e.g.,55°,the accumulative AE counts sharply increase twice.Different strength contrasts between rock and concrete result in different failure characteristics of rock-concrete specimens under direct tensile loads.When tensile strength of rock is lower than that of concrete,failure often occurs in the rock section and the tensile strength and peak strain of the rock-concrete specimen is similar to that of rock.By contrast,when the tensile strength of rock is higher than of the concrete,failure appears at the interface,and rock-concrete interface dominates the tensile properties of rock-concrete specimens.The failure mode is domi-nated by the coupling effect of loading angle and strength contrast.The findings in this study are helpful in understanding the mechanical behaviour of rock-concrete structures under direct tension and applicable to the design and reinforcement of rock-concrete structures in coal roadway.

摘要：The use of lithium-ion batteries(LIBs)-operated underground mining machinery has gained tremendous momentum as a result of their numerous advantages.This includes their high energy density,long cycle life,high voltage delivery,low heat release,stability,negligible memory effects,and low carbon footprint.Battery operated vehicles are also preferred in underground mines for their flexibility.They do not emit harmful pollutants during nominal operations,making the work environment safer for miners.However,thermal runaway(TR)incidents can occur which presents risks to miners and underground infrastructure.Therefore,it is crucial to understand battery operations and their failure mechanisms.This article outlines the advantages of LIBs,the necessary precautions for their safe operations underground,the conditions and impact of TR events,battery management systems,handling LIB fire emergencies,and the research opportunities to promote safer and widespread use.

摘要：The shear behavior of fractured rock masses critically influences engineering stability,particularly in slope engineering.Overcoming limitations of conventional preparation methods,this study utilizes sand-powder 3D printing to fabricate rock-like specimens with controlled internal fractures.Direct shear tests systematically investigate fracture radius and number effects on strength evolution under constant density,with quantitative analysis revealing their differential contributions.The results show that:(1)The failure of sand-powder 3D-printed fractured rock-like specimens exhibits brittle characteristics.The shear stress-shear displacement relationship can be divided into five stages:compaction,elasticity,unstable develop-ment,peak,and post-peak.Crack initiation and propagation primarily occur from the late elastic stage to the peak stage.(2)An increase in fracture radius significantly reduces pre-peak shear stiffness,resulting in a smoother curve progression,while changes in fracture number have minimal impact on the stage-specific characteristics of the shear curve.(3)Shear strength decreases exponentially with increasing fracture radius,whereas an increase in fracture number leads to a linear reduction in shear strength.Moreover,the weakening effect of fracture number on shear strength becomes more pronounced with larger fracture radius.(4)Quantitative analysis shows that the influence of fracture radius on shear strength is 2.4 times greater than that of fracture number.This study broadens the understanding of the shear behaviors of fractured rock masses and reveals the key influence mechanism of fracture density on rock mass deformation and failure,and provides theoretical guidance for slope stability analysis and rock mass engineering design.

摘要：The acoustic emission(AE)method is commonly used to measure in-situ stress,while the Kaiser effect(KE)is usually affected by the stress history and specimen direction.In this study,three types of rocks were tested under uniaxial deflection loading at various deflection angles.Both the KE and the incomplete erasion phenomenon(IEP)were investigated,and the obtained in-situ stress using the AE method was compared with that obtained using the stress relief method.The results demonstrate that both the KE and the IEP exhibit directional independence.The rock type significantly affects the critical angle(θ),with marble showing a higher value(15°)compared to granite(10°)and red sandstone(5°).This is attributed to the initiation and development of interface cracks or crystal interfaces in mineral grains.The similar in-situ stress measured by the AE and stress relief methods suggests that small-angle deflection coring is applicable in engineering.This study provides a reference for in-situ stress measurement using the AE method.

摘要：Over the last decades,huge amounts of ash residues have been generated worldwide leading to increasing demand for viable recycling technologies.Magnetic separation is considered a promising option for sustainable management of these wastes.The present paper aims to review the recent advances in magnetic separation of ash residues to convert these waste materials into valuable commodities,minimizing negative environmental impact and in compliance with the circular economy requirements.Emphasis is placed on single magnetic separation techniques,multi-step separation procedures,and implementation of the magnetic separation in more complex separation schemes(in combination with particle-size fractionation,flotation,electrostatic separation,density(sink-float)separation,etc.)Novel and special approaches are mentioned as well(using organic solvents,selective magnetic coating,separation supported by thermal treatment or chlorination,methods for removal of non-magnetic components,magnetic separation applied on solubilized/precipitated compounds etc.).It discusses the latest literature results on the magnetospheres' morphology,chemical and mineral com-position,and elemental leachability.Particular attention is paid to the utilization perspectives of the magnetic fractions and the non-magnetic residues.Based on the existing research status,the paper also provides concluding remarks highlighting the most promising trends.Current limitations indicating suggestions for future research(including insights on how exist-ing approaches could be further improved)are mentioned as well.

摘要：Coal gasification fine slag(CGFS)is a solid waste produced in the process of coal gasification.The separation of residue carbon in CGFS is essential for its resource utilization.In this study,the basic physical properties of CGFS were analyzed and the effect of physical separation experiments were carried out.The gravity separation results indicated that the coarser particle size fraction achieved a good separation effect.The High-carbon product has a yield of 12.53％with an ash content of 16.84％,and the High-ash product has a yield of 17.85％with an ash content of 98.15％were obtained.Theoretical calculations indicated that the apparent density difference between residue carbon and ash minerals in the water phase environment was the basis for achieving separation.The Rich-ash product was further separated by magnetic separa-tion,and both magnetic field characteristics,water elutriation frequency and grinding time had impacts on the magnetic separation effect.Compared to gravity separation alone,the combined gravity-magnetic separation further enhanced the separation effect of residue carbon and ash minerals.The ash content of the Rich-ash product decreased from 80.56％to 69.52％due to the removal of high-ash Fe oxides,and the yield of combined separation tailings increased from 17.85％to 41.75％.The characterization results obtained through SEM-EDS,VSM,XRD and XRF analysis demonstrated signifi-cant differences in saturation magnetization,mineral composition and peak intensity among magnetic separation products,confirming that the feasibility of magnetic separation.The research findings contribute to a better understanding of the separation mechanism and provide a new separation process for efficiently enriching residue carbon from CGFS,also facilitate the step utilization of separation products.

摘要：Shale oil resources are abundant on Earth,of which hybrid sedimentary shale(HSS)oil is an important component,includ-ing high and medium-low organic matter content(TOC).Oil content,especially the oiliness gradation,is a key parameter for shale oil evaluation and numerous studies had been conducted.However,most studies concentrated on the HSS with high TOC,making oil content evaluation of the HSS with medium-low TOC challenging.The Paleocene Shahejie Forma-tion(E2s)shale in Dongpu Depression is a typical HSS with low-moderate TOC,showing great shale oil resource potential.Integrated geochemical characterization of 270 core samples were conducted and results show that,the E2s shale has fair-good hydrocarbon generation potential,with TOC ranging from 0.06％ to 3.6％(Avg.0.86％)and Ⅱ1-Ⅱ2 kerogen type in thermally mature.The hydrocarbon generation potential decreases with kerogen types changing from type Ⅰ to Ⅲ,but S1C and the oil saturation index(OSI)(S1*100/TOC＞100)increase from type Ⅰ to Ⅱ1,and then decrease from type Ⅱ2 to Ⅲ,indicating shale with type Ⅱ2 kerogen have the greatest oil content.This is related to the differences in hydrocarbon expul-sion efficiency caused by differential hydrocarbon generation potential and pore-microfractures evolution among shales with different kerogen types.Significant oil micro-migration occurred in E2s shale,with micro-migration quantity(ΔQ)ranging from-846 to 993 mg/g(Avg.-120 mg/g),and 90％and 10％shale exhibit hydrocarbon intra-micro-migration(ΔQ＜0)and extra-micro-migration(ΔQ＞0).The shale with type Ⅱ2 kerogen has the greatest intra-micro-migration.Based on S1C,TOC and OSI values and their evolution pattern,shale oil resources were classified into enriched,moderately enriched,less efficient and invalid resources,accounting for 11％,53％,16％and 21％respectively,with S1C thresholds of 3.5 and 0.5 mg/g,OSI threshold of 100 mg/g.Compared with previous grading criteria,the gradation criterion established in this study is relatively lower,which is mainly due to the lower TOC and clay mineral content in HSS.Enriched and moderately enriched resources are mainly shales with type Ⅱ2 kerogen,followed by type Ⅱ1 kerogen,and the E2s4U and E2s3L shale are the most favorable targets for further shale oil exploration.The established oiliness gradation criteria are applicable for the HSS with TOC in other parts of the world.

摘要：Accurately revealing the spatial distribution law of seismic displacement is significance for revealing the mechanism of dynamic load induced rockburst and guiding the dynamic support of roadway.This paper established the function of seis-mic displacement based on radiation energy,and compared the influences of fracture type,radiation energy,shear strength,fracture velocity and medium density on the seismic displacement.The results showed that the displacement amplitudes of surrounding rock caused by P-wave,SH-wave and SV-wave increased with the rising of radiation energy,and the rate of displacement amplitude also accelerated.The displacement amplitudes of seismic wave associated with tensile fractures are significantly higher than that with shear fractures.The spatial displacement amplitude of S-wave was significantly higher than that of P-wave by one order of magnitude.The peak value of P-wave displacement of shear fracture was concentrated in two planes at 45° angle to the fracture surface.For SH-wave and SV-wave components,peak values were mainly observed on the fracture surface and its orthogonal plane.The P-wave displacement on the orthogonal plane to the fracture movement was zero,the displacement field of SV-wave was distributed in four quadrants,and the displacement field of SH-wave was symmetrical.The higher the value of medium attribute,the more significant the damage effect of coal-rock seismic wave weakening,and the influence on the S-wave is greater than that of the P-wave.The displacement amplitude caused by seismic wave gradually increased with the rising of fracture velocity of coal-rock mass.The peak value of P-wave displacement increased linearly,and the peak value of S-wave displacement was nonlinear.The research results laid a theoretical founda-tion for dynamic support design for roadways.

摘要：Currently,regression prediction methods based on logging data is one of the main methods for analyzing gas content of coal seams.However,the complexity of logging parameters for deep coal seams and the scarcity of measured gas content data significantly affects the accuracy and generalizability of data regression models.Accurately predicting the gas content of coal seams under small-sample condition become a difficult point in deep coalbed methane(CBM)exploration.The Model-Agnostic Meta-Learning(MAML)and Support Vector Regression(SVR)algorithms are among the few suitable for small-sample learning,exhibiting strong adaptability under limited sample conditions.In this study,logging parameters are used as input variables to construct MAML and SVR models,and their performance in predicting gas content of deep coal seams across different regions and layers is compared.The results demonstrate that the MAML algorithm effectively addresses the complex relationships between gas content of deep coal seam and logging parameters.The prediction errors for test dataset and new samples are merely 3.61％and 4.52％respectively,indicating exceptional adaptability,robust generalization capabil-ity,and stable model performance.In contrast,the dependency of SVR model on input parameters restricts its accuracy and generalizability in predicting gas content in deep coal seams with varying geological conditions.Although achieving a test dataset error of 4.71％,the SVR model demonstrates substantially degraded performance when applied to novel samples,with prediction errors escalating to 12.46％.Therefore,the MAML model is selected to predict gas content in the unknown areas of the Baijiahai region.The prediction results reveal that the gas content of coal seams in the Xishanyao formation(J2x)ranges from 1.32 m3/t to 16.11 m3/t,while that in the Badaowan Formation(J1b)varies between 1.73 m3/t and 11.27 m3/t.Notably,the gas enrichment areas are predominantly distributed in well blocks adjacent to fault systems,such as wells C31 and BJ8,etc.,which align with the favorable geological conditions for deep CBM accumulation in the Baijiahai region.These spatial distribution patterns not only corroborate existing geological insights but also further validate the reliability of the MAML model in predicting gas content within deep coal seams.

摘要：Coal is formed from ancient plants through biochemical and physicochemical stages.Lignite gives a low amount of energy compared to higher rank coal.The Eocene Khadsaliya Formation lignite(Surkha mine)and shale(Khadsaliya mine)sediments were collected to investigate their evolution,maturity,and source rock potential.The main objectives of this study were to update and verify previous claim of possible hydrocarbon showings and to gain new insights about the petroleum potential and paleodepositional conditions using different geochemical analysis approach.The primary methodology employed in this study is the pyrolysis technique and complemented by petrographic analysis.Petrographic indices indicate that Khadsaliya shale and Surkha lignite were deposited in limnic and limno-telmatic conditions,respectively,with slow subsidence rates under mesotrophic hydrological condition.Significant concentration of corpogelinite indicates highly varying water table and low oxygen levels during peat accumulation.At the same time,the presence of funginite,framboidal pyrite,and relatively high sulfur in some studied samples shows marine water influence in the basin.The reflectance values(0.37％-0.57％)reveal that organic matter(OM)in Surkha lignites is immature,while immature to marginally mature in Khadsaliya shale.Furthermore,the pyrolysis data like Tmax(385 ℃-430 ℃)and production index(PI 0.02-0.13)also indicate immature to marginally mature OM.Oxygen index(OI)versus hydrogen index(HI),Tmax versus HI,and Total organic carbon(TOC)versus S2 plots of lignite and shale of Khadsaliya Formation indicate that the OM is mainly type Ⅲ kerogen and can act as fair to good source rock.The distribution of n-alkene/n-alkane doublets,o-Xylene,and 2,3-dimethylthiophene in the Py-GC pyrogram exhibits that most studied shale and lignite samples have type Ⅲ kerogen and the capability to produce mainly gas.

摘要：Changing political and market conditions have disrupted energy security.European economies are planning to utilize their own resources of energy raw materials,including consideration of the advisability of returning abandoned coal resources to use.The research using the proposed methodology examined the impact of the ongoing mine closure processes on the potential ability to develop the remaining deposit.It was found that the greatest influence on the availability of unclosed shafts was the active concession to extract minerals from the deposit and the availability of unclosed main plant facili-ties.The assessment of the possibilities of coal resources management in the deposits of liquidated mines has not been the subject of extensive scientific research so far.The information obtained can be used as a reference point for detailed analysis and multi-criteria evaluation,after which the decision maker makes the decision.The method is designed for liquidated mines,but with certain modifications it can also be used by mining companies.

摘要：In underground engineering fields,such as mining engineering,rocks are often subjected to cyclic loading,resulting in the deterioration of their mechanical properties,which poses a serious threat to engineering construction.Thus,investigating the mechanical response of rocks under cyclic loading is meaningful.Cyclic loading experiments were conducted on sandstone samples with different cyclic stress amplitudes(CSAs).First,the deformation characteristics and strain energy evolution were analyzed.The internal fracture extension and fragmentation characteristics of sandstone after failure were subsequently analyzed.Finally,the failure mechanism of sandstone was investigated.The results revealed that deformation,failure mode,and particle fragmentation characteristics were affected by the CSA,with the peak strain being greatest in sandstone samples subjected to the greatest CSA.With increasing CSA,the load-unload response ratio of sandstone under the last cyclic stage generally tends to increase.Furthermore,there was an increasing trend in the dissipated energy percentage of sandstone as the CSA increased,which was a result of the increased energy used to drive fracture extension.Moreover,the sandstone exhibited a tensile-shear composite failure mode dominated by shear failure.Nevertheless,with increasing CSA,the shear failure surface became more obvious.In addition,the proportion of small blocks and the fragmentation fractal dimension increased as the CSA increased,which indicated a high degree of fragmentation.Additionally,a sandstone damage constitu-tive model was developed to describe the results.Eventually,the macro-meso failure mechanism of sandstone considering CSA effects was revealed.Under high CSA,the internal fracture extension and particle friction of sandstone increased,which is the internal cause.The mechanical parameters indicated strong deformation and high dissipated energy characteristics,which is the external manifestation.This investigation is important for preventing the occurrence of disasters in underground engineering,such as coal mining.

摘要：The stability of slopes and tunnels is controlled by rock discontinuities,and the rock discontinuities roughness and the slid-ing direction play a significant role in shear failure.However,three-dimensional roughness evaluation considering shear directions is scare,and the internal shear fracturing processes,micromechanical mechanisms and failure precursor of rock discontinuities are not well understood.Therefore,this study proposes a novel roughness evaluation index to quantitatively analyze the anisotropic characteristics of rock discontinuities.In conjunction with shear tests,a novel 3D-GBM modelling method considering the micromineral constituent and particle size distribution characteristics of granite as well as the geo-metric shape of discontinuities was realized.The strength,macro and micro-fracture characteristics,visual anisotropic shear evolution process and microfailure mechanism of granite discontinuities at different roughness and shear direction were investigated.Finally,the spatial and temporal evolutions of AE parameter b-value and magnitude M were further analyzed to reveal the shear fracture precursor of granite discontinuities.

摘要：The regulation of catalytic pyrolysis products of coal tar(CT)is a great challenge due to its complex chemical composition and inter-component interactions.Herein,Fe-Ca/H-Si catalysts were prepared and used for catalytic pyrolysis of CT for upgrading quality by acid treatment and impregnation methods,and the effect of carrier crystal-linity on the distribution of CT pyrolysis products was investigated.The results showed that acid treatment disrupted the ordered crystals of silica(H-Si),creating more E'-centres defects as crystallinity decreased,and generating more sites for phenol removal reactions.The phenolic conversion of CT over H-Si increased by 12.42％at 700 ℃ during pyrolysis compared to SiO2.Meanwhile,the lower crystallinity of H-Si produced a larger free volume,providing sites for the anchoring of Fe and Ca.Fe facilitated the cleavage of C-C bonds and promoted the conversion of naphthalenes to aliphatic hydrocarbons.Additionally,CaO altered the electron distribution of compounds such as 2-ethyl-phenol and promoted their deoxygenation.Model compound experiments showed that the Fe-Ca/H-Si cata-lyst achieved 79.82％phenol conversion at 700 ℃,and also promoted the one-step deep reduction of naphthalene to 1-decene.These findings indicate that the Fe-Ca/H-Si catalyst offers a promising strategy for utilization of real CT.

摘要：The deposition of coal fines in fractures reduces fracture conductivity and hampers efficient coalbed methane production.The results of the multiphase flow visualization experiment indicate that,at low flow rates,fines primarily deposit at the bottom of fracture.At medium flow rates,they exhibit finger-like migration patterns.At high flow rates,some fines initially transported out,but later they tend to form agglomerates.Fine coal fines migrate through suspension and rolling,while medium coal fines form filter cakes both inside and outside the fractures,and coarse coal fines block gas-water flow by forming filter cakes at the fracture fronts.Smaller particle sizes result in higher fines production.The output of coal fines peaks at concentration 4％before declining.Higher concentrations promote the formation of filter cake;however,gas-water injection can effectively clear these blockages.Multiple forces drive fines migration,with capillary forces playing a significant role in this process.The initiation velocity decreases with increasing particle size,but it rises again at a particle size threshold of 22 μm.In the early stages,fines are more influenced by adhesion forces,but gravity prevails as particle size grows.At flow rates between 0.2 and 0.29 cm/s,fines ranging from 0.4 to 52.44 μm are discharged from the coal seam.The results provide insights into coalbed methane production during gas-water flow.

摘要：Lower Paleozoic black shales are important source rocks worldwide.The Upper Ordovician-Lower Silurian Renheqiao Formation of the Baoshan Block is a low-maturity equivalent of the Wufeng-Longmaxi(WF-LMX)Shale of the Sichuan Basin.However,organic matter(OM)characteristics in these low-maturity Lower Paleozoic shales are not well under-stood.In this study,50 Renheqiao Formation shale samples collected from seven outcrop sections and one drill core were investigated with organic petrology,organic geochemistry,Rock-Eval pyrolysis,N2 and CO2 adsorption,and scanning electron microscope(SEM)analyses to study the OM content,type,thermal maturity,and the development of OM-hosted pores in these Lower Paleozoic shales.The total organic carbon(TOC)content of the Renheqiao Formation shales varies,with the maximum content of 10.07 wt％.Rock-Eval pyrolysis results show that present OM in the Renheqiao Formation shales is Type Ⅳ kerogen,a result of advanced thermal maturation.Graptolite reflectance(GRo)ranges from 1.26％to 1.85％,and equivalent vitrinite reflectance(EqRo)converted from GRo ranges from 1.08％to 1.51％,indicating that the studied Renheqiao Formation shales are dominantly within the late-mature stage.EqRo based on Rock-Eval Tmax shows large variations,which indicates that Rock-Eval Tmax is not a reliable thermal maturity indicator for the Lower Paleozoic Renheqiao Formation shales.Caution should be applied when assessing the thermal maturity of high-maturity black shales based on Tmax when the S2 values are too low.Organic petrographic observations show that OM in these shales is domi-nated by solid bitumen(＞70 vol％of total OM),with minor contributions by graptolites and chitinozoans.The specific surface area and pore volume of shales are controlled by TOC content.Organic pores are hosted by solid bitumen and were not observed in graptolites when examined under the SEM.Although the Renheqiao Formation has a lower thermal maturity than the over-mature WF-LMX Shale,it is mature enough that primary oil-prone macerals have been thermally transformed and could not be identified under the microscope.

摘要：To explore the influence of stress space rotation on roadway stability,this study establishes Cartesian and principal stress axes,obtains principal stress characteristic parameters and direction cosine matrix,and determines the conversion process between coordinate axes.By breaking through the traditional plane strain mechanics model,a full plane strain model of rectangular roadway considering the deflection effect of principal stress axis is established.The analytical solution of stress complex variation of any element around the roadway is derived,and the calculation method of plastic zone is given.The influence of stress deflection on the stress of roadway and the shape distribution of plastic zone is discussed and the control system of roadway under the action of principal stress deflection in spatial region is established.The research results show that:(1)the shear stress and normal stress formed in the remote of the roadway during the stress rotation are in the same order of magnitude,and the plastic quantitative calculation of the roadway cannot simply consider the normal stress.(2)Stress deflection causes the distribution of stress and plastic zone around the roadway to show'asymmetric'failure characteristics,and the transient deflection of stress may cause the rapid expansion of the plastic zone of the roadway.(3)The distribution characteristics of plastic zone calculated by this study are compared with the deformation and failure feature and peep results of the return air roadway in Cuncaota Mine,and the comparison results are good.The supporting system and technology of roadway under the action of principal stress deflection in space area are put forward,and the field application effect is good.

摘要：Traditional fracturing fluids often face limitations in achieving a balance between viscosity,gel-breaking capability,and formation protection,which poses a significant challenge for the development of optimally performing fluids in mining applications.This study introduces a novel hydrophobic polymer/surfactant composite(HSC)fracturing fluids synthesized by cross-linking hydrophobically modified hydroxypropyl guar gum(HMHPG)with a gemini-surfactant amide-based bis-quaternary ammonium salt(GS-A6).The performance characteristics were evaluated through comparative analysis with conventional fracturing fluids,focusing on viscosity,gel-breaking properties,methane adsorption-desorption behavior,and effects on coal pore structures.The HSC fracturing fluids,comprising 0.2％HMHPG+0.8％GS-A6,demonstrated superior performance metrics.The viscosity achieved was three times higher than that of the 0.8％GS-A6 fracturing fluids,while the gel-breaking time was reduced by 50％compared to the 0.2％HPG fracturing fluids.The HSC fracturing fluids exhibited reduced impact on methane adsorption and desorption in coal samples,with a 24％lower adsorption damage factor compared to HPG fracturing fluids.Analysis of coal pore structures revealed a decrease in fractal dimension Di,indicating surface smoothing effects due to controlled plugging.The developed HSC fracturing fluids demonstrates significant improvements in key performance parameters while minimizing formation damage.These findings provide valuable insights for advanc-ing fracturing fluid technology in mining applications and contribute to the optimization of hydraulic fracturing operations.