Search

Copyright of China Mining Magazine is the property of China Mining Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Construction Technology is the property of Railway Construction Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In view of the challenges posed by the goaf at the pile tip to the design of rock-socketed piles (such as load-bearing performance and long-term service performance), a scaled model test was conducted using the rock-socketed piles in the goaf of the Dujiashan Super Bridge as a prototype. A scaled model test was conducted to study the bearing capacity of single pile at different distances from the goaf to the pile tip and whether the goaf was grouted or not. The scaled parameters were calculated and appropriate test materials were selected for model construction. Through multi-level load tests, the changing characteristics of pile top settlement, pile axial force, pile tip resistance and pile side friction at different distances from the goaf to the pile tip and after grouting were obtained. And the bearing characteristics of rock-socketed piles without goaf were comparatively analyzed. The results show that as the distance from the goaf to the pile tip decreases, the bearing capacity of the model pile tip bearing layer decreases, which is not conducive to the bearing capacity of the model pile. After grouting, the bearing capacity of the pile tip bearing layer is significantly increased, resulting in a significant reduction in pile top settlement of the model pile and a significant increase in bearing capacity. [ABSTRACT FROM AUTHOR]

To explore the impact of the goaf formed by steep coal mining on the safe operation of the overlying gas transmission pipeline, a three-dimensional numerical model was established for the goaf of a coal seam based on FLAC 3D software. The characteristics of geological settlement and pipeline displacement for the actual coal mine goaf were explored. In addition, the impact of steep coal seams with different dip angles and mining depths on the deformation of the overlying gas transmission pipeline was also studied. The results show that an collapse area above the coal seam slope with the largest depth of 1. 54 m is formed after mining for 100 m to the five steep coal seams in the coal mine area. The soil and rock in the collapse area mainly move horizontally and vertically downward towards the coal seam. The vertical displacement of the pipeline near the goaf is greater than the horizontal displacement, while the horizontal displacement of the pipeline far away from the goaf is greater. With the decrease of dip angle of steep seam and the increase of mining depth, the downward settlement of the pipeline increases significantly, and the position where the maximum settlement occurs gradually approaches the direction of the seam. [ABSTRACT FROM AUTHOR]

Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A three-dimensional geological model integrating real ground topography, ore bodies, and tunnels was established by 3Dmine and UAV. Combined with Rhino6-FLAC3D, a numerical calculation model for ore body extraction was developed. The impact of rock movement and surface deformation was simulated and analyzed. The effectiveness of simulation results was verified through InSAR monitoring. The results indicate that the simulation results are consistent with InSAR monitoring, indicating that the research method combining monitoring and simulation is effective. For the goaf left by open-pit mining, dry filling can limit the damage of surrounding rock and filling body. The stability of shallow filled mining areas might be affected by deep operations in the mining area, and there is a negative correlation between the severity of disturbance and the distance from deep work areas. According to InSAR monitoring and numerical simulation, the impact of goaf destruction and mining disturbance on the surface subsidence is weak. [ABSTRACT FROM AUTHOR]

The geological conditions of the karst terrace of synclinore are complicated. Geological disasters such as water inrush and mud outburst often occur when the tunnel crosses it. The Anping Tunnel was taken as an example. In the early stage of the design of the tunnel route, from the geological perspective, five main geological problems and possible geological disaster risks within the scope of the tunnel route were analyzed and evaluated one by one. And the concept of geological route selection of avoidance without disturbance was used. The route avoidance scheme was selected according to the evaluation results and the horizontal and vertical design indicators were determined. The research results have certain reference significance for geological route selection and route design of tunnels on the karst terrace under similar complicated geological conditions. [ABSTRACT FROM AUTHOR]

Copyright of Railway Construction Technology is the property of Railway Construction Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nonferrous Metals (Mining Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Construction Technology is the property of Railway Construction Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Investigation & Surveying is the property of Railway Investigation & Surveying Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Investigation & Surveying is the property of Railway Investigation & Surveying Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of CT Theory & Applications is the property of Editorial Department of CT Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Engineering Geology / Gongcheng Dizhi Xuebao is the property of Journal of Engineering Geology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Roof caving is one of the important hazard sources of underground goaf accidents. In order to study the air impact disaster caused by large-scale roof caving and the protective effect of overburden, taking the goaf of Dunde iron - zinc mine as the engineering background, using comprehensive research methods such as theoretical analysis and numerical simulation, the air impact disaster in goaf is theoretically calculated according to the actual mining conditions on site, and the roof caving in goaf is simulated and analyzed in combination with fluid mechanics numerical software. The results show that the numerical simulation can better show the diffusion behavior of air impact airflow in goaf under different working conditions. When there is no ore overburden, the maximum wind speed and maximum dynamic pressure of impact air flow in the ore-drawing roadway can reach 482. 6 mis and 602 142 Pa; when there is a 30-meterthick ore overburden, the maximum wind speed in the ore-drawing roadway is only 2. 71 mis and the maximum dynamic pressure is only 8. 03 Pa. In actual production, it is recommended to reserve a sufficient thickness of ore overburden to effectively protect the safety of personnel and equipment. [ABSTRACT FROM AUTHOR]

Copyright of World Nuclear Geoscience is the property of World Nuclear Geoscience Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to analyze the influence of the occurrence state of the goaf on the slope stability, aiming at the actual case of landslide caused by the underground goaf in the coal mine in Toutun Village, Zhenxiong County, Yunnan Province, combined with the orthogonal experimental design and the MIDAS GTS / NX numerical model, Based on the idea of sensitivity analysis, analyze the stress field, displacement field and the distribution law of the effective plastic zone of the slope, study the sensitivity of the influence of 3 levels of 4 factors such as the mining depth factor of goaf, the height factor of the goaf, the span of the goaf and the horizontal distance from the goaf to the slope. The research shows that: the mining depth factor of goaf is an important factor affecting the stability of the goaf, followed by the horizontal distance from the goaf to the slope, the span of the goaf, and the height factor of the goaf is the least influential. According to the goaf shape and the weight of the existing state elements, using the multiple linear regression equation, the limit state equation of the goaf's influence on the neighboring slope is obtained. The research results can be used for the stability analysis of the similar goaf slope to provide reference. [ABSTRACT FROM AUTHOR]

A gold mine, operating with the short-hole shrinkage method for a long time, leaves a large number of goafs. According to the steady state of the current goaf, 12 factors including uniaxial compressive strength, integrity coefficient, the exposed area of goafs, and span/height ratio were selected as the predictive index system, and the unascertained measurement model was constructed. A weight calculation method based on AHP-information entropy combination weighting is proposed, and the expert scoring method and linear formula method are used as the measurement function of the qualitative index and quantitative index, finally, the evaluation results are obtained according to the confidence recognition criterion. The research shows that the prediction results are consistent with the actual performance of the onsite goafs, verifying the feasibility of this method and diversifying the safety assessment method of goafs. [ABSTRACT FROM AUTHOR]

To evaluate the residual coal spontaneous combustion risk in goaf, the risk evaluation model was built for residual coal spontaneous combustion in goaf. In this model, the single index measure matrix was obtained based on the unascertained measures. The combination weight, including subjective and objective factors, was calculated by improved G1 method, improved CRITIC method and sum of deviation square maximizing. The comprehensive measure vectors of evaluation objects were determined by the combination weight and single index measure matrices. The risk rating and ranking of evaluation objects were judged by introducing confidence and rating assignment. Combined with the established model, the risk evaluation index system of residual coal spontaneous combustion in goaf was established from five aspects. The unascertained measure distribution functions of indexes were determined. The combination weight of evaluation indexes and comprehensive measure vectors of evaluation objects were calculated. The risk rating and ranking of residual coal spontaneous combustion in four goafs were judged by the confidence and rating assignment. The analysis of evaluation results shows that the risk rating and ranking of evaluation objects are in line with the actual condition. The evaluation results have a guiding function for coal mine fire prevention and extinguishing. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mining & Metallurgy (10057854) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Accurate understanding of the three-dimensional (3D) morphology of a complex goaf and its relative displacement in space is a precondition to further analyzing the stability of the cavity. Taking a uranium mining area in Ganzhou of China National Nuclear Corporation as the background, the BLSS-PE mining 3D laser scanning measurement system was used to explore and analyze the 3D spatial morphology of a goaf. The obtained data were digitally converted. Thereafter, the 3D spatial model of the goaf was established using DIMINE and it was digitally processed to achieve seamless coupling with the FLAC3D model, thus forming a 3D numerical computing model. The results show that the maximum principal stress in the 818-2# goaf increases after excavation. In addition, the maximum value appears in the top and bottom plate of the goaf, and the minimum stress remains nearly unchanged. The tensile stress appears in the upper and lower plates, but it is lower than that of the surrounding rock. The maximum horizontal and vertical displacements of the 818-2# goaf are small. The plastic zone appears in the surrounding rock of the goaf as the mining work progresses, but the area is small. It is concluded that the goaf is relatively stable overall. The research results may provide a strong reference for ground pressure management in mines and comprehensive control of goaves. [ABSTRACT FROM AUTHOR]

The goaf is an important factor affecting the slope stability of open-pit mines and safe mining.In mining, the goaf may be in the water-filling state, which may affect the stability of the open-pit slope.Therefore, taking the slope of an open-pit mine with water-filling goaf as the research background, this study analyzes the influence of the goaf presence and different water-filling states on slope stability through numerical calculation.The results show that the presence of the goaf may affect the local seepage field of the open-pit slope, causing stress concentration around the goaf, thereby changing the potential sliding surface and reducing the slope stability.The water filling in the goaf may lead to the generation of a local high water head, and make the stress around the goaf more concentrated so that the displacement of the slope is increased and the slope stability is reduced.With the increase of water filling degree in goaf, the safety coefficient of the slope decreases, and the influence of the goaf on the slope stability is more significant. [ABSTRACT FROM AUTHOR]

Copyright of Railway Investigation & Surveying is the property of Railway Investigation & Surveying Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The goaf is one of the main disaster risk sources faced by the construction of metal mines. Accurately prospecting the distribution characteristics of the goaf is an important support to ensure the safety of the mine construction. In order to ascertain the distribution of the goaf in front of the Gongchangling Iron Mine and Yanqianshan iron mine, which belong to Ansteel Group, the seismic ahead-prospecting method was used for long-distance detection. Through the extraction of the seismic reflection wave and the migration imaging processing, the distribution of the goaf within 120 m in front of the roadway is obtained. The detection results show the ellipsoidal goaf area in front of the 54 m deep roadway in the blind inclined shaft of Gongchangling iron mine and the mine pressure-induced goaf in front of the main slope at the 22 ~ 30 m depth in the Zhongci mining area of Yanqianshan iron mine, which provide safety support for construction. On this basis, numerical simulation and analysis were carried out for the non-flat side wall of Gongchangling iron mine roadway. The results reveal the influence characteristics of the scattered wave field generated by the non-flat side wall and the interpretation of the goaf detection results is further optimized. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Investigation & Surveying is the property of Railway Investigation & Surveying Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the problem of gas overrun at No.31102 working face in Cuncaota No.2 Mine, a comprehensive control was adopted by combining the adjustment of the air supply of the working face and the gas extraction of the buried pipe in the tail roadway. By establishing a fluid-chemical-thermal multi-field coupling mathematical equation and using COMSOL software to simulate the gas control process, the hazard law of multi-field coupling in goaf was obtained. The research results show that the air volume of the working face increases, the high gas area of the goaf moves toward the back of the goaf, and the gas volume fraction of the working face decreases. The air volume of working face is 1 174 m³/min as the basic air volume. When the ratio is increased to 1.25, the gas volume fraction at the corner of the working face is reduced to 0.24%, the high temperature area of the goaf has a certain hysteresis relative to the range of the oxidation zone, the drainage flow rate of the buried pipe gas drainage increases, and the goaf is oxidized. The width of the belt also gradually increased, and finally the extraction flow rate was 60 m³/min, the width of the oxidation belt was 295 m, and the gas at the corner of the working face was reduced to 0.16%. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mining Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to prevent spontaneous combustion in the goaf of the ZF1801 working face in the lower layer of the Xiagou coal mine, the oxygen volume fraction and air leakage speed at the actual air supply of the working face at 1 026 m³/min were monitored on site. According to the "three zones" division standard of coal spontaneous combustion in goafs and numerical simulation method, the dynamic changes of the spontaneous combustion zone in the goaf of the stratified ZF1801 face were studied by using Fluent software, then the range of spontaneous combustion zone was determined, and the fitting curve of spontaneous combustion zone in goaf was obtained. Finally, the combined fire prevention and extinguishing technology of "plugging and reducing oxygen-inert replacement" was put forward. The results show that the numerical simulation of the spontaneous combustion "three zones" fits well with the on-site monitoring, and the numerical simulation is reliable. The oxidation heating zone is 40~150 m on the inlet side of the goaf and 35~130 m in the middle. When the distance between air flow separation walls in goaf is 50m and the distance between nitrogen injection through sieve tube is kept at 40 m, the extinguishing effect is better, the maximum width of the oxidation heating zone of air flow separation wall is reduced from 110m to 80 m, and the maximum width of the oxidation heating zone of nitrogen injection through sieve tube is reduced from 110 m to 25 m. With on-site application of a combination of air flow separation wall and nitrogen injection through sieve tube to prevent and extinguish the fire, the CO volume fraction of the air return tunnel side bundle tube in the lower layer goaf is reduced from 476×10-6 to 32×10-6, and the upper corner CO volume fraction is reduced from 300×10-6 to 11×10-6. In the upper layer goaf, the CO volume fraction in the goaf above the transport roadway side was reduced from 700×10-6 to 37×10-6, and the air return tunnel side was reduced from 528×10-6 to 19×10-6. The treatment effect is remarkable. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mining Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Engineering Geology / Gongcheng Dizhi Xuebao is the property of Journal of Engineering Geology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Geological Hazard & Control is the property of China Institute of Geological Environmental Monitoring (CIGEM) Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to solve the problem of early warning and prevention of spontaneous combustion of coal pillar in long strike working face of Hongqingliang coal mine, aiming at the complex geological mining conditions of 11301 working face and the easy spontaneous combustion of coal pillar in surrounding roadway, SF6 gas measurement and fluent software numerical simulation were used to reveal the spontaneous combustion gas migration law and air leakage path of coal pillar in 11302 newly excavated return air roadway. The results show that the main cause of spontaneous combustion of coal pillar is the air leakage of coal pillar cracks between 11302 newly excavated return air roadway and 11301 working face; the spontaneous combustion gas of coal pillar in 11302 newly excavated return air roadway flows into 11302 old return air roadway through coal pillar fracture, and then reaches 11301 goaf through return air connecting roadway of 11301 working face. [ABSTRACT FROM AUTHOR]

Copyright of Mining & Metallurgy (10057854) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)