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Research on the mechanism of rockburst induced by mined coal-rock linkage of sharply inclined coal seams
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作者 Xingping Lai Huicong Xu +4 位作者 Pengfei Shan Qinxin Hu Weixi Ding Shangtong Yang Zhongming Yan 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期929-942,共14页
In recent years,the mining depth of steeply inclined coal seams in the Urumqi mining area has gradually increased.Local deformation of mining coal-rock results in frequent rockbursts.This has become a critical issue t... In recent years,the mining depth of steeply inclined coal seams in the Urumqi mining area has gradually increased.Local deformation of mining coal-rock results in frequent rockbursts.This has become a critical issue that affects the safe mining of deep,steeply inclined coal seams.In this work,we adopt a perspective centered on localized deformation in coal-rock mining and systematically combine theoretical analyses and extensive data mining of voluminous microseismic data.We describe a mechanical model for the urgently inclined mining of both the sandwiched rock pillar and the roof,explaining the mechanical response behavior of key disaster-prone zones within the deep working face,affected by the dynamics of deep mining.By exploring the spatial correlation inherent in extensive microseismic data,we delineate the“time-space”response relationship that governs the dynamic failure of coal-rock during the progression of the sharply inclined working face.The results disclose that(1)the distinctive coal-rock occurrence structure characterized by a“sandwiched rock pillar-B6 roof”constitutes the origin of rockburst in the southern mining area of the Wudong Coal Mine,with both elements presenting different degrees of deformation localization with increasing mining depth.(2)As mining depth increases,the bending deformation and energy accumulation within the rock pillar and roof show nonlinear acceleration.The localized deformation of deep,steeply inclined coal-rock engenders the spatial superposition of squeezing and prying effects in both the strike and dip directions,increasing the energy distribution disparity and stress asymmetry of the“sandwiched rock pillar-B3+6 coal seam-B6 roof”configuration.This makes worse the propensity for frequent dynamic disasters in the working face.(3)The developed high-energy distortion zone“inner-outer”control technology effectively reduces high stress concentration and energy distortion in the surrounding rock.After implementation,the average apparent resistivity in the rock pillar and B6 roof substantially increased by 430%and 300%,respectively,thus guaranteeing the safe and efficient development of steeply inclined coal seams. 展开更多
关键词 steeply inclined coal seam localized deformation mechanism of induced rockburst prevention and control of rockburst
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Disasters of gas-coal spontaneous combustion in goaf of steeply inclined extra-thick coal seams 被引量:1
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作者 Qiming Zhang Enyuan Wang +2 位作者 Xiaojun Feng Shuxin Liu Dong Chen 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期4141-4153,共13页
In light of the escalating global energy imperatives,mining of challenging-to-access resources,such as steeply inclined extra-thick coal seams(SIEC),has emerged as one of the future trends within the domain of energy ... In light of the escalating global energy imperatives,mining of challenging-to-access resources,such as steeply inclined extra-thick coal seams(SIEC),has emerged as one of the future trends within the domain of energy advancement.However,there is a risk of gas and coal spontaneous combustion coupling disasters(GCC)within the goaf of SIEC due to the complex goaf structure engendered by the unique mining methodologies of SIEC.To ensure that SIEC is mined safely and efficiently,this study conducts research on the GCC within the goaf of SIEC using field observation,theoretical analysis,and numerical modeling.The results demonstrate that the dip angle,the structural dimensions in terms of width-to-length ratio,and compressive strength of the overlying rock are the key factors contributing to the goaf instability of SIEC.The gangue was asymmetrically filled,primarily accumulating within the central and lower portions of the goaf,and the filling height increased proportionally with the advancing caving height,the expansion coefficient,and the thickness of the surrounding rock formation.The GCC occurs in the goaf of SIEC,with an air-return side range of 41 m and an air-intake side range of 14 m,at the intersection area of the“<”-shaped oxygen concentration distribution(coal spontaneous combustion)and the“>”-shaped gas concentration distribution(gas explosion).The optimal nitrogen flow rate is 1000 m3/h with an injection port situated 25 m away from the working face for the highest nitrogen diffusion efficacy and lowest risk of gas explosion,coal spontaneous combustion,and GCC.It has significant engineering applications for ensuring the safe mining of SIEC threatened by the GCC. 展开更多
关键词 Steeply inclined extra-thick coal seams Gas explosion coal spontaneous combustion Coupling disaster Numerical simulation
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A hybrid ventilation scheme applied to bidirectional excavation tunnel construction with a long inclined shaft
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作者 YANG Wei-chao WANG Jian +3 位作者 DENG E LIU Yi-kang LUO Lu-sen YANG Jia 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第9期3187-3205,共19页
The breakage and bending of ducts result in a difficulty to cope with ventilation issues in bidirectional excavation tunnels with a long inclined shaft using a single ventilation method based on ducts.To discuss the h... The breakage and bending of ducts result in a difficulty to cope with ventilation issues in bidirectional excavation tunnels with a long inclined shaft using a single ventilation method based on ducts.To discuss the hybrid ventilation system applied in bidirectional excavation tunnels with a long inclined shaft,this study has established a full-scale computational fluid dynamics model based on field tests,the Poly-Hexcore method,and the sliding mesh technique.The distribution of wind speed,temperature field,and CO in the tunnel are taken as indices to compare the ventilation efficiency of three ventilation systems(duct,duct-ventilation shaft,duct–ventilated shaft-axial fan).The results show that the hybrid ventilation scheme based on duct-ventilation shaft–axial fan performs the best among the three ventilation systems.Compared to the duct,the wind speed and cooling rate in the tunnel are enhanced by 7.5%–30.6%and 14.1%–17.7%,respectively,for the duct-vent shaft-axial fan condition,and the volume fractions of CO are reduced by 26.9%–73.9%.This contributes to the effective design of combined ventilation for bidirectional excavation tunnels with an inclined shaft,ultimately improving the air quality within the tunnel. 展开更多
关键词 bidirectional excavation tunnel inclined shaft hybrid ventilation scheme computational fluid dynamics ventilation efficiency
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Evolution of a mining induced fracture network in the overburden strata of an inclined coal seam 被引量:8
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作者 Wei Xiujun Gao Mingzhong +3 位作者 Lv Youchang Shi Xiangchao Gao Hailian Zhou Hongwei 《International Journal of Mining Science and Technology》 SCIE EI 2012年第6期775-779,共5页
The geological conditions of the Pingdingshan coal mining group were used to construct a physical model used to study the distribution and evolution of mining induced cracks in the overburden strata.Digital graphics t... The geological conditions of the Pingdingshan coal mining group were used to construct a physical model used to study the distribution and evolution of mining induced cracks in the overburden strata.Digital graphics technology and fractal theory are introduced to characterize the distribution and growth of the mining induced fractures in the overburden strata of an inclined coal seam.A relationship between fractal dimension of the fracture network and the pressure in the overburden strata is suggested.Mining induced fractures spread dynamically to the mining face and up into the roof as the length of advance increases.Moreover,the fractal dimension of the fracture network increases with increased mining length,in general,but decreases during a period from overburden strata separation until the main roof collapses.It is a1so shown that overburden strata pressure plays an important role in the evolution of mining induced fractures and that the fractal dimension of the fractures increases with the pressure of the overburden. 展开更多
关键词 inclined coal SEAM Fracture network EVOLUTION FRACTAL DIMENSION
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Theoretical description of drawing body shape in an inclined seam with longwall top coal caving mining 被引量:8
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作者 Jiachen Wang Weijie Wei Jinwang Zhang 《International Journal of Coal Science & Technology》 EI 2020年第1期182-195,共14页
Understanding the characteristics of drawing body shape is essential for optimization of drawing parameters in longwall top coal caving mining.In this study,both physical experiments and theoretical analysis are emplo... Understanding the characteristics of drawing body shape is essential for optimization of drawing parameters in longwall top coal caving mining.In this study,both physical experiments and theoretical analysis are employed to investigate these characteristics and derive a theoretical equation for the drawing body shape along the working face in an inclined seam.By analyzing the initial positions of drawn marked particles,the characteristics of the drawing body shape for different seam dip angles are obtained.It is shown that the drawing body of the top coal exhibits a shape-difference and volume-symmetry characteristic,on taking a vertical line through the center of support opening as the axis of symmetry,the shapes of the drawing body on the two sides of this axis are clearly different,but their volumes are equal.By establishing theoretical models of the drawing body in the initial drawing stage and the normal drawing stage,a theoretical equation for the drawing body in an inclined seam is proposed,which can accurately describe the characteristics of the drawing body shape.The shape characteristics and volume symmetry of the drawing body are further analyzed by comparing the results of theoretical calculations and numerical simulations.It is shown that one side of the drawing body is divided into two parts by an inflection point,with the lower part being a variation development area.This variation development area increases gradually with increasing seam dip angle,resulting in an asymmetry of the drawing body shape.However,the volume symmetry coefficient fluctuates around 1 for all values of the seam dip angle variation,and the volumes of the drawing body on the two sides are more or less equal as the variation development volume is more or less equal to the cut volume.Both theoretical calculations and numerical simulations confirm that the drawing body of the top coal exhibits the shape-difference and volume-symmetry characteristic. 展开更多
关键词 Longwall top coal caving mining inclined seam Top coal Drawing body shape Equation for drawing body
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Study on stress distribution and failure criterion of the roof for the severely inclined coal seam under long wall working 被引量:1
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作者 MENG Xiang-rui GAO Zhao-ning WANG Xiang-qian 《Journal of Coal Science & Engineering(China)》 2012年第2期118-122,共5页
By turning to the theory of elastic thin plates, a mechanical model of the main roof breaking for severely inclined seam under long wall working was esbalished, in which formulaes were deduced for the calculation of t... By turning to the theory of elastic thin plates, a mechanical model of the main roof breaking for severely inclined seam under long wall working was esbalished, in which formulaes were deduced for the calculation of the stress distribution. When the main roof stress distribution was characterized, the failure form of the roof in the long wall coal seam under work was given with the failure criterion deduced. The deduced failure criterion was then applied to the No.3232(3) face of the Li- zuizi Coal Mine; the first pressure for the working face was accurately predicted. Results of the field application show that the main roof of the severely inclined coal seam under long wall working breaks in the O-X pattern, which is basically in accor- dance with the reality. 展开更多
关键词 stress distribution severely inclined coal seam failure criterion
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Short-term warning and integrity monitoring algorithm for coal mine shaft safety 被引量:3
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作者 王坚 谭兴龙 +1 位作者 韩厚增 T.B.AFENI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第11期3666-3673,共8页
A new short-term warning and integrity monitoring algorithm was proposed for coal mine shaft safety. The Kalman filter (KF) model was used to extract real global positioning system (GPS) kinematic deformation informat... A new short-term warning and integrity monitoring algorithm was proposed for coal mine shaft safety. The Kalman filter (KF) model was used to extract real global positioning system (GPS) kinematic deformation information. The short-term warning model was built by using the two-side cumulative sum (CUSUM) test, which further improves the warning system reliability. Availability (the minimum warning deformation, MWD), false alarm rate (the average run length, ARL), missed rate (the warning delay, WD) and the relationships among them were analyzed and the method choosing warning parameters is given. A test of a deformation simulation platform shows that the warning algorithm can be effectively used for steep deformation warning. A field experiment of the Malan mine shaft in Shanxi coal area illustrates that the proposed algorithm can detect small dynamic changes and the corresponding occurring time. At given warning thresholds (MWD is 15 mm and ARL is 1000),the detected deformations of two consecutive days’ deformation sequences with the algorithm occur at the 705th epoch (705 s) and the 517th epoch (517 s), respectively. 展开更多
关键词 coal mine shaft DEFORMATION cumulative sum short-term warning Kalman filter integrity monitoring
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Evaluation of pneumatic inclined deck separator for high-ash Indian coals 被引量:6
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作者 Nikhil Gupta 《International Journal of Coal Science & Technology》 EI 2016年第2期198-205,共8页
Application of pneumatic separators in coal beneficiation is increasing rapidly over the last decade primarily due to their low capital and operating costs, and waste handling problems associated with traditional wet ... Application of pneumatic separators in coal beneficiation is increasing rapidly over the last decade primarily due to their low capital and operating costs, and waste handling problems associated with traditional wet processing methods. Large amount of shale/rock that is extracted in coal production can be removed prior to transportation at the mine face by using this methodology. Due to the limited washing facilities in India, most of the thermal power plants burn raw coal from run-of-mine (ROM) to generate electricity. This practice causes poor utilization efficiency, high operating and maintenance costs, and high emission rates for the power plants. One potential method that can be utilized is the air-fluidized inclined vibrating deck technology. The technology was demonstrated on a pilot-scale at different coal washeries in India at a feed rate of 5-ton per hour. The pilot-scale evaluation showed that 20 %-25 % high-ash incombustible material can be eliminated from ROM feed with only minor losses in energy content (〈10 %) from respective ROM coal. Furthermore, a feasibility analysis showed significant economic gains in terms of transportation cost, improving power-plant efficiency, and reducing emissions rates by using the technology. 展开更多
关键词 coal deshaling Pneumatic separation inclined deck Vibrating table FLUIDIZATION
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Stability of roof structure and its control in steeply inclined coal seams 被引量:21
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作者 Li Xiaomeng Wang Zhaohui Zhang Jinwang 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第2期359-364,共6页
To improve the effectiveness of control of surrounding rock and the stability of supports on longwall topcoal caving faces in steeply inclined coal seams, the stability of the roof structure and hydraulic supports was... To improve the effectiveness of control of surrounding rock and the stability of supports on longwall topcoal caving faces in steeply inclined coal seams, the stability of the roof structure and hydraulic supports was studied with physical simulation and theoretical analysis. The results show that roof strata in the vicinity of the tail gate subside extensively with small cutting height, while roof subsidence near the main gate is relatively assuasive. With increase of the mining space, the caving angle of the roof strata above the main gate increases. The characteristics of the vertical and horizontal displacement of the roof strata demonstrate that caved blocks rotate around the lower hinged point of the roof structure, which may lead to sliding instability. Large dip angle of the coal seam makes sliding instability of the roof structure easier.A three-hinged arch can be easily formed above both the tail and main gates in steeply inclined coal seams. With the growth in the dip angle, subsidence of the arch foot formed above the main gate decreases significantly, which reduces the probability of the roof structure becoming unstable as a result of large deformation, while the potential of the roof structure's sliding instability above the tail gate increases dramatically. 展开更多
关键词 Steeply inclined coal seam inclined masonry structure Overlying strata Structure instability
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Analysis of stability of support and surrounding rock in mining top coa of inclined coal seam 被引量:8
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作者 Xin Yajun Gou Panfeng Ge Fudong 《International Journal of Mining Science and Technology》 SCIE EI 2014年第1期63-68,共6页
The study analyzes the characteristics of roof movement in mining top coal of inclined coal seam,and establishes the mechanical model of support and surrounding-rock stability in inclined coal seam.Besides,this study ... The study analyzes the characteristics of roof movement in mining top coal of inclined coal seam,and establishes the mechanical model of support and surrounding-rock stability in inclined coal seam.Besides,this study carries out the numerical calculation and field observation of roof movement and support stability,and provides the critical control measures.The results show that the fracture firstly appears in middle-upper roof and extends upwards in top coal caving in inclined coal seam;regular and irregular caving zones appear in middle-upper stress concentration region,and the asymmetric caving arch is finally formed.Support load of middle-upper working face is larger than that of the middle-lower face;dynamic load coefficient of upper support is large,and the load on the front of support is larger than that on the rear of it,which leads to poor support stability.Stability of support and surrounding-rock system depends mainly on upper-support stability. 展开更多
关键词 inclined coal seamRoof movement Mechanical modelStability
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Numerical simulation analysis of covering rock strata as mining steep-inclined coal seam under fault movement 被引量:6
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作者 MA Feng-hai, SUN Li, LI Dun College of Civil and Architectural Engineering, Dalian University, Dalian 116622, China 《中国有色金属学会会刊:英文版》 CSCD 2011年第S3期556-561,共6页
The fault is one important factor for the stability of overburden strata caused by steeply inclined coal seam. The stress and displacement change of overburden strata caused by steeply-inclined coal seam mining activi... The fault is one important factor for the stability of overburden strata caused by steeply inclined coal seam. The stress and displacement change of overburden strata caused by steeply-inclined coal seam mining activity under faulting was simulated by FLAC2D finite differential program on the basis of Zhaogezhuang mining example belonging to Kailuan Mining Group. From the results, the stress and displacement clouding image after mining became complex because of the fault, that is, a kind of weak structural plane. The stress concentration region concentrated around the goaf, and also around the fault plane. As the mining depth increases, the stress and displacement within the fault zone change significantly. This movement and deformation characteristic of overburden strata can provide theoretical basis for the similar mining condition. 展开更多
关键词 FAULT steep-inclined coal SEAM numerical simulation OVERBURDEN DISTORTION
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Fundamental Study on New Method of Reducing Iron Ore-Coal Pellet in Cocurrent Shaft Furnace 被引量:1
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作者 Wang Qi Yang Zhaoxiang +2 位作者 Tian Jimin Li Wenzhong Sun Jiafu 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 1999年第1期19-22,共4页
Based on the laboratory experiment of reducing iron ore-coal pellet in oxidizing atmosphere,a new self-heating reduction method of iron ore-coal pellet in the cocurrent shaft furnace(CSF) has been developed.In this pr... Based on the laboratory experiment of reducing iron ore-coal pellet in oxidizing atmosphere,a new self-heating reduction method of iron ore-coal pellet in the cocurrent shaft furnace(CSF) has been developed.In this process,the pellets and preheated oxygen-enriched air enter the shaft furnace through its top and descend cocurrently in the furnace.Most of the heat required for rising temperature and endothermic reduction of descending pellets is provided by the way that the descending air burns the volatile from pellets and CO from the reduction of iron oxide in pellets.The reduced pellets and high temperature gas are discharged from the lower part.The sensible heat and chemical energy of the off-gas are used to heat the oxygen-enriched air in stove.This process is applicable to the direct reduction of iron pellets and prereduction of iron pellets in smelting reduction with iron bath. 展开更多
关键词 iron ore-coal pellet cocurrent shaft furnace REDUCTION
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Stability analysis and control technology of gob‑side entry retaining with double roadways by flling with high‑water material in gently inclined coal seam
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作者 Shengrong Xie En Wang +3 位作者 Dongdong Chen Hui Li Zaisheng Jiang Hongzeng Yang 《International Journal of Coal Science & Technology》 EI CAS CSCD 2022年第4期147-164,共18页
To ameliorate the defects of insufcient support resistance of traditional roadside flling bodies for gob-side entry retaining(GER),overcome the inability to adapt to the deformation of surrounding rock,and isolate the... To ameliorate the defects of insufcient support resistance of traditional roadside flling bodies for gob-side entry retaining(GER),overcome the inability to adapt to the deformation of surrounding rock,and isolate the goaf efectively,a new type of high-water material as a roadside flling body for GER technology with double roadways was proposed.The instability analysis and control technology of GER with double roadways by flling high-water material into a gently inclined coal seam were studied.The basic mechanical properties of the new high-water material were investigated through laboratory experiments,and their main advantages were identifed.The reasonable width of the roadside flling wall of a high-water material was obtained by combining ground pressure observation and theoretical calculations.The distribution characteristics of the stress and plastic zone of surrounding rock of GER after being stabilized by the disturbance of the working face were studied using numerical simulations,and the failure range of GER by flling with high-water material was revealed.Based on this,a coupling control technology of anchor cables and bolts+single props+metal mesh+anchor bolts is proposed.Through the coupling methods of arranging borehole peeping and observing the convergences of surrounding rock,the results demonstrate that GER with double roadways by flling with a 1.8-m-wide high-water material has a good control efect.The above research will play an active role in promoting the application of high-water materials in GER roadside flling. 展开更多
关键词 High-water material Gob-side entry retaining with double roadways Stability analysis Gently inclined coal seam Control technology
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Study on Supporting of Seam Roadways in Deeply Inclined Coal Seams 被引量:2
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作者 Luo Yong Shen Zhaowu +1 位作者 Xie Guangxiang Liu Quanming 《工程科学(英文版)》 2006年第1期45-51,共7页
Based on the present problems of the support method of gateways in complex surrounding rock in steeply inclined seams, this paper discusses the support selection of lasting gateways in steeply inclined seams, and eval... Based on the present problems of the support method of gateways in complex surrounding rock in steeply inclined seams, this paper discusses the support selection of lasting gateways in steeply inclined seams, and evaluates the support effects. It draws the conclusion that the support of bolt-mesh-anchor is the most effective support of this sort of gateways by using scale model simulation in lab and practice application.The support effects of practice application are satisfactory. It will give a beneficial reference to other analogical mine and has an extensive application prospect. 展开更多
关键词 倾斜煤层 比例模型 路面裂缝 矿井支护 锚杆
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Development and prospect on fully mechanized mining in Chinese coal mines 被引量:104
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作者 Jinhua Wang 《International Journal of Coal Science & Technology》 EI CAS 2014年第3期253-260,共8页
Fully mechanized mining(FMM)technology has been applied in Chinese coal mines for more than 40 years.At present,the output of a FMM face has reached 10-million tons with Chinese-made equipment.In this study,the new de... Fully mechanized mining(FMM)technology has been applied in Chinese coal mines for more than 40 years.At present,the output of a FMM face has reached 10-million tons with Chinese-made equipment.In this study,the new developments in FMM technology and equipment in Chinese coal mines during past decades are introduced.The automatic FMM technology for thin seams,complete sets of FMM technology with ultra large shear height of 7 m for thick seams,complete sets of fully mechanized top coal caving technology with large shear height for ultra-thick seams of 20 m,complete sets of FMM technology for complex and difficult seams,including steeply inclined seams,soft coal seams with large inclination angle,and the mechanized filling mining technology and equipment are presented.Some typical case studies are also introduced.Finally,the existing problems with the FMM technology are discussed,and prospect of FMM technology and equipment applied in Chinese coal mines is put forward. 展开更多
关键词 Fully mechanized mining Mining with large shear height Fully mechanized top coal caving Steeply inclined seam Back filling mining PROSPECT
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An improved influence function method for predicting subsidence caused by longwall mining operations in inclined coal seams 被引量:10
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作者 Yi Luo 《International Journal of Coal Science & Technology》 EI 2015年第3期163-169,共7页
Prediction of surface subsidence caused by longwall mining operation in inclined coal seams is often very challenging. The existing empirical prediction methods are inflexible for varying geological and mining conditi... Prediction of surface subsidence caused by longwall mining operation in inclined coal seams is often very challenging. The existing empirical prediction methods are inflexible for varying geological and mining conditions. An improved influence function method has been developed to take the advantage of its fundamentally sound nature and flexibility. In developing this method, the original Knothe function has been transformed to produce a continuous and asymmetrical subsidence influence function. The empirical equations for final subsidence parameters derived from col- lected longwall subsidence data have been incorporated into the mathematical models to improve the prediction accuracy. A number of demonstration cases for longwall mining operations in coal seams with varying inclination angles, depths and panel widths have been used to verify the applicability of the new subsidence prediction model. 展开更多
关键词 Subsidence prediction Influence function method inclined coal seam Longwall mining
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An influence function method based subsidence prediction program for longwall mining operations in inclined coal seams 被引量:12
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作者 LUO Yi CHENG Jian-wei 《Mining Science and Technology》 EI CAS 2009年第5期592-598,共7页
The distribution of the final surface subsidence basin induced by longwall operations in inclined coal seam could be significantly different from that in flat coal seam and demands special prediction methods. Though m... The distribution of the final surface subsidence basin induced by longwall operations in inclined coal seam could be significantly different from that in flat coal seam and demands special prediction methods. Though many empirical prediction methods have been developed, these methods are inflexible for varying geological and mining conditions. An influence function method has been developed to take the advantage of its fundamentally sound nature and flexibility. In developing this method, significant modifications have been made to the original Knothe function to produce an asymmetrical influence function. The empirical equations for final subsidence parameters derived from US subsidence data and Chinese empirical values have been incorpo- rated into the mathematical models to improve the prediction accuracy. A corresponding computer program is developed. A number of subsidence cases for longwall mining operations in coal seams with varying inclination angles have been used to demonstrate the applicability of the developed subsidence prediction model. 展开更多
关键词 subsidence prediction influence function method inclined coal seam longwall mining
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Cavitating Propeller Performance in Inclined Shaft Conditions with OpenFOAM:PPTC 2015 Test Case 被引量:2
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作者 Stefano Gaggero Diego Villa 《Journal of Marine Science and Application》 CSCD 2018年第1期1-20,共20页
In this paper,we present our analysis of the non-cavitating and cavitating unsteady performances of the Potsdam Propeller Test Case(PPTC)in oblique flow.For our calculations,we used the Reynolds-averaged Navier-Stokes... In this paper,we present our analysis of the non-cavitating and cavitating unsteady performances of the Potsdam Propeller Test Case(PPTC)in oblique flow.For our calculations,we used the Reynolds-averaged Navier-Stokes equation(RANSE)solver from the open-source OpenFOAM libraries.We selected the homogeneous mixture approach to solve for multiphase flow with phase change,using the volume of fluid(VoF)approach to solve the multiphase flow and modeling the mass transfer between vapor and water with the Schnerr-Sauer model.Comparing the model results with the experimental measurements collected during the SecondWorkshop on Cavitation and Propeller Performance– SMP’15 enabled our assessment of the reliability of the open-source calculations.Comparisons with the numerical data collected during the workshop enabled further analysis of the reliability of different flow solvers from which we produced an overview of recommended guidelines(mesh arrangements and solver setups)for accurate numerical prediction even in off-design conditions.Lastly,we propose a number of calculations using the boundary element method developed at the University of Genoa for assessing the reliability of this dated but still widely adopted approach for design and optimization in the preliminary stages of very demanding test cases. 展开更多
关键词 PROPELLER CAVITATION OPENFOAM RANSE BEM Unsteady flow PPTC inclined shaft
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Determining areas in an inclined coal seam floor prone to water-inrush by micro-seismic monitoring 被引量:11
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作者 Sun Jian Wang Lianguo +2 位作者 Wang Zhansheng Hou Huaqiang Shen Yifeng 《Mining Science and Technology》 EI CAS 2011年第2期165-168,共4页
The failure depth of the coal seam floor is one important consideration that must be kept in mind when mining is carried out above a confined aquifer.Determining the floor failure depth is the essential precondition f... The failure depth of the coal seam floor is one important consideration that must be kept in mind when mining is carried out above a confined aquifer.Determining the floor failure depth is the essential precondition for predicting the water-resisting ability of the floor.We have used a high-precision microseismic monitoring technique to overcome the limited amount of data available from field measurements. The failure depth of a coal seam floor,especially an inclined coal seam floor,may be more accurately estimated by monitoring the continuous,dynamic failure of the floor.The monitoring results indicate the failure depth of the coal seam floor near the workface conveyance roadway(the lower crossheading) is deeper and that the failure range is wider here compared to the coal seam floor near the return airway(the upper crossheading).The results of micro-seismic monitoring show that the dangerous area for water-inrush from the coal seam floor may be identified.This provides an important field measurement that helps ensure safe and highly efficient mining of the inclined coal seam above the confined aquifer at the Taoyuan Coal Mine. 展开更多
关键词 inclined coal seam Water-inrush from floor Dangerous area Micro-seismic monitoring
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Properties of New Mullite-SiC Bricks for CDQ Shafts 被引量:2
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作者 MA Shulong WEI Yingfeng +3 位作者 WANG Zhifeng MA Fei XIA Wenbin ZHOU Xiaowei 《China's Refractories》 CAS 2017年第1期47-50,共4页
Currently the service life of CDQ shafts in China is mainly restricted by the properties of the inclined flue bricks.In this work,based on the systematic analysis of the damage mechanism of inclined flue refractories,... Currently the service life of CDQ shafts in China is mainly restricted by the properties of the inclined flue bricks.In this work,based on the systematic analysis of the damage mechanism of inclined flue refractories,high performance mullite-SiC bricks were developed.The bricks were produced by corundum,andalusite,SiC and other high purity raw materials.Metal silicon and alumina ultra micropowder were added to form dispersion multi-phase structure,fortifying the matrix and improving the microstructure.The products have excellent properties such as low porosity,high density,good wear resistance,high refractoriness under load,and good thermal shock resistance.The products can replace the ordinary mullite-SiC bricks and obtain a good service life. 展开更多
关键词 CDQ shaft inclined flue new mullite -SiC bricks
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