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2020

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Full-Text Articles in Mining Engineering

Waveform Cross Correlation-Based Imaging Of Underground Seismic Data While Mining, Zhang Huanlan, Wang Baoli Aug 2020

Waveform Cross Correlation-Based Imaging Of Underground Seismic Data While Mining, Zhang Huanlan, Wang Baoli

Coal Geology & Exploration

Seismics while mining is a passive seismic detection technique using a shearer as seismic source. Because the shearer moves unceasingly and excites the continuous signals, the conventional data processing method cannot be applied directly. In the paper a cross-correlation method of segmented waveform was put forward, the effective signal travel time was extracted through the segmentation of the data generated the shear, and then the velocity imaging method was used to image the interior of the working face and the front of the cutting hole. The wave equation was used to carry out the seismics while mining numerical simulation of …


Multi Frequency Perspective Fine Detection Of Radio Wave For Thin Coal Areas In Fully Mechanized Coal Face, Wu Rongxin, Shen Guoqing, Wang Hanqing, Xiao Yulin Aug 2020

Multi Frequency Perspective Fine Detection Of Radio Wave For Thin Coal Areas In Fully Mechanized Coal Face, Wu Rongxin, Shen Guoqing, Wang Hanqing, Xiao Yulin

Coal Geology & Exploration

The large area of thin coal area in the fully mechanized coal mining face is difficult to be detected accurately by the single frequency perspective detection of radio wave, which seriously affects the efficient and safe production of coal face. In order to detect the occurrence of thin coal area more precisely, a method of multi frequency perspective detection of radio wave is put forward. Taking coalface 1610A of Zhangji mine of Huaihe Energy Group as the research object, according to the geological conditions, four frequency(0.088, 0.158, 0.365 and 0.965 MHz) perspective detection are selected to delineate the thin coal …


Application Of Borehole Transient Electromagnetic Detection In The Test Of Hydraulic Fracturing Effect, Zhao Rui, Fan Tao, Li Yuteng, Wang Jikuang, Ma Yuan, Wang Bingchun, Liu Lei, Fang Zhe Aug 2020

Application Of Borehole Transient Electromagnetic Detection In The Test Of Hydraulic Fracturing Effect, Zhao Rui, Fan Tao, Li Yuteng, Wang Jikuang, Ma Yuan, Wang Bingchun, Liu Lei, Fang Zhe

Coal Geology & Exploration

Hydraulic fracturing technology is widely used in various aspects such as mine rock burst prevention and surrounding rock depressurization, but there has been a lack of efficient and intuitive technology for evaluating the fracturing effectiveness. To solve this problem, a three-component borehole TEM detection method using dynamic source and reception unit was proposed, and detection equipment and supporting construction techniques suitable for construction in hydraulic fracturing holes were developed. Two engineering tests have been carried out in a coal mine. By comparing the processing results of the vertical components of the two detection data before and after fracturing, a pure …


Development And Application Of Lightweight Underground Drill Rig, Fan Dong, Wang Ruize, Tian Hongliang, Chang Jianghua Aug 2020

Development And Application Of Lightweight Underground Drill Rig, Fan Dong, Wang Ruize, Tian Hongliang, Chang Jianghua

Coal Geology & Exploration

The underground drill rig is too heavy, so it is difficult to move and transport in the roadway with poor conditions. In order to solve the problem, ZDY1200G lightweight underground drill rig with 5052-h38 state high strength aluminum alloy as the main material is developed. The idea of light structure design and modular assembly is adopted, combined with the application of light materials. The maximum weight of single component after quick disassembly of the drill rig is 292.5 kg. The three-dimensional DIC speckle system was used to measure and analyze the strain and displacement of the aluminum alloy feed body …


Summary Of Water Disaster Characteristics And Water Prevention And Control Technology In Open-Pit Coal Mines In China, Huang Xuanming, Zhang Yan, Li Wensong, Tian Zenglin Aug 2020

Summary Of Water Disaster Characteristics And Water Prevention And Control Technology In Open-Pit Coal Mines In China, Huang Xuanming, Zhang Yan, Li Wensong, Tian Zenglin

Coal Geology & Exploration

Opencast mining is one of the two ways of coal mining in China. Similar to the underground coal mine, the open-pit coal mine also faces the problem of water prevention and control in the process of mining. Due to the relatively single type of water disaster in open-pit coal mines in China, domestic scholars have conducted in-depth study on the characteristics of water disaster and water control technology. Based on the distribution of open-pit coal mines in China, this paper analyzes the characteristics of water hazards in open-pit coal mines from three aspects of water filling source, water filling channel …


Construction Technology Of Vertical Concealed Laying Of Anti-Seepage Membrane For Water Cutoff Curtain In The Open-Pit Coal Mine, Li Wensong, Dang Yakun, Zhu Mingcheng, Gao Ya Aug 2020

Construction Technology Of Vertical Concealed Laying Of Anti-Seepage Membrane For Water Cutoff Curtain In The Open-Pit Coal Mine, Li Wensong, Dang Yakun, Zhu Mingcheng, Gao Ya

Coal Geology & Exploration

Anti-seepage membrane(HDPE geomembrane) is widely used in anti-seepage projects currently that mainly prevent pollution, leakage and diffusion, and its laying form was various. In an underground water cutoff curtain project of an open-pit coal mine in China, the anti-seepage membrane was laid vertically as the main body of the water cutoff curtain wall, and the largest concealed depth was about 50 m. The different groove sections was overlapping connected by using connection box technology. Through the grouting and backfilling process, the impermeability of the curtain wall was improved and the anti-seepage membrane was compacted. Finally, pumping test in the surrounding …


Technology Of High Pressure Jet Grouting Water Cutoff Curtain In Gravel Aquifer, Zhu Mingcheng, Han Qiang, Zhao Guibin, Liu Yuzhu Aug 2020

Technology Of High Pressure Jet Grouting Water Cutoff Curtain In Gravel Aquifer, Zhu Mingcheng, Han Qiang, Zhao Guibin, Liu Yuzhu

Coal Geology & Exploration

The high-pressure jet grouting pile is mainly suitable for the muddy soil, cohesive soil, silt, sand, loess and gravelly soil, but it is seldom used in the gravel stratum or under the dynamic water condition. A water cutoff certain in an open-pit coal mine was constructed by using RJP method, and the high pressure jet grouting technique was successfully applied to gravel aquifer. Based on the pile test and screening test, the influence of gravel layer characteristics on the size of pile diameter was analyzed. The results show that the RJP method had good effect and reliable quality in the …


Properties Of The Occluded Pile Curtain Material Under Low Temperature And Dynamic Water Condition In Deep And Thick Gravel Layer, Peng Wei, Wang Hai, Wang Zhongquan, Bu Guiling Aug 2020

Properties Of The Occluded Pile Curtain Material Under Low Temperature And Dynamic Water Condition In Deep And Thick Gravel Layer, Peng Wei, Wang Hai, Wang Zhongquan, Bu Guiling

Coal Geology & Exploration

In order to reduce the water drainage of the studied open-pit mine, a curtain wall is proposed to cut off the river supply on the north side. With full consideration of the realities of construction site, the occluded pile curtain method is applied in an areas with a high voltage line overhead. The gravel layer thickness of the construction area is 45 m and the permeability coefficient is up to 100 m/d, with 0.033 hydraulic gradient and 5℃ groundwater temperature maintained for a long time. In order to ensure fast pile formation in deep gravel layer and low temperature dynamic …


Genesis Analysis And Study On Tectonic Control On Water Of Huainan North China-Type Coal Field, Ding Tongfu, Wang Minhua, Zhao Junfeng Aug 2020

Genesis Analysis And Study On Tectonic Control On Water Of Huainan North China-Type Coal Field, Ding Tongfu, Wang Minhua, Zhao Junfeng

Coal Geology & Exploration

In order to analyze deeply the genesis and tectonic control on water of the macrostructures of the fourth stage of the Huainan North China-type coalfield, the forms of folds and faults of the Huainan coalfield were used to verify and compare the North China craton geohistory, stratigraphy, and regional tectonics. Quantitative evaluation of the impact of mining area 8 on production mines was conducted. The results show that the Huainan coalfield was formed by the superposition of the Indosinian, Yanshan and Himalayan movements. The Indosinian movement formed the Huainan coalfield at near-east-west tectonic line(body) in the first stage, and the …


Geochemical Characteristics Of Elements In The Paleogene Yunlong Formation And The Restoration Of Paleoenvironment In Lanping Basin, Liu Xiaokang, Zhang Zhibo, Zhu Zhijun, Wu Chuanfu, Wei Xingxing, Liu Haiyan, Jin Tengrui, Baima Quzong Aug 2020

Geochemical Characteristics Of Elements In The Paleogene Yunlong Formation And The Restoration Of Paleoenvironment In Lanping Basin, Liu Xiaokang, Zhang Zhibo, Zhu Zhijun, Wu Chuanfu, Wei Xingxing, Liu Haiyan, Jin Tengrui, Baima Quzong

Coal Geology & Exploration

In order to restore the sedimentary environment of the Paleogene Yunlong Formation in the Lanping basin, inductively coupled plasma mass spectrometry(ICP-MS) was used to analyze trace elements in 13 samples of gypsum, limestone, gypsum mud, mudstone and sandstone from the Paleogene Yunlong Formation in Lanping Basin. The sedimentary environments and paleoclimate are estimated based on the spider diagram of trace elements in each lithology and the characteristics of the ratio of Cu/Zn, Sr/Cu and Sr/Ba and the content of Sr. The results show that:gypsum, limestone, gypsum mud, mudstone and sandstone are all rich in Rb, Pb, Zr; gypsum and gypsum …


Applicability Of Mercury Injection Test To The Characterization Of Low Rank Coal And Its Correction Method, Liu Yinan, Liu Yong, Xin Fudong, Wei Hongyu Aug 2020

Applicability Of Mercury Injection Test To The Characterization Of Low Rank Coal And Its Correction Method, Liu Yinan, Liu Yong, Xin Fudong, Wei Hongyu

Coal Geology & Exploration

As an effective method for coal reservoir characterization, mercury intrusion has been widely used in reservoir property analysis of medium-high rank coal. However, for low-rank coal, due to its loose and brittle nature, the process of mercury intrusion will destroy the pore structure, resulting in poor applicability of mercury intrusion experiments. In order to accurately assess the damage to the pore structure of low-rank coal by mercury intrusion experiments, lignite and long flame coal were selected as the research objects, and the pore size distribution of coal was tested by mercury intrusion and nuclear magnetic resonance. The results show that …


Application Of Controllable Electric Pulse Wave Permeability-Enhancing Technology In The Low-Permeability Coal Seams, An Shigang, Chen Dianfu, Zhang Yongmin, Kong Delei, Li Yang, Zhang Di, Wang Yang Aug 2020

Application Of Controllable Electric Pulse Wave Permeability-Enhancing Technology In The Low-Permeability Coal Seams, An Shigang, Chen Dianfu, Zhang Yongmin, Kong Delei, Li Yang, Zhang Di, Wang Yang

Coal Geology & Exploration

Controllable electric pulse wave permeability-enhancing technology is one of the ideal measures for anti-reflection transformation of low-permeability coal seams. The optimization of construction schemes needs to be solved urgently. Aiming at this problem, in the low-permeability coal seam of Baode coal mine, controllable electric pulse wave permeability-enhancing technology was adopted to optimize the permeability-enhancing construction scheme of the boreholes. Test results show that the controllable electric pulse wave permeability-enhancing effect is the best under the condition of the average permeability-enhancing section of 131 m, the impact density of 0.5 times/m and the average daily extraction volume in an anti-reflection borehole …


Reasons Of Low Yield And Stimulation Measures For Cbm Wells In Junlian Area, Li Ying, Zheng Rui, Luo Kai, Zhu Yanming, Zhang Yimin Aug 2020

Reasons Of Low Yield And Stimulation Measures For Cbm Wells In Junlian Area, Li Ying, Zheng Rui, Luo Kai, Zhu Yanming, Zhang Yimin

Coal Geology & Exploration

Coalbed methane fields in Junlian area have good development potential, but the existence of a large number of low-production and low-efficiency wells has restricted the increase of productivity. This paper analyzes the coupling relationship between high-productivity wells and geological factors from the perspective of geological engineering integration, analyzes the causes of inefficient wells from three aspects of geology, drainage and engineering, and evaluates the corresponding reform measures. The results show that the formation of inefficient wells in the north and the west of the study area is mainly affected by gas-bearing properties, fault distribution, production horizons, production and drainage rhythms, …


Geochemical Characteristics And Their Origin Of Cbm In Xingxian Area, Ordos Basin, Wang Xiangye, Sun Baoping Aug 2020

Geochemical Characteristics And Their Origin Of Cbm In Xingxian Area, Ordos Basin, Wang Xiangye, Sun Baoping

Coal Geology & Exploration

The distribution of carbon and hydrogen isotope of methane is of signification in revealing the origin, the distribution of CBM reservoir, and the source evaluation of CBM. To study the origins of coalbed methane and carbon dioxide, the data of the components、carbon and hydrogen isotopes of CBM from the desorption gas of coal core from Xingxian area were analyzed. With the CBM origins chart board, and the geological environment, the geological effect of the formation and the evolution of CBM were analyzed. the ratios of CBM with different origins were estimated. The results show that the δ13C, values …


Corrosion And Degradation Of Feldspar Sandstone In Acidic Environment, Zhou Bin, Zhang Dongming, Xu Jiang, Cheng Liang, Li Jiaxin Aug 2020

Corrosion And Degradation Of Feldspar Sandstone In Acidic Environment, Zhou Bin, Zhang Dongming, Xu Jiang, Cheng Liang, Li Jiaxin

Coal Geology & Exploration

In order to study the effect of acidic environment on the corrosion and deterioration of rocks, CT images processing technology was used to analyze the meso-composition and structural changes of feldspar sandstone after soaking in acidic water. Shimadzu AGI-250 servo material testing machine was used to carry out uniaxial compression test to observe the deterioration of mechanical parameters. The results show that the total density of the feldspar sandstone decreased Ofter the acidic environment treatment, the distribution trend is homogeneous, and the mineral with higher density is formed in the local area. The secondary pores of the feldspar sandstone increased …


Sensitivity Analysis Of Disaster-Pregnant Environmental Factors For Slope Geological Hazards In Kaiyang County, Guizhou Province, Qin Yigen, Yang Genlan, Xie Jin, Liu Bangyu Aug 2020

Sensitivity Analysis Of Disaster-Pregnant Environmental Factors For Slope Geological Hazards In Kaiyang County, Guizhou Province, Qin Yigen, Yang Genlan, Xie Jin, Liu Bangyu

Coal Geology & Exploration

The geological conditions are complex in Kaiyang County, and geological disasters occur frequently. On the basis of field geological hazard investigation, 8 factors including elevation, slope, slope direction, engineering petrofabric, slope structure, fault, drainage and NDVI value are selected as the disaster-pregnant factors of slope geohazards. Based on the GIS platform, and by using the certainty factor model(CF) and the sensitivity-exponential(E), susceptibility of these 8 factors are researched. The results show that the areas with elevation from 515 to 993 m, the slope degree from 20° to 50°, the aspect of the west, the northwest and the southeast, …


Study On The Effect Of Dual-Freedom Coupling Between The Tilt Geophones And The Surface, Sun Chao, Sun Liang, He Dengke, Tian Siqing Aug 2020

Study On The Effect Of Dual-Freedom Coupling Between The Tilt Geophones And The Surface, Sun Chao, Sun Liang, He Dengke, Tian Siqing

Coal Geology & Exploration

In the process of coalfield seismic data acquisition, there is a situation of repeated geophone layout at the same point. The tilt angle difference of the geophones will leads the change of coupling condition between the geophone and the surface, which affects the quality of seismic data acquisition. In this paper, the tilt angle parameters of geophone were introduced into the coupling system of the geophone and the surface. From the point of view of vibration mechanics, the "vibration system with coupling of the dual degree of freedom" of tilt geophone was deduced. The influences of the tilt angle of …


The High-Resolution Transient Electromagnetic Detection Technology For Ultra-Shallow Layer In Coal Mine, Zhang Jun Aug 2020

The High-Resolution Transient Electromagnetic Detection Technology For Ultra-Shallow Layer In Coal Mine, Zhang Jun

Coal Geology & Exploration

In order to reduce the blind zone of the transient electromagnetic detection in mines and improve the detection accuracy, the high-resolution transient electromagnetic detection technology for the ultra shallow layer in mines is studied. The high-resolution transient electromagnetic detection technology for ultra-shallow layer in mines is not only suitable for conventional mine geological exploration, but also for high-resolution detection of shallow geological bodies such as cracks in the roof of the mine roadway, ensuring the safe and efficient mining. Through theoretical research, the feasibility of the shallow high-resolution transient electromagnetic method in mine was established; the hardware system of the …


Experimental Study On The Frequency Dispersion Response Of Composite Electrical Properties Of Coal, Meng Hui, Li Jian, Lei Dongji, Wang Yajuan Aug 2020

Experimental Study On The Frequency Dispersion Response Of Composite Electrical Properties Of Coal, Meng Hui, Li Jian, Lei Dongji, Wang Yajuan

Coal Geology & Exploration

In order to study the characteristics of frequency dispersion response of the composite electrical properties of coal, the real part R and imaginary part X of the composite resistance of coal body at different direction in different measured areas were measured, the frequency dispersion characteristics were analyzed, different classical models were used to conduct data inversion and comparison. The results show that the composite electrical property parameters(absolute value of R and X) of coal are inversely proportional to the measured area, the characteristic frequency points are not offset, the X-frequency divergence decreases with the increase of measurement area; …


Research Status And Prospect Of Drill Pipe Thread Used In Coal Mine, Tian Dongzhuang, Chen Yanyu, Li Qing, Dong Mengmeng, Mou Peiying Aug 2020

Research Status And Prospect Of Drill Pipe Thread Used In Coal Mine, Tian Dongzhuang, Chen Yanyu, Li Qing, Dong Mengmeng, Mou Peiying

Coal Geology & Exploration

Drill pipe is one of the main device for drilling construction of gas drainage, water detection and drainage and geological exploration. Due to complicated force conditions and using environment of drill pipe, accidents in boreholes caused by the failure of drill pipe threads are common. According to different structural classification, the characteristics of drill pipe thread structure in coal mines are introduced in detail; the current research status of thread stress distribution and failure analysis of thread are summarized. The research methods of thread stress distribution mainly include analytical method, finite element method and test method. The main causes of …


Design Of Piezoelectric Effect-Based Energy Recovery Device Wile Drilling, Wu Tianyu, Zheng Jun, Zhang Bo, Chen Yu, Tian Hong, Dou Bin Aug 2020

Design Of Piezoelectric Effect-Based Energy Recovery Device Wile Drilling, Wu Tianyu, Zheng Jun, Zhang Bo, Chen Yu, Tian Hong, Dou Bin

Coal Geology & Exploration

Aiming at the problem of continuous power supply of downhole instruments and the recovery of longitudinal vibration energy of drill pipe in drilling field, a new type of energy recovery device based on positive piezoelectric effect was designed. The radial dimension parameters and piezoelectric materials were designed by field experiences and geological survey reports. The piezoelectric coupling model was established based on the numerical simulation software COMSOL Multiphysics, and the length range and the best installation position of the piezoelectric plate were obtained through forced vibration analysis. Through modal analysis and frequency response research, it is obtained that the natural …


Effect Of Calcination Time On The Physicochemical Properties And Photocatalytic Performance Of Carbon And Nitrogen Co-Doped Tio2 Nanoparticles, Emile Salomon Massima Mouele, Mihaela Dinu, Franscious Cummings, Ojo O. Fatoba, Myo Tay Zar Myint, Htet Htet Kyaw, Anca C. Parau, Alina Vladescu, M. Grazia Francesconi, Sara Pescetelli, Aldo Di Carlo, Antonio Agresti, Mohammed Al-Abri, Sergey Dobretsov, Mariana Braic, Leslie F. Petrik Aug 2020

Effect Of Calcination Time On The Physicochemical Properties And Photocatalytic Performance Of Carbon And Nitrogen Co-Doped Tio2 Nanoparticles, Emile Salomon Massima Mouele, Mihaela Dinu, Franscious Cummings, Ojo O. Fatoba, Myo Tay Zar Myint, Htet Htet Kyaw, Anca C. Parau, Alina Vladescu, M. Grazia Francesconi, Sara Pescetelli, Aldo Di Carlo, Antonio Agresti, Mohammed Al-Abri, Sergey Dobretsov, Mariana Braic, Leslie F. Petrik

Mining Engineering Faculty Research & Creative Works

The application of highly active nano catalysts in advanced oxidation processes (AOPs) improves the production of non-selective hydroxyl radicals and co-oxidants for complete remediation of polluted water. This study focused on the synthesis and characterization of a highly active visible light C–N-co-doped TiO2 nano catalyst that we prepared via the sol-gel method and pyrolyzed at 350 °C for 105 min in an inert atmosphere to prevent combustion of carbon moieties. Then we prolonged the pyrolysis holding time to 120 and 135 min and studied the effect of these changes on the crystal structure, particle size and morphology, electronic properties and …


A Mechanism Of Electric Charge Losses In Adiabatically Compressed Ferroelectrics, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Jay B. Chase Jul 2020

A Mechanism Of Electric Charge Losses In Adiabatically Compressed Ferroelectrics, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Jay B. Chase

Mining Engineering Faculty Research & Creative Works

A ferroelectric depolarized by high strain-rates induced by the passage of adiabatic shock waves releases a high-density electric charge, initiating the generation of high voltage and megawatt power levels. Additionally, this depolarization process alters physical and mechanical properties that might cause energy and electric charge losses in the ferroelectric materials. We report, herein, the results of an experimental study of electric charge losses in Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 and Pb0.99(Zr0.52Ti0.48)0.99Nb0.01O3 ferroelectrics subjected to shock compression. We found that electric charge losses mainly occur in the compressed zone of ferroelectric elements, i.e., shock compression is an essential part of the charge loss mechanism. Based …


Mining The Borderlands: Industry, Capital, And The Emergence Of Engineers In The Southwest Territories, 1855-1910. Grossman, Sarah E.M. University Of Nevada Press, 2018, James Altman Jun 2020

Mining The Borderlands: Industry, Capital, And The Emergence Of Engineers In The Southwest Territories, 1855-1910. Grossman, Sarah E.M. University Of Nevada Press, 2018, James Altman

Executive Vice President & Provost Faculty Research

In Mining the Borderlands: Industry, Capital, and the Emergence of Engineers in the Southwest Territories, 1855‐1910, distinguished scholar Sarah E.M. Grossman examines the early history of commercial mining along the US‐Mexico border. She brings to the task her extensive knowledge of the region, and a forensic detective's thirst for the truth. Her mission is to understand precisely how much, and in what specific ways, various commercial mining ventures in the desert Southwest contributed not only to the economic development of the region, but also to improvements in mining techniques, engineering methods, equipment, efficiency, working conditions, mining education, and most importantly, …


Regional Distribution And Geotectonic Control Of Late Permian Tectonically Deformed Coal In Zhina Coalfield, Zhou Peiming, Gao Wei, Deng Lan, Fu Wei Jun 2020

Regional Distribution And Geotectonic Control Of Late Permian Tectonically Deformed Coal In Zhina Coalfield, Zhou Peiming, Gao Wei, Deng Lan, Fu Wei

Coal Geology & Exploration

In order to find out the tectonically deformed coal distribution law of Zhina coalfield, by sorting out and analyzing the data of more than 200 coal-bearing structural units including Bide syncline, Santang syncline, Zhuzang syncline, Arcong syncline and Guanzhai syncline in Zhina coalfield, Guizhou Province, combined with logging curve analysis, the regional distribution characteristics of coal body structure and structural control factors of No.6, No.16 and No.27 main coal seams are comprehensively analyzed. The study shows that from the west to the east, the proportion of tectonically deformed coal in Zhina coalfield increases gradually. The coal in the western part …


Surface Efficient Gas Extraction Mode Based On Full Coverage Of Working Face, Fang Jiawei, Han Baoshan, Zhou Jiajia, Wang Zhengxi, Zhang Dingliang, Liu Jia, Xu Jianjun Jun 2020

Surface Efficient Gas Extraction Mode Based On Full Coverage Of Working Face, Fang Jiawei, Han Baoshan, Zhou Jiajia, Wang Zhengxi, Zhang Dingliang, Liu Jia, Xu Jianjun

Coal Geology & Exploration

Aiming at the problems of soft and broken coal seam, low permeability, difficulty in gas extraction and low drainage efficiency in working face, a full-coverage mode for gas extraction in working face through the horizontal well group with staged fracturing roof at both ends is proposed. Taking a mine in Suxian mining area of Huaibei coalfield as an example, based on the characteristics of in-situ stress and working face distribution, combined with the analysis of gas geological conditions and coal seam mechanical properties in the area, the cross section dipole sonic logging method was used to optimize the orientation of …


Fractal Theory-Based Seepage Model Of Hershel-Bulkley Fluid In Porous Medium, Yang Xian, Lu Wei, Jin Xin, Chen Juan, Feng Xingfa Jun 2020

Fractal Theory-Based Seepage Model Of Hershel-Bulkley Fluid In Porous Medium, Yang Xian, Lu Wei, Jin Xin, Chen Juan, Feng Xingfa

Coal Geology & Exploration

Slurry is a kind of widely-used engineering fluid. Slurry will seeps into the formation in the process of construction, which has a certain impact on the project. In order to make deeper study on the seepage mechanism of slurry, the formation is simulated as porous medium, the slurry is simulated as Hershel-Bulkley fluid which can more comprehensively reflect its rheological properties, and the seepage model of Hershel-Bulkley fluid in porous medium was established based on Fractal theory. Based on the calculation results of seepage model, the effect of pressure gradient, flow index, consistency coefficient and porosity on the instantaneous average …


Development Characteristics Of Water Conducted Fracture Zone Based On Overburden Structural Effect, Cao Zubao, Wang Qingtao Jun 2020

Development Characteristics Of Water Conducted Fracture Zone Based On Overburden Structural Effect, Cao Zubao, Wang Qingtao

Coal Geology & Exploration

In order to study the roof water disaster caused by coal mining in Huanglong coalfield, taking mining failure of layered overburden as research object, four typical composite structural models for coal-soft rock-hard rock-soft rock-hard rock(combination I), coal-soft rock-soft rock-hard rock-hard rock(combination Ⅱ), coal-hard rock-soft rock-hard rock-soft rock(combination Ⅲ) and coal-hard rock-hard rock-soft rock-soft rock(combination IV) were generalized. Numerical simulation and theoretical calculation were used to analyze the mining failure characteristics of different overburden combinations and correlation between water conducting fissures and lithologic combination structure of overburden. The law of the effect of overburden structure on the development height of water …


The Law Of Soaking Infiltration And Collapse Deformation In Typical Loess-Paleosol Series, Zhao Jingang, Lyu Yuanqiang, Chao Jun, Yang Zhe, Xia Meng Jun 2020

The Law Of Soaking Infiltration And Collapse Deformation In Typical Loess-Paleosol Series, Zhao Jingang, Lyu Yuanqiang, Chao Jun, Yang Zhe, Xia Meng

Coal Geology & Exploration

In order to investigate the law of moisture migration and collapse deformation of the typical loess-paleosol series, on the basis of water immersion test of the large test pits of Xi’an North-airport intercity rail transit in the loess tableland of Weibei, the real-time in-site observation was adopted, the soaking infiltration and collapse deformation of collapsible soil layer under conditions of non water seepage hole were traced and tested. The results show that: The movement of water immersion is dominated by vertical movement in the early stage. The whole form is like a continuous increase of “weight” shape. As the water …


Numerical Calculation Of Temperature Field Of Freeze-Sealing Pipe Roof Method In Gongbei Tunnel, Long Wei, Rong Chuanxin, Duan Yin, Guo Ke Jun 2020

Numerical Calculation Of Temperature Field Of Freeze-Sealing Pipe Roof Method In Gongbei Tunnel, Long Wei, Rong Chuanxin, Duan Yin, Guo Ke

Coal Geology & Exploration

This paper took the Gongbei tunnel in the Zhuhai Connection Section of the Hong Kong-Zhuhai-Macao Bridge as an example to study the development of the temperature field of the Freeze-Sealing Pipe Roof Method. Based on the heat transfer theory of two-dimensional porous media, the FEM software COMSOL was used to numerically analyze the actual working conditions of the active freezing period, the numerical calculation was verified by field measurement. The development and distribution of the temperature field before and after the opening of the special-shaped freezing pipes was studied. The results showed that: when freezing for 30 days, the concrete …