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Key Geological Factors And Evaluation Methods For Huge Low-Rank Coalbed Methane Reservoirs:Taking Bayanhua Depression In Erlian Basin As An Example, Yao Haipeng, Lyu Weibo, Wang Kaifeng, Li Ling, Li Wenhua, Lin Haitao, Li Fengchun, Li Zheng Feb 2020

Key Geological Factors And Evaluation Methods For Huge Low-Rank Coalbed Methane Reservoirs:Taking Bayanhua Depression In Erlian Basin As An Example, Yao Haipeng, Lyu Weibo, Wang Kaifeng, Li Ling, Li Wenhua, Lin Haitao, Li Fengchun, Li Zheng

Coal Geology & Exploration

In order to evaluate the potential of low rank CBM resources with large thickness, Bayanhua depression in Erlian basin is studied. By studying the genesis of CBM, buried depth of coal seam, thickness of coal seam, physical properties of coal reservoir, gas content, hydrogeology and cap rock, the key geological elements of thick and low coal rank coal reservoirs are summarized. Furthermore, a new low rank CBM resource potential evaluation method is established, and the favorable and target zones for CBM exploration and development in Bayanhua depression are delineated. The results show that the main coal-bearing strata in Bayanhua depression …


“Scenario-Response”-Based Emergency Decision-Making Mechanism Of Mine Water Inrush Disaster, Lian Huiqing, Yang Junwen, Han Ruigang, Meng Lu, Han Yong Feb 2020

“Scenario-Response”-Based Emergency Decision-Making Mechanism Of Mine Water Inrush Disaster, Lian Huiqing, Yang Junwen, Han Ruigang, Meng Lu, Han Yong

Coal Geology & Exploration

The urgency, complexity and uncertainty of mine flood accidents determine that traditional emergency decision-making models are difficult to meet the requirements of efficient emergency rescue. Using the “scenario-response” model for emergency decision-making of mine flood accidents can effectively solve the timely real-time decision-making of specific disaster scenario after disasters occur. Using a multi-case analysis method to analyze 11 typical mine flood accidents in recent years, based on the general structural description of the accident, six elements of the mine flood scenario were summarized(inrush water source, water inrush channel, water inrush position, water output, submerged range, living space) as the scenario …


Characteristics And Sedimental Control Of Mine Water Outflow In Hujirt Mining Area, Liang Xiangyang, Yang Jian, Cao Zhiguo Feb 2020

Characteristics And Sedimental Control Of Mine Water Outflow In Hujirt Mining Area, Liang Xiangyang, Yang Jian, Cao Zhiguo

Coal Geology & Exploration

Hujirt mining area in Ordos basin is a deep-buried Jurassic coalfield with high water pressure, large water volume and uneven water abundance. Each mine is facing serious pressure of mine water hazard prevention and control. In order to clarify the water outflow conditions and main controlling factors of the coal seam roof of the mine in this area, the research on geological deposit and water-producing horizon of roof boreholes, water-inrush from boreholes and water-inrush from working face was carried out. The results showed that within the water conducting fractured zone of Hujirt mining area, there are mainly meandering river sedimentary …


Mining Response And Dynamic Reinforcement For Narrow Coal Pillar Next To Goaf In Working Face 1402 Of Xin’An Coal Mine, Wang Beifang, Liang Bing, Liu Wei, Zhang Jing, Chi Haibo, Liu Yahui Feb 2020

Mining Response And Dynamic Reinforcement For Narrow Coal Pillar Next To Goaf In Working Face 1402 Of Xin’An Coal Mine, Wang Beifang, Liang Bing, Liu Wei, Zhang Jing, Chi Haibo, Liu Yahui

Coal Geology & Exploration

with the increase of integrating coal mines under national coal de-capacity policy, the mining instability phenomenon of narrow coal pillar next to goaf is increasingly prominent, which has seriously restricted the safety and efficient production in coal mines. Therefore, stability control engineering problem of narrow coal pillar next to goaf, near No.5 drilling field on air return roadway of repeated mining face 1402 in Xin'an coal mine was as study object, a method of combining numerical simulation and theoretical analysis was used to explore the mining disturbance response characteristics of narrow coal pillar stability next to goaf, near No.5 drilling …


Anisotropic Shear Behavior Of Rock Joint Based On 3d Printing Technology, Xu Xunhui, Zhang Guobiao, Bao Han, Yan Changgen Feb 2020

Anisotropic Shear Behavior Of Rock Joint Based On 3d Printing Technology, Xu Xunhui, Zhang Guobiao, Bao Han, Yan Changgen

Coal Geology & Exploration

Topography is an important factor affecting the shear behavior of joint. Furthermore, there are certain connections between the anisotropy of topography and the anisotropy of shear behavior. In this study, 3D laser scanning technology and 3D printing technology were used to make molds for simulating the topography of natural joint. Then, the cement mortar samples with dimension of 100 mm×100 mm×150 mm were cast, and shear tests with different shear directions under different normal stresses were conducted. The results indicate that obvious anisotropy has been shown in the joint shear behavior, which is reflected in the peak shear strength and …


Three-Dimensional Stress Evolution And Comprehensive Treatment Technology For Super-Long Working Face Across Abandoned Roadway With Large Section, Wang Yan, Xiong Zuqiang, Zhao Gaobo Feb 2020

Three-Dimensional Stress Evolution And Comprehensive Treatment Technology For Super-Long Working Face Across Abandoned Roadway With Large Section, Wang Yan, Xiong Zuqiang, Zhao Gaobo

Coal Geology & Exploration

In order to solved the problem of super-long working face across abandoned roadway with large section, which is easy to cause rib spalling and roof falling, based on a super-long working face in Chengzhuang mine of Jincheng, a three-dimensional model of abandoned with large section roadway was established. The roof of working face was divided into three parts: coal pillar roof, abandoned roadway roof and mining area roof. The criterion of pillar instability was deduced and the roof stress evolution process of large section abandoned roadway was analyzed by FLAC3D numerical simulation. The results show that when the W …


Multidimensional Deformation Monitoring Using Insar Technology In Yuxian Mining Area, Du Jiantao, Yan Li, Zhao Chaoying Feb 2020

Multidimensional Deformation Monitoring Using Insar Technology In Yuxian Mining Area, Du Jiantao, Yan Li, Zhao Chaoying

Coal Geology & Exploration

Yuxian County in Hebei Province is one of the largest mining areas in North China. This area has been suffering serious ground deformation due to underground mining activity, which not only threatens mining safety, but also seriously damages local ecological environment. To obtain the surface deformation map of the overall mining area and to analysis the spatiotemporal evolution features, 61 C-band descending track and ascending track Sentinel-1A/B images from July 2017 to September 2018 were processed based on Interferometric Synthetic Aperture Rader(InSAR) technique. In addition, the two-dimensional deformation time series of Xixizhuang mine were obtained by using the multi-dimensional deformation …


Development And Application Of Macroscopic And Mesoscopic Analytical Testing Instrument For Reinforcement-Soil Interface Characteristics, Yi Fu, Du Changbo, Wang Zhengyun, Yu Ben Feb 2020

Development And Application Of Macroscopic And Mesoscopic Analytical Testing Instrument For Reinforcement-Soil Interface Characteristics, Yi Fu, Du Changbo, Wang Zhengyun, Yu Ben

Coal Geology & Exploration

To analyze the interaction characteristics of soil-reinforcement interface more comprehensively, an experimental instrument for macro-and micro-analysis of interface characteristics of visible reinforced soils was developed and can be used for direct shear and pull-out tests with different geosynthetics and fillers. The instrument improves the size of test box, facilitates the comparative analysis of the two tests, and has an image recording system which enables the microscopic analysis of test process. The direct shear and pull-out tests of geosynthe­tics(geogrid and geotextile) reinforced tailings sand were carried out with the newly developed apparatus. The results show that the interface parameters(pseudo-cohesion and pseudo …


Application Of Far And Near Trace Attributes For Avo Analysis In Deep Water Area In Qiongdongnan Basin, Liu Shiyou, Zhang Yingzhao, Li Yangsen, Yan Anju, Zhang Haiyang Feb 2020

Application Of Far And Near Trace Attributes For Avo Analysis In Deep Water Area In Qiongdongnan Basin, Liu Shiyou, Zhang Yingzhao, Li Yangsen, Yan Anju, Zhang Haiyang

Coal Geology & Exploration

For prestack seismic data with low signal-to-noise ratio(SNR), the effect of traditional AVO rendezvous analysis and intercept gradient product attribute(P×G attribute) may not be ideal. In order to extract the information of AVO attribute effectively, this paper starts from the prestack partial superposition body, according to the relative relation of the far and near track part superposition body, the far and near attribute factor similar to the P×G attribute was constructed, in which the near track stack reflects the intercept attribute, and the near-far stack difference reflects the intercept attribute, which is similar to the …


Forward Response Analysis Of Shield Advanced Detection With Moving Array Electrode, Zhao Shuanfeng, Bai Yunrui, Huang Tao, Wei Mingle Feb 2020

Forward Response Analysis Of Shield Advanced Detection With Moving Array Electrode, Zhao Shuanfeng, Bai Yunrui, Huang Tao, Wei Mingle

Coal Geology & Exploration

Aiming at problems of serious electromagnetic interference, difficult application in TBM(Tunnel Boring Machine) tunnel construction and so on, a method of shield advanced detection based on moving array electrodes is adopted. Using Comsol Multiphysics finite element simulation software to establish geoelectric model, forward response analysis is carried out for various geological conditions. The results show that adding the protective electrodes can obviously enlarge the voltage distribution range, which means the detection range increases. In order to improve the detection effect, it is necessary to add protective electrodes. Changes in the size, shape and position of the anomalous body will exhibit …


Frequency Dispersion Mechanism Of Complex Resistivity Of Coal, Guo Yuehui, Zhang Yugui, Li Jian, Zhou Meng Feb 2020

Frequency Dispersion Mechanism Of Complex Resistivity Of Coal, Guo Yuehui, Zhang Yugui, Li Jian, Zhou Meng

Coal Geology & Exploration

In order to study the physical mechanism of frequency dispersion of complex resistivity of coal at 0-200 kHz, the amplitude-frequency and phase-frequency of complex resistivity of coal are measured under variable frequency of constant current. Using the Fourier inverse transform to convert the frequency domain data of complex resistivity of coal into time domain data; Using the Cole-Cole model, the complex resistivity dispersion data are fitted; Drawing on the electric double layer deformation hypothesis theory, the dispersion mechanism of complex resistivity of coal is studied by comparing the frequency dispersion of sandstone. The results show that in the current frequency …


The Key Technology For Drilling Horizontal Well In Coal Seam Roof In Qianbei Mining Area, Hu Xinpeng, Zhao Yongzhe, Xu Kanshe, Wang Linjie, Li Peng, Duan Huijun Feb 2020

The Key Technology For Drilling Horizontal Well In Coal Seam Roof In Qianbei Mining Area, Hu Xinpeng, Zhao Yongzhe, Xu Kanshe, Wang Linjie, Li Peng, Duan Huijun

Coal Geology & Exploration

primary ways to develop the soft coal seam CBM. Aiming at the complex geological conditions and reservoir conditions in Qianbei mining area of Guizhou Province, in order to solve the problems of horizontal well leakage, well trajectory control and solid completion in the horizontal well drilling of coal seam roof, the key technology of horizontal well drilling of coal seam roof in Qianbei mining area, with the accurate control of trajectory as the core, and the technology of preventing leakage, eccentricity and solid completion are combined. Combined with on-site drilling practice, the problems of difficulties in horizontal well drilling were …


Microscopic Fabric Characteristics Of Typical Red Soft Rock In Badong Formation Under Uniaxial Compression Test, Xiao Zunqun, Wang Xin, Tang Dongsang, Dong Qiongying, Jiang Yinan, Yang Kai, Cao Tongtong, Deng Zhen Dec 2019

Microscopic Fabric Characteristics Of Typical Red Soft Rock In Badong Formation Under Uniaxial Compression Test, Xiao Zunqun, Wang Xin, Tang Dongsang, Dong Qiongying, Jiang Yinan, Yang Kai, Cao Tongtong, Deng Zhen

Coal Geology & Exploration

Red silty mudstone and argillaceous siltstone are the representatives of special rock and soil in Badong Formation, are easy to disintegrate when encountering water. According to the uniaxial compression test of rock samples, a numerical model of medium and soft rock uniaxial compression test was established based on PFC2D program. With the characteristics of stress-strain curve, subsection quantitative parameter calibration method was used to calibrate the microscopic parameters of soft rock samples. The adjustment method and the ratio of tangential bond strength(σcc) control specimen under uniaxial compression failure mode. The uniaxial compression test of silty …


Analysis Of Suitable Development Technology Of Cbm(Gas) In Guizhou, Xu Xiaoqian, Meng Yingfang, Duan Zhengpeng, Li Guohong, Li Qingsong Dec 2019

Analysis Of Suitable Development Technology Of Cbm(Gas) In Guizhou, Xu Xiaoqian, Meng Yingfang, Duan Zhengpeng, Li Guohong, Li Qingsong

Coal Geology & Exploration

In recent years, technical bottlenecks have been encountered in the practice of CBM exploration and development in Guizhou Province, selecting suitable development technology is one of the key issues. Based on the background that CBM exists in thin coal seams and geological structures are complicated in Guizhou, combined with successful development and utilization of CBM, the CBM development and utilization technology suitable for complex geological conditions in Guizhou was put forward. Air drilling is recommended for drilling in Guizhou, according to different distance of thin seams, such as optical casing composite fracturing and salvageable bridge plug fracturing can be used. …


Key Technology Of Drilling In-Seam Directional Borehole Of 3 000 M In Underground Coal Mine, Shi Zhijun, Dong Shuning, Yang Junzhe, Xu Chao, Hao Shijun, Li Quanxin, Chen Dianfu, Yao Ke, Liu Jianlin, Tian Dongzhuang Dec 2019

Key Technology Of Drilling In-Seam Directional Borehole Of 3 000 M In Underground Coal Mine, Shi Zhijun, Dong Shuning, Yang Junzhe, Xu Chao, Hao Shijun, Li Quanxin, Chen Dianfu, Yao Ke, Liu Jianlin, Tian Dongzhuang

Coal Geology & Exploration

The pre-mining gas governance mode in Baode coal mine requires that long directional borehole of more than 3 000 m can be drilled along coal seam. In view of the existing technology and equipment, there are technical problems in the construction of ultra-long directional borehole, such as the difficulty of sliding drilling, the large hydraulic pressure consumption in inlet waterway, the limited transmission distance of wireline MWD signal, and incapability of flushing liquid recycle. The technology of friction reduction in sliding drilling based on the hydraulic thrust of DHM and the torsion penetration of the ultra-long drilling tool, the technology …


Extension Model Of Fracturing Cracks Of Translayer Horizontal Well In Roof Of Soft Coal Reservoir, Wang Zhirong, Hu Kai, Yang Jie, Chen Lingxia Dec 2019

Extension Model Of Fracturing Cracks Of Translayer Horizontal Well In Roof Of Soft Coal Reservoir, Wang Zhirong, Hu Kai, Yang Jie, Chen Lingxia

Coal Geology & Exploration

In order to study the propagation rules of hydraulic fracturing crack formed by a horizontal well in roof to coal seam, taking the Permian-Carboniferous coal field in North China as an example, through the classical theory of fracture mechanics, damage mechanics and fluid mechanics, combined with field actual data, the modeling and verification of the space-time evolution law of the crack propagation distance and fracturing time were carried out. Firstly, considering the additional stress of perforation, the characteristics of primary fracture and the permeability characteristics of rock formation, the calculation formula of cracking pressure of vertical hydraulic fracture caused by …


Technology Feasibility Of Gas Drainage With Comb-Shaped Long Borehole In Floor Instead Of Translayer Borehole, Li Hong, Liu Mingju, Hao Guangsheng, Deng Qigen, Dong Yanjun Dec 2019

Technology Feasibility Of Gas Drainage With Comb-Shaped Long Borehole In Floor Instead Of Translayer Borehole, Li Hong, Liu Mingju, Hao Guangsheng, Deng Qigen, Dong Yanjun

Coal Geology & Exploration

Drainage technology of translayer borehole in floor roadway and directional long hole are the most important gas control measures in high gas and outburst-prone mining face at present. The coal seam in Zhaozhuang mine has the characteristics of being soft and low gas permeability. It is difficult to drill and form holes in a coal seam. For gas control, the major method is to drill a translayer borehole to eliminate gas outburst, supplemented by in-seam gas drainage boreholes. However, there are shortcomings such as large engineering volume, long construction period and high cost of drilling in floor rock roadway. The …


An Improved Method For Characterizing Coal Metamorphism By Xrd, Wang Chao, Zhao Younan, Wang Zhenwei, Lu Zhaolin Dec 2019

An Improved Method For Characterizing Coal Metamorphism By Xrd, Wang Chao, Zhao Younan, Wang Zhenwei, Lu Zhaolin

Coal Geology & Exploration

At present, the X-ray measurement method of coal metamorphism has the problem that the γ band is not well divided, the δ peak information is not used, and the background of the bottom is unreasonable. The X-ray diffraction pattern of coal with different metamorphosed degrees is compared and studied. It is proposed to correct the metamorphic coefficient formula by using the information of the slope of the 002 peak, the extended half-height width and the δ peak without deducting the so-called background information. The calculation of the XRD patterns of coal samples with different degrees of metamorphism is verified. The …


Effect Of False Boundary Of Microscopic Image On Automatic Identification Of Maceral Group, Song Xiaozhong Dec 2019

Effect Of False Boundary Of Microscopic Image On Automatic Identification Of Maceral Group, Song Xiaozhong

Coal Geology & Exploration

In automatic detection of coal petrology by image analysis technology, it is found that the boundary of various components in the microscopic image of coal petrology demonstrates a "rim" of gray transition zone, and the pixel of this rim cannot reflect the true gray level of the components on both sides. In order to analyze its influence on the identification and detection of macerals, the characteristics and causes of the false boundary between various adjacent components were studied with analysis of microscopic images collected from a large number of coal samples in China. Generally, the false boundary is ring-shaped or …


Effects Of Iron-Nickel Ion Combination On Methane Produced By Lignite Fermentation, Xia Daping, Huang Song, Zhang Huaiwen Dec 2019

Effects Of Iron-Nickel Ion Combination On Methane Produced By Lignite Fermentation, Xia Daping, Huang Song, Zhang Huaiwen

Coal Geology & Exploration

In order to study the mechanism of the influence of exogenous optimal iron-nickel ions combination on the gas production process of fermentation, taking Daliuta lignite as an example, experiments were carried out with different contents of iron-nickel ions and the optimal concentration of single ions was elected. The optimal combination concentration of iron-nickel ions were determined by combined design of quadratic regression and common rotation. The fermentation broth of experiment group and blank group(not to added any ions), the coal sample of before and after experiment were analyzed by gas chromatography, X-ray diffraction, Fourier transform infrared spectroscopy, etc. The results …


Origin And Geochemical Characteristics Of Coalbed Methane In Abandoned Coal Mines, Panzhuang Block, Southern Qinshui Basin, Liu Chao, Feng Guorui, Zeng Fangui Dec 2019

Origin And Geochemical Characteristics Of Coalbed Methane In Abandoned Coal Mines, Panzhuang Block, Southern Qinshui Basin, Liu Chao, Feng Guorui, Zeng Fangui

Coal Geology & Exploration

In order to analyze the carbon and oxygen composition and origin of the coal seam gas(CSG) in abandoned mines, Panzhuang block, south of Qinshui basin, in this paper, the coalbed methane and produced water samples were collected. The results show that the CSG of abandoned mines is dominated by CH4, the average is 91.99%, with minor amounts of N2(6.73%) and CO2(1.26%). The δ13C values of CH4 range from -31.36‰ to -33.53‰, with an average of -32.25‰, the hydrogen isotope(δD) value is between -182.76‰ and -193.20‰, and the average value …


Mine Water Inrush Rescue Model Based On Optimized Spfa Algorithm, Cai Mingjie, Zhu Xi’An, Liu Demin, Wang Zhangang Dec 2019

Mine Water Inrush Rescue Model Based On Optimized Spfa Algorithm, Cai Mingjie, Zhu Xi’An, Liu Demin, Wang Zhangang

Coal Geology & Exploration

Due to the occurrence of coal mine water inrush accidents, it is easy to cause major personnel and property losses. In order to improve the emergency rescue capability of mine water inrush disasters and reduce the water inrush hazard, a mine water inrush rescue route model was proposed. The undirected map and the adjacency list were used to describe and store the mine roadway network. According to the calculation ratio of the height of the water level and the height of underground personnel in roadway, the safety coefficient of the roadway was calculated, and then the equivalent length of the …


Optimization Study On Correlation Method Of Multiple Coal Seams, Shu Jiansheng, Ma Liang, Jia Lilong Dec 2019

Optimization Study On Correlation Method Of Multiple Coal Seams, Shu Jiansheng, Ma Liang, Jia Lilong

Coal Geology & Exploration

At present, the development trend of coal mining in China is transferring from the east to the western regions. The Yan'an Formation coal bearing measures middle Jurassic is the most widely distributed in the west, it is of the continental sedimentary environment, which has the characteristics of big change of lithofacies, multiple coal seams, unstable coal seams and less marker, there are difficulties in coal seam correlation, such as lack of basis and multi-solution phenomenon. Based on the wide application of high precision seismic exploration and digital logging technology, the fine correlation of terrestrial multi-coal seams was carried out by …


Simulation Of Seepage Water Inrush Mechanism And Strength Controlling Factors Of Collapse Column, Huo Bingjie, Xie Zhenhua, Fan Zhanglei, Jing Xuedong Dec 2019

Simulation Of Seepage Water Inrush Mechanism And Strength Controlling Factors Of Collapse Column, Huo Bingjie, Xie Zhenhua, Fan Zhanglei, Jing Xuedong

Coal Geology & Exploration

In order to study the mechanism and main control factors of seepage water inrush in roadway affected by collapse columns, Darcy, Brinkman and N-S equations were used to describe the linkage system of flow field in aquifer, collapse column and water inrush roadway. Variables such as different parameters and different boundaries were selected to analyze the main factors influencing the seepage water inrush intensity of collapse columns. The results show that under the conditions of constant pressure and flow, the increase of aquifer permeability will lead to the increase of flow velocity in an area where the aquifer meets the …


Particle Swarm Optimization-Based Bionic Principle For Solving Hydrodynamic Dispersion Coefficient In Jiang'an Campus, Mei Jie, Li Guangwei, Xia Chengcheng, Liu Yaping, Liu Wen, He Xinyue Dec 2019

Particle Swarm Optimization-Based Bionic Principle For Solving Hydrodynamic Dispersion Coefficient In Jiang'an Campus, Mei Jie, Li Guangwei, Xia Chengcheng, Liu Yaping, Liu Wen, He Xinyue

Coal Geology & Exploration

Hydrodynamic dispersion coefficient is an important parameter in the study of solute transport in groundwater. In order to understand the transport law of pollutants in groundwater, the particle swarm optimization(PSO) algorithm based on bionic principle is used to solve the hydrodynamic dispersion coefficient of phreatic aquifer under natural flow field in the dispersion test site of Jiang'an Campus of Sichuan University. Compared with the least-square method and the standard curve comparison method, the results show that the results of the standard curve method are subject to subjective influence, and the errors are relatively large. The results of least square method …


Surface Subsidence Law Caused By Fully Mechanized Caving Mining Under Railway, Deng Niandong, Yao Ting, Shang Hui, Liu Donghai Dec 2019

Surface Subsidence Law Caused By Fully Mechanized Caving Mining Under Railway, Deng Niandong, Yao Ting, Shang Hui, Liu Donghai

Coal Geology & Exploration

In order to ensure the safe running of the special railway for Guozhuang coal mine, the law of surface movement and deformation in goaf of the coal mine was studied on the basis of the analysis of the actual observation data, the monitoring scheme and control measures of railway under dynamic coal mining conditions were put forward in accordance with that. The results show that the surface movement and deformation are intense, the subsidence value is large, but the subsidence velocity is relatively small on account of fully mechanized caving; Surface subsidence coefficient, the main impact tangent tanβ, …


Nishihara Acceleration Model-Based Experiment Of Creep Characteristics Of Coal, Qu Lina, Li Bo Dec 2019

Nishihara Acceleration Model-Based Experiment Of Creep Characteristics Of Coal, Qu Lina, Li Bo

Coal Geology & Exploration

For conquering limitation that the traditional Nishihara model cannot describe the accelerated creep characteristics of coal body, according to the visco-elastic-plastic flow characteristics of coal in the accelerated creep stage, a nonlinear visco-elastic-plastic model was used to replace the ideal viscoelastic-plastic body in Nishihara model to establish the improved Nishihara acceleration model. And creep equation of the improved model under equal confining pressure triaxial condition was also deduced. Afterwards, the improved accelerated creep model was analyzed by the creep test data of coal specimens in the triaxial creep tests using the method of model identification. The results show that the …


Shear Strength Characteristics Of Slope Soil In Dumping Site In High-Cold Mining Area, Zhou Linhu, Yang Youqing, Hu Xiasong, Li Xilai, Wang Tao, Liu Changyi Dec 2019

Shear Strength Characteristics Of Slope Soil In Dumping Site In High-Cold Mining Area, Zhou Linhu, Yang Youqing, Hu Xiasong, Li Xilai, Wang Tao, Liu Changyi

Coal Geology & Exploration

The paper aims to study the shear strength characteristics and the influencing factors of the root-soil composite systems of herbs in the dump slope of the high-cold mining area. The dumping site of Jiangcang mining area of Muli Coalfield, located in the northeastern Qinghai-Tibet Plateau, was selected as the study area. For the dump slope which was planted with Elymusnutans Griseb., combined with Poacrymophilakeng, density, moisture content and root content of different depths of root-soil composite systems below the surface of slope were tested; the cohesion and the internal friction angle of soil without roots and root-soil composite systems …


Optimization Of Surface Contact-Based Thermal Conductivity Model Of Cemented Particles, Chen Yuanjiang, Jiang Zhiqiang, Tan Zhiren Dec 2019

Optimization Of Surface Contact-Based Thermal Conductivity Model Of Cemented Particles, Chen Yuanjiang, Jiang Zhiqiang, Tan Zhiren

Coal Geology & Exploration

In order to explore better the variation law of thermal conductivity of geomaterials, and reduce the thermal damage caused by the problem, according to the structural characteristics of the cemented particles, combined with the effective medium thermal conductivity model and the surface contact thermal conductivity model, the effective thermal conductivity calculation model suitable for the geotechnical cemented particulate material was constructed, and the state of the particulate matter and the cementitious matrix were considered. The transient hot wire method was applied to test the thermal conductivity of the experimental test block, and the predicted values were compared with the measured …


Numerical Calculation Of Heat Transfer In Single Medium-Deep Geothermal Well, Shang Hongbo, Zhao Chunhu, Jin Dewu, Xu Shuanhai, Wang Xiaodong, Zhang Weidong, Han Yongliang Dec 2019

Numerical Calculation Of Heat Transfer In Single Medium-Deep Geothermal Well, Shang Hongbo, Zhao Chunhu, Jin Dewu, Xu Shuanhai, Wang Xiaodong, Zhang Weidong, Han Yongliang

Coal Geology & Exploration

Medium-deep geothermal single well heat transfer is a technology of developing geothermal energy to "obtain heat without extracting groundwater". This technology has the advantages of not damaging the groundwater environment and taking more heat. However, there are few studies on the numerical calculation of single well heat transfer above 3000m depth. In this paper, based on the geothermal geological conditions in Xi'an, the numerical method was used to calculate the heat transfer of a medium-deep geothermal single well with different well structures (L-shaped directional wells and cluster directional wells) under the scenario of continuous operation of a heating season. The …