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Full-Text Articles in Mining Engineering

Characteristics And Genetic Mechanism Of Low Sulfate In High-Salt Groundwater Of Permian Sandstone In Fudong Mining Area, Huainan, Jiang Chunlu, Huang Wendi, Fu Xianjie, Zheng Liugen, Cheng Shigui, Shan Chonglei Nov 2023

Characteristics And Genetic Mechanism Of Low Sulfate In High-Salt Groundwater Of Permian Sandstone In Fudong Mining Area, Huainan, Jiang Chunlu, Huang Wendi, Fu Xianjie, Zheng Liugen, Cheng Shigui, Shan Chonglei

Coal Geology & Exploration

Hydrogeochemistry research of groundwater in coal mining areas is of great significance to the prevention and control of mine water and the comprehensive utilization of water resources. In terms of the low surfate of Permian sandstone water in Fudong mining area, Anhui Huainan Coalfield, the hydrochemical characteristics, water-rock interaction and low sulfate genesis of sandstone water were studied through water sampling and test by multivariate statistical method, in combination with the hydrogeological condition analysis and the sulfur and oxygen isotope technology. The results show that the Permian sandstone water in the study area is weakly alkaline, with an average TDS …


Evaluation Of Water Quality And Identification Of Pollution Factors In Mining Subsidence Area With High Phreatic Water Level, Hu Lin, Chen Yongchun, Xu Yanfei, Li Bing, Wang Jin, An Shikai, Chen Chen, Sun Hongjie, Miao Wei Nov 2023

Evaluation Of Water Quality And Identification Of Pollution Factors In Mining Subsidence Area With High Phreatic Water Level, Hu Lin, Chen Yongchun, Xu Yanfei, Li Bing, Wang Jin, An Shikai, Chen Chen, Sun Hongjie, Miao Wei

Coal Geology & Exploration

Huainan mining area is characterized by a high phreatic water level, as well as a wide range and large area of coal mining subsidence areas, with the water quality monitoring data missing and prominent water environment. Therefore, the evaluation of water quality monitoring and identification of pollution factors in large subsidence area is of great significance to regional water environmental governance. Specifically, the water quality of the subsidence area was evaluated with the Nemerow pollution index method by testing the water samples collected from 175 sampling points in the study area. Meanwhile, the eutrophication state of water bodies was evaluated …


A Method For Evaluating Aquiclude Stability In The Water Conservation-Based Mining Of Shallowly Buried Coal Seams In Ecologically Vulnerable Areas In Northwest China, Li Heng, He Tao, Guo Bin Nov 2023

A Method For Evaluating Aquiclude Stability In The Water Conservation-Based Mining Of Shallowly Buried Coal Seams In Ecologically Vulnerable Areas In Northwest China, Li Heng, He Tao, Guo Bin

Coal Geology & Exploration

Water conservation and coal mining are both critical to Northwest China. Water conservation-based coal mining is an important technology for the coordinated development of coal and water resources in this region. In this technology, the evaluation of aquiclude stability is critical. Due to the shallow depth of coal seams, intense topographic cutting, and complex changes in near-surface aquifers in the ecologically vulnerable areas in Northwest China, there exist large errors between traditional methods for aquiclude evaluation and the actual hydrological observations in these areas. To address this challenge, this study develops using the 3D geological modelling combined with numerical simulation …


Micp Restoration Law Of Coal Mining Induced Ground Fissures And Its Influencing Factors, Li Tao, Gao Ying, Yan Jingwang, Zhang Jiarui, Kou Guigui, Ma Tengfei, Mei Aoran Nov 2023

Micp Restoration Law Of Coal Mining Induced Ground Fissures And Its Influencing Factors, Li Tao, Gao Ying, Yan Jingwang, Zhang Jiarui, Kou Guigui, Ma Tengfei, Mei Aoran

Coal Geology & Exploration

The coal mining induced ground fissures in the loess covered area of northwest China cause shallow groundwater resource leakage and soil instability. Therefore, the experimental study was conducted on Microbial Induced Carbonate Precipitation (MICP) restoration of coal mining induced ground fissures in the loess covered area. Specifically, the characteristics of mining induced ground fissures were observed and their development characteristics were revealed based on Ningtiaota Coal Mine in northern Shaanxi. The coal mining induced ground fissures in loess were classified with consideration to the observed mine pressure. Based on the classification and characteristics of coal mining induced ground fractures, the …


Detection Of Small Objects In Open-Pit Coal Mine Stopes Using Uav Remote Sensing Images, Liu Mingrui, Che Ben, Dong Hongbo, Zhu Ruoli Nov 2023

Detection Of Small Objects In Open-Pit Coal Mine Stopes Using Uav Remote Sensing Images, Liu Mingrui, Che Ben, Dong Hongbo, Zhu Ruoli

Coal Geology & Exploration

Open-pit coal mine stopes witness frequent vehicle accidents due to their complex terrains. Therefore, accurately positioning vehicles in the stopes is critical to safe coal mining. To overcome the inaccurate positioning of small targets in the mining areas using Unmanned aerial vehicle (UAV) remote sensing images, this study proposed an improved YOLOv7 model for object detection. First, to expedite the reasoning of the YOLOv7 network, the ELAN module in the original YOLOv7 model was improved by introducing partial convolution. Based on this, the eSE channel attention mechanism was combined to form the PConv-eSE convolution attention module. The purpose is to …


Mechanical Properties And Strength Deterioration Mechanism Of Soil In Inner Dump Of Open-Pit Coal Mine Under The Action Of Freeze-Thaw Cycles, Zhang Heyong, Wang Xuedong, Zhu Yongdong, Wang Haipeng, Qi Lihui Nov 2023

Mechanical Properties And Strength Deterioration Mechanism Of Soil In Inner Dump Of Open-Pit Coal Mine Under The Action Of Freeze-Thaw Cycles, Zhang Heyong, Wang Xuedong, Zhu Yongdong, Wang Haipeng, Qi Lihui

Coal Geology & Exploration

In order to investigate the influence mechanism of freeze-thaw cycles on the structure and mechanical properties of soil, the typical clay soil in the inner dump of Yuanbaoshan open-pit coal mine in Inner Mongolia was taken as the research object, and the simulation analysis of the internal temperature, moisture and stress fields of the soil was carried out through laboratory freeze-thaw cycle tests and MatDEM numerical simulation. The results show that: freeze-shrinkage occurs to the soil in the dump after the freeze-thaw cycles, and the stress-strain curve shows the trend of strain softening at low confining pressure for shear failure, …


Intelligent Optimization Method For Tunnel Rotary Drilling Based On Drill String Status Estimation, Yao Ningping, Wei Hongchao, Zhang Jinbao, Lu Chengda, Li Hao, Yao Yafeng, Ke Yougang, Zhang Youzhen Nov 2023

Intelligent Optimization Method For Tunnel Rotary Drilling Based On Drill String Status Estimation, Yao Ningping, Wei Hongchao, Zhang Jinbao, Lu Chengda, Li Hao, Yao Yafeng, Ke Yougang, Zhang Youzhen

Coal Geology & Exploration

To address the issue in existing research where it is difficult to obtain bottom-hole drilling parameters while drilling, and to overcome the problem of low accuracy and insufficient improvement when optimizing rotary drilling operational parameters using only borehole data, an intelligent optimization method for near-horizontal tunnel rotary drilling based on drill string status is proposed. This involves constructing an in-hole state observer to estimate bottom-hole drilling parameter information. Firstly, the characteristics of rotary drilling in underground coal mine tunnels are analyzed, considering the constraints of actual drilling, and an optimization target evaluation method for mechanical drilling speed and drill bit …


Rate-Of-Penetration (Rop) Prediction Model Based On Formation Characteristics Of Extremely Thick Plastic Mudstone In South China Sea, Zeng Xiaolong, Li Qian, Wei Hongchao, Chen Jiahao, Zhu Haiyan Nov 2023

Rate-Of-Penetration (Rop) Prediction Model Based On Formation Characteristics Of Extremely Thick Plastic Mudstone In South China Sea, Zeng Xiaolong, Li Qian, Wei Hongchao, Chen Jiahao, Zhu Haiyan

Coal Geology & Exploration

In terms of petroleum and gas resources, South China Sea is the important energy replacement area in China. However, most of the reservoirs are buried deep, and the strong plasticity of the formation under high confining pressure and the complex geological environment seriously affect the drilling efficiency. It is also very difficult to accurately predict the ROP. Hence, a set of intelligent ROP prediction model was established for the extremely thick mudstone formation with unique viscoelastic and strong plastic characteristics in South China Sea. The model took the actual data of 10 wells in an area of South China Sea …


Compressibility Behavior Of Conditioned Sandy Clay Considering The Physical Degradation Of Foam: Tunneling Issue, Mœz Selmi, Yahya Alassaf, Mariem Kacem, Mehrez Jamei Nov 2023

Compressibility Behavior Of Conditioned Sandy Clay Considering The Physical Degradation Of Foam: Tunneling Issue, Mœz Selmi, Yahya Alassaf, Mariem Kacem, Mehrez Jamei

Journal of Sustainable Mining

Surfactants in the form of liquid foam are commonly used for ensuring the fluidity of conditioned soil during shield tunneling in mining zone. The compressibility can be significantly affected, depending on the percentage of fine soil. Thus, this paper investigates the compressibility of foam-conditioned fine soil. Oedometric tests as a function of the percentage of foam have been performed. Foam’s stability was analyzed, considering a laboratory soil made from 40% kaolinite and 60% of sand and mixed with a foaming agent based on an anionic surfactant. Experimental results showed that the foam stability was manifested through a reduction of the …


Ventilation Of Tunnels During Drilling Using A Forcing Ventilation System – A Case Study, Krzysztof Słota, Zbigniew Słota Oct 2023

Ventilation Of Tunnels During Drilling Using A Forcing Ventilation System – A Case Study, Krzysztof Słota, Zbigniew Słota

Journal of Sustainable Mining

In Poland, more and more tunnels are being built using mining methods. Mostly ventilation systems are described for tunnels already commissioned. There are few examples of ventilation calculations for tunnels under construction. The paper shows a case study where calculations were made of the minimum air volume flow required to ventilate a tunnel during its tunnelling using four duct ventilation systems. The first system used two separate fans with a 1200 mm diameter duct line, the second system changed the diameter of the duct line to 1400 mm, the third system used one fan with two 1200 mm diameter duct …


Influence Of Explosive Maximum Instantaneous Charge On Blasting Environmental Impact, Olukemi Yetunde Odeyemi, Blessing Olamide Taiwo, Olarewaju Alaba Oct 2023

Influence Of Explosive Maximum Instantaneous Charge On Blasting Environmental Impact, Olukemi Yetunde Odeyemi, Blessing Olamide Taiwo, Olarewaju Alaba

Journal of Sustainable Mining

Our research looked at the effect of explosive maximum instantaneous charge on ground vibrations and noise levels during blasting operations at the Calaba limestone quarry in Nigeria. Vibrock (V9000) seismograph was used to take readings related to ground vibrations and noise generated during all blasting operations that took place in the quarry for a period of one year. The results obtained indicate that the average ground vibration readings fall between 0.25mm/s to 3.6mm/s and the average noise decibel generated during the blasting operations between 35 to 158 dB. An artificial neural network (ANN) model is developed in this study for …


A New Physics-Informed Method For The Fracability Evaluation Of Shale Oil Reservoirs, Li Yuwei, Li Zijian, Shao Lifei, Tian Fuchun, Tang Jizhou Oct 2023

A New Physics-Informed Method For The Fracability Evaluation Of Shale Oil Reservoirs, Li Yuwei, Li Zijian, Shao Lifei, Tian Fuchun, Tang Jizhou

Coal Geology & Exploration

The accurate evaluation of reservoir fracability is an essential prerequisite for the fracturing design and post-fracturing productivity evaluation of reservoirs. Rock mechanical parameters have been applied to the fracability evaluation of shales presently, exhibiting great field application performance. Accordingly, it is crucial to obtain accurate rock mechanical parameters. This study developed a physics-informed neural network (PINN) model. Driven by data and physical information, the PINN model can accurately predict rock mechanical parameters using only a small amount of data. To verify its performance, the PINN model was compared with the artificial neural network, random forest, and XGBoost models. The comparison …


An Attention Mechanism-Based Cnn-Bilstm Real-Time Transient Electromagnetic Method, Gu Yao, Xie Haijun, Zhou Zipeng, Li Lu Oct 2023

An Attention Mechanism-Based Cnn-Bilstm Real-Time Transient Electromagnetic Method, Gu Yao, Xie Haijun, Zhou Zipeng, Li Lu

Coal Geology & Exploration

The one-dimensional transient electromagnetic (TEM) method is time-consuming and suffers other drawbacks such as difficult parameter adjustment and heavy dependence on the initial model. Therefore, this study proposed a real-time TEM inversion method—the Attention mechanism-based convolutional neural network (CNN) - bidirectional Long Short-Term Memory (BiLSTM) (AC-BiLSTM). By fully utilizing the time difference, the AC-BiLSTM performed model training in non-observation time and the real-time inversion of the collected data in observation time. With the measured data mixed with a certain proportion of data obtained from forward modeling as the dataset, the sampling time and apparent resistivity as the input features in …


Research Progress Of Rotary Steerable System And Its Control Methods, Li Wei, Mou Lei, Zhou Xiancheng, Tan Xianhui, Fu Quan Oct 2023

Research Progress Of Rotary Steerable System And Its Control Methods, Li Wei, Mou Lei, Zhou Xiancheng, Tan Xianhui, Fu Quan

Coal Geology & Exploration

Rotary steerable system is a shining pearl in directional drilling technology and an important technical means to realize the low-cost and efficient development of oil and gas resources. First of all, the basic structure of the rotary steerable system was introduced. According to the different steering modes and bias effects, the rotary steerable system is divided into five categories: static push-the-bit type, dynamic push-the-bit type, static pointing type, dynamic point-the-bit type and mixed type, for which the steering principle was analyzed one by one. Secondly, according to the research and application of rotary steerable system technology at home and abroad, …


Table Of Contents, The Editors Oct 2023

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Gas Expansion Energy Of Coals With Different Metamorphic Degrees: Evolutionary Characteristics And Their Implications For The Outburst Prediction, Liu Gaofeng, Li Baolin, Zhang Zhen, Liu Huan, Guan Wenbo, Si Nian Oct 2023

Gas Expansion Energy Of Coals With Different Metamorphic Degrees: Evolutionary Characteristics And Their Implications For The Outburst Prediction, Liu Gaofeng, Li Baolin, Zhang Zhen, Liu Huan, Guan Wenbo, Si Nian

Coal Geology & Exploration

To achieve an elevated accuracy in the prediction of coal and gas outbursts, this study conducted mercury injection capillary pressure (MICP) tests and isotherm adsorption experiments on selected six coal samples with different metamorphic degrees. Furthermore, it calculated the gas expansion energy of coals and analyzed the evolutionary characteristics of the gas expansion energy of coals with different metamorphic degrees, as well as their relationships with the prediction indices of coal and gas outbursts. The results of this study are as follows: (1) The differences in the pore structures and adsorptivity of coals with different metamorphic degrees led to different …


Water-Blocking Performance Of Laterite In Weak Deposition Areas Of Neogene Baode Formation And Its Significance Of Resource Exploitation, Zeng Yifan, Bao Han, Wu Qiang, Meng Shihao, Hua Zhaolai, Miao Yanping, Zhang Ye, Bu Wenyang Oct 2023

Water-Blocking Performance Of Laterite In Weak Deposition Areas Of Neogene Baode Formation And Its Significance Of Resource Exploitation, Zeng Yifan, Bao Han, Wu Qiang, Meng Shihao, Hua Zhaolai, Miao Yanping, Zhang Ye, Bu Wenyang

Coal Geology & Exploration

The in-depth study on the water-blocking performance of laterite in the weak deposition areas of the key aquiclude is of significant importance for mine production safety and ecological water resource protection. Specifically, the borehole data were re-optimized based on the regional sedimentary characteristics, the thickness distribution pattern of laterite deposit in Yushen mining area was studied, and the micro-engineering characteristics and control factors related to the water-blocking performance of laterite were explored. The results show that the deposition thickness of laterite gradually increases from northwest to southeast, the distribution of laterite becomes extremely uneven with the evolution of rivers, and …


Prediction Of Rockburst Intensity Grade Based On Convolutional Neural Network, Li Kangnan, Wu Yaqin, Du Feng, Zhang Xiang, Wang Yiqiao Oct 2023

Prediction Of Rockburst Intensity Grade Based On Convolutional Neural Network, Li Kangnan, Wu Yaqin, Du Feng, Zhang Xiang, Wang Yiqiao

Coal Geology & Exploration

Rockburst is one of the urgent problems to be addressed in the process of deep resource extraction. In order to predict the rockburst disasters safely and efficiently, a rockburst intensity grade prediction model (MICE-CNN) based on the Multiple Imputation by Chained Equations (MICE) and Convolutional Neural Network (CNN) was proposed. Specifically, a predictive indicator system was established based on the main influencing factors and the acquisition conditions of rockburst. A total of 120 sets of raw data from rockburst cases were collected, with the outliers processed by pauta criterion. Then, the missing data were interpolated with the four interpolation models …


Status And Development Of Intelligent Drilling Tools For Coal Mine, Gao Xiaoliang Oct 2023

Status And Development Of Intelligent Drilling Tools For Coal Mine, Gao Xiaoliang

Coal Geology & Exploration

As an important part of intelligent drilling, the intelligence of drilling tool system plays a crucial role in the intelligent development of coal mine underground drilling. In order to deeply explore the development direction of intelligent drilling tools, the research results and technical characteristics of intelligent drilling tools in coal mines were systematically sorted out from the aspects of directional drilling tools, measurement while drilling (MWD) system, intelligent drilling pipes and drill bits with reference to the experience in development of oil and gas industry, and the existing shortcomings were also summarized. It is pointed out that screw motor is …


Methods For Estimating Carbon Emissions From Coals In Underground Mines: A Case Study Of The Western Fukang Mining Area, Peng Rendong, Wei Bo, Li Xin, Zhang Ji, Zhang Zizhao, Wang Bo, Zhang Na, Cui Deguang Oct 2023

Methods For Estimating Carbon Emissions From Coals In Underground Mines: A Case Study Of The Western Fukang Mining Area, Peng Rendong, Wei Bo, Li Xin, Zhang Ji, Zhang Zizhao, Wang Bo, Zhang Na, Cui Deguang

Coal Geology & Exploration

Carbon emissions have come into sharp focus of human society. The carbon emissions from coals rank as the most predominant part of China’s total carbon emissions. Presently, there is no available study on the accurate calculation of carbon emissions from coals in typical underground mines in Xinjiang, with the CH4 emission even overlooked. This study centers on the carbon emissions from coals in underground mines in the western Fukang mining area. As per the occurrence laws of CH4 and CO2 in coal seams, as well as coal mining plans, this study classified the sources of carbon emissions …


A Method For Identifying Faults Within Mining Faces Based On Spatial Statistics, Feng Yajie, Wen Guangchao, Wu Bingjie, Hu Zudong Oct 2023

A Method For Identifying Faults Within Mining Faces Based On Spatial Statistics, Feng Yajie, Wen Guangchao, Wu Bingjie, Hu Zudong

Coal Geology & Exploration

Minor faults within mining faces of coal mines severely affect gas drainage and coal seam mining. Accurately identifying parameters such as positions, throws, and attitudes of these faults is of great significance for the safe production of coal mines. To effectively reduce gas emissions, prevent gas explosions, and exploit and utilize gas resources, many gas drainage holes have been drilled during the construction of coal mines, providing favorable engineering conditions for identifying minor faults within coal seams. Compared with the conventional fault identification methods, which rely on the expertise of geologists, the identification model based on mathematical statistics and space …


An Improved Automated Testing Model For Maceral Groups In Coals Based On Deeplabv3+, Hu Jinwei, Xi Zhenghao, Xu Guozhong, Li Zhongfeng, Liu Xiang Oct 2023

An Improved Automated Testing Model For Maceral Groups In Coals Based On Deeplabv3+, Hu Jinwei, Xi Zhenghao, Xu Guozhong, Li Zhongfeng, Liu Xiang

Coal Geology & Exploration

The identification of maceral groups in coals plays a critical role in analyzing the chemical properties of coals. However, manual identification is laborious and requires high expertise. Existing computer-assisted identification methods, mostly adopting deep learning-based semantic segmentation models, fail to accurately identify maceral groups in coals due to complex compositions of microscopic coal images and the presence of transitional components. Therefore, this study proposed an improved DeeplabV3+ semantic segmentation model integrating the Swin Transformer backbone network and the SkNet. First, to deal with the challenge of feature extraction caused by the intertwined maceral groups and the presence of transitional components …


Discovery And Generation Mechanisms Of Epigenetic Biogenic H2S From Coal Seams In The Fukang Block, Southern Junggar Basin, China, Yan Peipei, Su Xianbo, Zou Chenglong, Zhao Weizhong, Wang Lufei, Fu Haijiao Oct 2023

Discovery And Generation Mechanisms Of Epigenetic Biogenic H2S From Coal Seams In The Fukang Block, Southern Junggar Basin, China, Yan Peipei, Su Xianbo, Zou Chenglong, Zhao Weizhong, Wang Lufei, Fu Haijiao

Coal Geology & Exploration

In the Fukang block located in the eastern part of the southern Junggar Basin, coalbed methane (CBM) from CBM wells exhibits a gradually increasing H2S concentration in the process of CBM production via water drainage, severely threatening production safety. Based on the CBM exploration and extraction data, as well as the anaerobic fermentation experiments, this study preliminarily investigated the causes of abnormal H2S concentrations during the CBM production in the Fukang block. As indicated by the gas content test in the CBM exploration stage, the original CBM showed a low H2S concentration of only …


Pfc Numerical Analysis On Crack Initiation Mechanism Of Fracture Grouting In Top Of Ordovician Limestone, Liu Zhaoxing, Zhang Qi Oct 2023

Pfc Numerical Analysis On Crack Initiation Mechanism Of Fracture Grouting In Top Of Ordovician Limestone, Liu Zhaoxing, Zhang Qi

Coal Geology & Exploration

The advanced regional grouting is an effective means to prevent and control the water hazard of limestone in coal seam floor, and the fracture grouting projects is a key link to determine the effect of the grouting in floor against water hazard. However, due to the unclear understanding of the fracture initiation mechanism of the injected limestone stratum, the grouting pressure, grout water-cement ratio and other grouting parameters in the process of fracture grouting are not effectively controlled. Thus, it is difficult to guarantee the grouting effect. In order to solve the above problems, numerical simulation calculation was conducted for …


Water Inrush Mechanism Of Coal Mine Shaft Fracture Under Fluid-Solid Coupling, Xue Weipei, Shen Lei, Yao Zhishu, Cheng Hua, Rong Chuanxin Oct 2023

Water Inrush Mechanism Of Coal Mine Shaft Fracture Under Fluid-Solid Coupling, Xue Weipei, Shen Lei, Yao Zhishu, Cheng Hua, Rong Chuanxin

Coal Geology & Exploration

The occurrence of coal mine shaft fractures and water inrush accidents is alarmingly frequent, endangering the lives of underground personnel and compromising mine safety. To comprehend the influence of confined groundwater in the process of shaft fracture and the formation mechanism of water inrush channels, a model test was devised using similarity theory and coupled fluid-solid numerical simulation technology. The findings reveal that direct contact between the shaft lining and pressurized water hinders the development of load-bearing and deformation capacities. This is specifically evidenced by the premature appearance of the yield point, a reduction in peak strength and strain, and …


Zoned Prediction Of Water Inflow After Dewatering Of Working Face Based On Waterrichness Zoning Of Aquifer, Yang Lei, Lei Fangchao, Hou Enke, Lu Bo, Feng Dong, Zhao Kaixing Oct 2023

Zoned Prediction Of Water Inflow After Dewatering Of Working Face Based On Waterrichness Zoning Of Aquifer, Yang Lei, Lei Fangchao, Hou Enke, Lu Bo, Feng Dong, Zhao Kaixing

Coal Geology & Exploration

As the weathered bedrock and burned rock aquifers seriously threaten the production safety of mines in the Jurassic coalfield of northern Shaanxi Province, accurate prediction of their waterrichness and water inflow at the working face is of great significance for water control in mines. Aiming at the weathered bedrock and burned rock aquifers with close hydraulic connection, the area where working face 15217 of Shaanxi Hongliulin Coal Mine is located was taken as the study area. Meanwhile, the aquifer thickness, lithological combination index, index of rock burning and weathering degree and core recovery was taken as the evaluation indexes. The …


Numerical Model Of Two-Region Flow By Constant-Head Pumping In An Unconfined Aquifer, Shi Pengyu, Zong Yijie, Teng Kaiqing, Liu Jianjun, Xiao Liang Oct 2023

Numerical Model Of Two-Region Flow By Constant-Head Pumping In An Unconfined Aquifer, Shi Pengyu, Zong Yijie, Teng Kaiqing, Liu Jianjun, Xiao Liang

Coal Geology & Exploration

In order to reveal the mechanism of two-region Darcian and non-Darcian flow induced by constant-head pumping tests in unconfined aquifers, a numerical model of well flow by constant-head pumping underground based on finite difference solution was proposed. In the model, it is assumed that the aquifer is divided into two regions according to the pumping flow characteristics: the finite non-Darcian flow region near the pumping well and the semi-infinite Darcian flow region far away from the pumping well. Specifically, the flow regime in the non-Darcian flow region was simulated by the Izbash’s equation, and the reliability of the proposed solution …


Study On Mesoscopic Failure Characteristics Of Layered Red Shale, Ma Zhenqian, Zhou Lang, Zuo Yujun, Zhang Jimin, Zou Yihuai, Cao Yunqin Oct 2023

Study On Mesoscopic Failure Characteristics Of Layered Red Shale, Ma Zhenqian, Zhou Lang, Zuo Yujun, Zhang Jimin, Zou Yihuai, Cao Yunqin

Coal Geology & Exploration

To study the mesoscopic failure characteristics of the layered red shale, uniaxial mechanical experiments were carried out by applying DSTD-1000 electro-hydraulic servo rigid pressure on the red shale with different bedding angles. Meanwhile, SEM and XRD experiments were implemented on debris to obtain its mechanical parameters, failure characteristics, microstructure, and relative content of components. Based on this, models of the red shale with different bedding angles were constructed using the discrete element PFC3D for the uniaxial compression experiments to study the mesoscopic failure characteristics of red shale. The results show that: (1) When the bedding angle θ=30°, 45°, …


Numerical Simulations And Wavefield Analysis Of In-Seam Wave Advance Detection In Viscoelastic Media, He Dixiu, Ji Guangzhong, Jiao Wenjie, Zhang Yawei, Yu Kun Oct 2023

Numerical Simulations And Wavefield Analysis Of In-Seam Wave Advance Detection In Viscoelastic Media, He Dixiu, Ji Guangzhong, Jiao Wenjie, Zhang Yawei, Yu Kun

Coal Geology & Exploration

In-seam waves are commonly applied to the advance detection of hidden faults in front of mining faces. However, coal seams, which have viscoelasticity actually, imposing absorptive and attenuation effects on in-seam waves. To investigate the wave field characteristics and propagation patterns of in-seam waves in viscoelastic coal seam media, this study built a three-dimensional geological model of coal measures with faults based on Kelvin-Voigt’s first-order velocity-stress equation. Using this equation, three-dimensional finite-difference numerical simulation was carried out. The results indicate that (1) for reflected in-seam waves in viscoelastic media, which exhibit high energy attenuation, their propagation and attenuation characteristics are …


Manipulator Trajectory Planning Method Of Anchor Drilling Robot, Lei Mengyu, Zhang Xuhui, Yang Wenjuan, Dong Zheng, Wan Jicheng, Zhang Chao, Du Yuyang Oct 2023

Manipulator Trajectory Planning Method Of Anchor Drilling Robot, Lei Mengyu, Zhang Xuhui, Yang Wenjuan, Dong Zheng, Wan Jicheng, Zhang Chao, Du Yuyang

Coal Geology & Exploration

In order to improve the support efficiency of coal mine roadway and the automation intelligence of heading face, an anchor drilling robot integrating the cantilever roadheader and the six-degree-of-freedom manipulator was designed, and studied on the anchor drilling sequence planning strategy and the drilling boom trajectory planning method. Firstly, the kinematics model of the manipulator structure was established based on the improved DH method. On this basis, the forward and inverse kinematics solutions were analyzed, and the spatial position and the corresponding joint variable values of the drilling rig were calculated. Secondly, the manipulator space was analyzed based on Monte …