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Full-Text Articles in Engineering

Research Progress On Variation Pattern And Monitoring Control Technology Of Negative Pressure For Gas Drainage In Directional Long Borehole, Li Quanxin, Cheng Zhuoer, Fang Jun, Mou Quanbin, Liu Fei, Cong Lin Nov 2024

Research Progress On Variation Pattern And Monitoring Control Technology Of Negative Pressure For Gas Drainage In Directional Long Borehole, Li Quanxin, Cheng Zhuoer, Fang Jun, Mou Quanbin, Liu Fei, Cong Lin

Coal Geology & Exploration

Significance Near-horizontal directional long borehole is an important technical approach and effective means for preventing and controlling the gas disasters of coal mine. Negative pressure is an important factor affecting the gas drainage effect of directional long borehole. Advances Herein, the research progress on gas drainage through near-horizontal directional long borehole was systematically summarized from three aspects: the attenuation mechanism and distribution law of negative pressure in the borehole, gas drainage parameter monitoring technology, and intelligent control system for gas drainage. Regarding the attenuation mechanism and distribution law of negative pressure in the borehole, the basic theoretical research results concerning …


Fine And Intelligent Interpretation Of Key Geological Structures In The Metal Metallogenesis Of Coal Measures, Yang Yi, Zhao Jingtao, Li Wenyu, Shi Suzhen Nov 2024

Fine And Intelligent Interpretation Of Key Geological Structures In The Metal Metallogenesis Of Coal Measures, Yang Yi, Zhao Jingtao, Li Wenyu, Shi Suzhen

Coal Geology & Exploration

Objective In order to identify the key geological structures in the metallogenic process of coal measures metal deposits, the Linxing block of Ordos Basin was taken as the research object. Based on the previous research results, geological data of the block, seismic and logging data, a geological model including tectonic volcanic activities and other events was constructed to analyze the key geological factors of deposit formation. Methods Firstly, based on the post-stack seismic data, the diffraction wave separation and imaging are realized by using the plane wave destruction filter technology, and the small-scale key geological information is extracted. Secondly, the …


Techniques For Coal Resource Conservation During The Ecological Restoration Of Alpine Mining Areas On Plateaus, Li Congcong, Wang Tong, Zhao Xin, Wang Weichao, Liang Zhenxin Nov 2024

Techniques For Coal Resource Conservation During The Ecological Restoration Of Alpine Mining Areas On Plateaus, Li Congcong, Wang Tong, Zhao Xin, Wang Weichao, Liang Zhenxin

Coal Geology & Exploration

Objective The prolonged coal mining of the Muli coalfield, located in an alpine region in the eastern Qinghai-Tibet Plateau, has posed many ecological challenges, which especially include the presence of considerable quantities of disturbed coal resources in open-pit mining areas. This study aims to achieve scientific and effective coal resource conservation during the ecological restoration of coal mines. Methods Focusing on the Jvhugeng mining area of the Muli coalfield, this study investigated the destruction characteristics of the coal resources in the open-pit mining area. From the perspective of geological mechanisms behind the destruction, this study artificially constructed the roofs of …


3d Reconstruction Of Surface Temperature Field In Spontaneous Combustion Coal Gangue Dump Fire Area And Its Practice, Shao Zhenlu, Zhang Huisong, Deng Rong, Yang Tong, Ma Dong Nov 2024

3d Reconstruction Of Surface Temperature Field In Spontaneous Combustion Coal Gangue Dump Fire Area And Its Practice, Shao Zhenlu, Zhang Huisong, Deng Rong, Yang Tong, Ma Dong

Coal Geology & Exploration

Objective The spontaneous combustion of coal gangue dumps has severely damaged the ecological environment and affected the production safety, which has become a bottleneck in the process of ecological civilization construction in China. In order to formulate a fire extinguishing plan and implement a fire extinguishing project, it is very important to accurately detect the fire area of the spontaneous combustion coal gangue dump. Methods Herein, the idea of detecting the three-dimensional distribution of high-temperature areas using unmanned aerial vehicle (UAV) based thermal infrared oblique photogrammetry technology was proposed. Meanwhile, the multi-scale Gaussian filtering detail enhancement technology for thermal infrared …


Detrital Zircon Ages Of The Permian Coal-Bearing Rock Series In The Zhongtiao Mountain Area And Their Sedimentological Constraints On Regional Tectonic Activity, Wu Fang, Li Zhenhong, Jing Xianghui, Kou Linlin, Du Zhuang, Liu Bohua Nov 2024

Detrital Zircon Ages Of The Permian Coal-Bearing Rock Series In The Zhongtiao Mountain Area And Their Sedimentological Constraints On Regional Tectonic Activity, Wu Fang, Li Zhenhong, Jing Xianghui, Kou Linlin, Du Zhuang, Liu Bohua

Coal Geology & Exploration

Objective The changes in the material composition of detrital sediments in a sedimentary basin are intimately associated with the uplift and denudation processes of provenance areas. The southern margin of the North China Craton, a primary tectonic unit of the continental area of China, preserves relatively complete geological records of the Permian. The Zhongtiao Mountain area is located in the core of the Fen-Wei graben system on the southern margin of the North China Craton, with the southern margin of the North China Craton and the adjacent Qinling orogenic belt potentially serving as its provenance areas. Therefore, the Zhongtiao Mountain …


A Smogn-Based Mpso-Bp Model To Predict The Height Of A Hydraulically Conductive Fracture Zone, Liu Qi, Liang Zhihao, Zi Jianxiao Nov 2024

A Smogn-Based Mpso-Bp Model To Predict The Height Of A Hydraulically Conductive Fracture Zone, Liu Qi, Liang Zhihao, Zi Jianxiao

Coal Geology & Exploration

Objective The height of a hydraulically conductive fracture zone, a significant factor influencing roof water inrushes and groundwater resource loss, is identified as a research focus of the prevention and control of mine water disasters. Methods To accurately predict the heights of hydraulically conductive fracture zones in coal seam roofs, five parameters were selected as the primary factors influencing hydraulically conductive fracture zones the mining depth: mining height, coal seam inclination, the length of the mining face along its dip direction, proportional coefficient of hard rocks (i.e., the ratio of the cumulative thickness of hard rocks within the statistical height …


Acoustic Velocity Inversion Based On Convolutional Autoencoder Embedded With Fourier Neural Operator, Li Chen, Zhao Haixia, Bai Zhaowei, Hao Yufan Nov 2024

Acoustic Velocity Inversion Based On Convolutional Autoencoder Embedded With Fourier Neural Operator, Li Chen, Zhao Haixia, Bai Zhaowei, Hao Yufan

Coal Geology & Exploration

Background Seismic wave inversion serves as an effective method for obtaining the characteristics of structures, lithology, and physical properties of subsurface media using the arrival times, amplitude, and waveforms of seismic waves. Seismic inversion methods based on wave equations iteratively update model parameters using forward modeling. This generally involves extensive numerical simulations and optimization calculations, requiring large quantities of computational resources and time. In recent years, neural operators for deep learning, represented by the Fourier neural operator (FNO), have gained widespread attention. However, the original FNO structure fails to effectively learn the wavefield information with sharp changes in geological structures …


Intelligent Noise Suppression For 3d Post-Stack Seismic Data Of The Junggar Basin, Mao Haibo, Zhou Xin, Li Xiaofeng, Pan Long, Lin Juan, Liu Dawei, Wang Xiaokai Nov 2024

Intelligent Noise Suppression For 3d Post-Stack Seismic Data Of The Junggar Basin, Mao Haibo, Zhou Xin, Li Xiaofeng, Pan Long, Lin Juan, Liu Dawei, Wang Xiaokai

Coal Geology & Exploration

Objective The Junggar Basin is recognized as a significant petroliferous basin in China, and its hydrocarbon exploration targets have shifted to deeper strata. However, the 3D seismic data of this basin suffer from low signal-to-noise ratios (SNRs) and high data volumes due to the basin's complex near-surface conditions, the great depths of exploration targets, and seismic data acquisition methods characterized by wide azimuths, broadbands, and high density. This complicates the identification of hydrocarbon exploration targets, rendering the improvement in the quality of the 3D seismic data by noise suppression vitally important. Methods The progress in the deep learning theory and …


Transient Electromagnetic Numerical Simulation Based On The Transformer Neural Network, Wang Yunhong Nov 2024

Transient Electromagnetic Numerical Simulation Based On The Transformer Neural Network, Wang Yunhong

Coal Geology & Exploration

Objective The deep learning-based transient electromagnetic (TEM) forward and inverse modeling methods are data-driven, requiring considerable numerical simulation results as supervisory data to train and assess neural networks. The conventional finite-difference time-domain (FDTD) method for TEM numerical simulation necessitates an iterative solution of time-domain Maxwell's equations. Therefore, this method is time-consuming and computationally intensive, failing to meet the data demand of deep learning-based TEM inversion. Methods This study introduced deep learning for TEM numerical simulation. Based on the transformer neural network architecture, a neural network for deep learning-based TEM numerical simulation was designed using an encoder-decoder structure. This neural network …


Surfaced-Related Multiple Attenuation Using The Cnn Method In The Nmo Domain, Huang Zhufu, Liu Jianfeng, Fang Wenqian, Fu Lihua Nov 2024

Surfaced-Related Multiple Attenuation Using The Cnn Method In The Nmo Domain, Huang Zhufu, Liu Jianfeng, Fang Wenqian, Fu Lihua

Coal Geology & Exploration

Objective The presence of surface-related multiples results in a lower accuracy in seismic data interpretations, and the effective multiple attenuation is a key step in seismic data processing. Multiples are coherent noise signals with similar characteristics to effective signals. It is difficult impossible to distinguish multiple signals from full-wave field data using a traditional convolutional neural network (CNN). Additionally, since the surface-related multiples vary significantly with surveyed areas, the CNN method will face more severe challenges when being transferred to other networks. Methods This study developed a CNN method based on the normal moveout correction (NMO) domain by introducing physical …


Impacts And Regulation Mechanisms Of Phase-Change Wall Microspheres On Cement Slurry Performance In Well Cementing, Zheng Mingming, Wu Zurui, Yan Shichun, Hu Yunpeng, He Juan, Zhang Yawei, Xiong Liang, Zhu Chengtao Nov 2024

Impacts And Regulation Mechanisms Of Phase-Change Wall Microspheres On Cement Slurry Performance In Well Cementing, Zheng Mingming, Wu Zurui, Yan Shichun, Hu Yunpeng, He Juan, Zhang Yawei, Xiong Liang, Zhu Chengtao

Coal Geology & Exploration

Objective The current design of low-heat cement slurries prepared by adding microspheres with phase change materials as wall materials for well cementing in strata bearing natural gas hydrates (NGHs) fails to fully account for the impacts of the particle size and mass fraction of the microspheres on the performance of cement slurries. This leads to impaired cement slurry performance and increased costs, further inducing many problems with well cementing quality. Hence, it is significant to analyze the impacts and controlling mechanisms of the microspheres on cement slurry performance. Methods To eliminate the interference of the heat storage effect of the …


An Intelligent Identifying-While-Drilling Method For Geological Features Of Roof Strata In Coal Roadways Based On A 1dcnn-Bilstm-Cbam Model, Lei Zhiyong, Wang Jiawen, Fan Dong, Lu Feifei, Chen Weiming Nov 2024

An Intelligent Identifying-While-Drilling Method For Geological Features Of Roof Strata In Coal Roadways Based On A 1dcnn-Bilstm-Cbam Model, Lei Zhiyong, Wang Jiawen, Fan Dong, Lu Feifei, Chen Weiming

Coal Geology & Exploration

Objective Most roof accidents in coal roadways occur in potential caving zones such as primary fissure-bearing zones and rock fracture zones. A significant approach to preventing roof accidents is to understand the geological features of roof strata in an accurate and timely manner and optimize support schemes and parameters of roofs. However, current methods for identifying the geological features of roof strata in roadways suffer from issues such as slow identification speeds, low efficiency, and high costs, thus failing to meet the demand for safe, efficient, and intelligent coal mining. Methods This study proposed a neural network model based on …


Rock Burst Hazard Evaluation Of Coal Mining Face Based On A Gaussian Mixture Model, Cui Feng, Li Yifei, Jia Chong, Lu Changliang, He Shifeng, Zhang Suilin, Tian Mengqi Oct 2024

Rock Burst Hazard Evaluation Of Coal Mining Face Based On A Gaussian Mixture Model, Cui Feng, Li Yifei, Jia Chong, Lu Changliang, He Shifeng, Zhang Suilin, Tian Mengqi

Coal Geology & Exploration

Objective Deep insights into the probabilistic information contained in the energy distribution of acoustic emission (AE) or microseismic events are significant for the rock burst hazard evaluation of coal mining face. Methods This study investigated No.40111 mining face of the No.4 coal seam at the Dafosi Coal Mine in Shaanxi Province. Using physical simulation experiments with similar materials, theoretical analysis, and on-site monitoring, this study investigated the evolutionary patterns of AE monitoring data during coal mining and illustrated the physical meaning of fluctuations in the probability distribution of AE energy. Accordingly, this study proposed an index model for the rock …


Advances In Research On The Evolution Of Trans-Scale Discontinuous Structures During The Creeps Of Strongly Disturbed Coals, Zhang Liang, Wang Laigui, Ren Ting, Li Xiangchun, Gao Ke, Li Haitao, Zhao Shankun Oct 2024

Advances In Research On The Evolution Of Trans-Scale Discontinuous Structures During The Creeps Of Strongly Disturbed Coals, Zhang Liang, Wang Laigui, Ren Ting, Li Xiangchun, Gao Ke, Li Haitao, Zhao Shankun

Coal Geology & Exploration

Objective and Methods Disasters associated with surrounding rocks in roadways, such as time-dependent deformation failure and creep-induced rock bursts, severely threaten deep mines in China. These disasters, coupled with the impacts of deep mining and structural changes, render it urgent to explore the evolutionary patterns of trans-scale discontinuous structures during the creeps of strongly disturbed coals. This study systematically reviews the scale effects of coals' mechanical properties, the discontinuous structures and multi-physics field effects of coals, and the long-term stability, creep evolutionary patterns, and mechanical models of coals. It highlights the close correlation between discontinuous structures (including their fractures and …


Sedimentary Environments, Mechanical Properties, And Rock Burst Risk Identification Of Overburden In Deep Mines, Qiao Wei, Cheng Xianggang, Dou Linming, He Hu, Meng Xiangsheng, Ren Yangyang, Xiao Chong, Cai Jin Oct 2024

Sedimentary Environments, Mechanical Properties, And Rock Burst Risk Identification Of Overburden In Deep Mines, Qiao Wei, Cheng Xianggang, Dou Linming, He Hu, Meng Xiangsheng, Ren Yangyang, Xiao Chong, Cai Jin

Coal Geology & Exploration

Objective Disaster risk identification and prediction serve as a prerequisite for disaster control. An engineering geological environment is identified as the fundamental condition inducing dynamic disasters like rock bursts in mines. Exploring the sedimentary genetic mechanisms of engineering geological environments holds great significance for predicting rock burst risks. Methods With the Gaojiapu Coal Mine in the Binchang mining area, Shaanxi Province, as a case study, this study analyzed the engineering geological characteristics of rock masses under different sedimentary microfacies. Furthermore, it explored the deformation and failure characteristics of rocks in different sedimentary environments, along with the energy release patterns of …


An Experimental Study Of The Evolutionary Patterns Of Mechanical Properties Of Coals Under Multiple Mining Disturbances, Ouyang Zhenhua, Liu Yang, Li Chunlei, Shi Qingwen, Li Wenshuai, Yi Haiyang, Qin Hongyan, Zhang Ningbo Oct 2024

An Experimental Study Of The Evolutionary Patterns Of Mechanical Properties Of Coals Under Multiple Mining Disturbances, Ouyang Zhenhua, Liu Yang, Li Chunlei, Shi Qingwen, Li Wenshuai, Yi Haiyang, Qin Hongyan, Zhang Ningbo

Coal Geology & Exploration

Objective In the mining process of coal mines, the cyclic loading and unloading effects caused by multiple mining disturbances can alter the mechanical properties of coals, serving as a significant cause of rock bursts. Revealing the response characteristics of crucial mechanical parameters and the damage mechanisms of coals can provide a basis for discriminating the impact-induced instability state, holding great significance for enhancing disaster prediction capabilities. Methods Quasi-static uniaxial cyclic loading and unloading experiments and the dynamic impact loading experiments on large-size coal-like specimens were combined to accurately capture the stress, strain, and acoustic emission responses during the experiments, thoroughly …


Exploring The Evolutionary Patterns Of Stress Field In Coal Seams During Water Drainage In Overburden Confined Aquifers Based On Charge Monitoring, Wang Gang, Yu Xiaojie, Wang Aiwen, Xiao Xiaochun, Wang Yong, Ding Xin, Wang Weibin, Xu Zengjun, Du Lulu Oct 2024

Exploring The Evolutionary Patterns Of Stress Field In Coal Seams During Water Drainage In Overburden Confined Aquifers Based On Charge Monitoring, Wang Gang, Yu Xiaojie, Wang Aiwen, Xiao Xiaochun, Wang Yong, Ding Xin, Wang Weibin, Xu Zengjun, Du Lulu

Coal Geology & Exploration

Objective Deep coal mining areas in regions such as Inner Mongolia, Shaanxi, Shandong, and Gansu in China feature intricate hydrogeological conditions, which lead to substantial water drainage from roofs and increasingly prominent rock bursts induced by water drainage in overburden confined aquifers. This study investigated the evolutionary patterns of the stress field in coal seams during the water drainage of overburden confined aquifers. Methods By combining the laboratory charge induction experiments of coals under graded loading with charge monitoring pre- and post-water drainage from a roof in a coal mine, this study systematically examined the variations of induced charge in …


Evolutionary Characteristics Of Microcracks In Rocks Under Weak Dynamic Disturbance And Disaster Prevention And Control, Jiang Mingwei, Liang Yuntao, Feng Wenbin, Li Haitao, Zhou Rui, Guo Baolong, Liu Yang, Ma Ju Oct 2024

Evolutionary Characteristics Of Microcracks In Rocks Under Weak Dynamic Disturbance And Disaster Prevention And Control, Jiang Mingwei, Liang Yuntao, Feng Wenbin, Li Haitao, Zhou Rui, Guo Baolong, Liu Yang, Ma Ju

Coal Geology & Exploration

Objective High stress with superimposed weak dynamic disturbance serves as a critical factor including rock bursts. However, the microcrack propagation characteristics and energy dissipation pattern of rocks under different disturbance amplitude, frequencies, and unloading ranges remain unclear, leading to a lack of technical support for rock burst prevention and control.Methods Based on the true triaxial unloading dynamic disturbance tests, this study analyzed the instability failure patterns of deep surrounding rocks under different disturbance amplitude (5, 10 MPa), frequencies (4, 10 Hz), and triaxial stress unloading (0, 12 MPa). Moreover, this study examined the characteristics of microcracks in rocks using …


Advances In Research On Stratigraphic Characteristic Parameter Modeling And Safety Early Warning For Deep Geological Drilling Processes, Yang Yulong, Cao Weihua, Gan Chao, Li Yupeng, Wu Min Oct 2024

Advances In Research On Stratigraphic Characteristic Parameter Modeling And Safety Early Warning For Deep Geological Drilling Processes, Yang Yulong, Cao Weihua, Gan Chao, Li Yupeng, Wu Min

Coal Geology & Exploration

Significance As the new round of national exploration & development planning continues, resource exploration is advancing toward the deep Earth. However, deep strata exhibit diverse rock types, which complicate the measurement of rock mechanical parameters. Furthermore, the harsh environments of these strata, characterized by high temperatures, high pressures, and high in-situ stress, are prone to induce downhole accidents like drilling tool failure, wellbore collapse, loss of circulation, and well kicks, posing challenges to geological drilling. Advances Aiming at the perception and modeling of complex geological environments, this study reviews the existing studies on the modeling of stratigraphic characteristic parameters from …


Table Of Contents, The Editors Oct 2024

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Rock Bursts Induced By Thick-Hard Roof With Compound Key Strata: Mechanisms And Technical Modes For Prevention, Zheng Kaige, Yuan Liang, Zhang Pingsong, Wang Lintao Oct 2024

Rock Bursts Induced By Thick-Hard Roof With Compound Key Strata: Mechanisms And Technical Modes For Prevention, Zheng Kaige, Yuan Liang, Zhang Pingsong, Wang Lintao

Coal Geology & Exploration

Objective Thick-hard roofs serve as the key factor inducing disasters such as rock bursts and mining-induced earthquakes in coal mines. These disasters are especially serious in the case of coal seam roofs with compound key strata. Hence, there is an urgent need to reveal the mechanisms behind the rock bursts induced by thick-hard roofs with compound key strata and to develop technical modes for the prevention and control of these rock bursts. Methods Using methods including physical simulation experiments on similar materials and mechanical analysis, this study developed methods for identifying roofs with compound key strata and for non-synergistic breaking …


Mechanisms Behind Mine Earthquake-Induced Dynamic Instability Of Thick Top Coals In High-Stresses Roadways, Zhou Kunyou, Dou Linming, Cao Anye, Ma Yankun, Kan Jiliang, Li Jiazhuo, Ma Xiaotao Oct 2024

Mechanisms Behind Mine Earthquake-Induced Dynamic Instability Of Thick Top Coals In High-Stresses Roadways, Zhou Kunyou, Dou Linming, Cao Anye, Ma Yankun, Kan Jiliang, Li Jiazhuo, Ma Xiaotao

Coal Geology & Exploration

Objective Thick top coals are common in roadways excavated along the bottom of thick coal seams. Mine earthquakes along the mining face can exert dynamic loading on thick top coals in roadways, prone to induce the dynamic instability of thick top coals and even roof fall-rock burst compound disasters. Therefore, there is an urgent need to explore the mechanisms behind the dynamic instability of thick top coals in roadways under dynamic loading induced by mine earthquakes. Methods This study investigated a roadway of deep thick top coals in the Binchang mining area, Shaanxi. Specifically, this study analyzed the dynamic instability …


Mechanism Of Thrust Fault Slip Under The Disturbance Of Stress Waves Induced By Coal Mining, Zhang Ningbo, Xu Qianhai, Ouyang Zhenhua, Li Yizhe, Shi Qingwen, Qin Hongyan, Yi Haiyang Oct 2024

Mechanism Of Thrust Fault Slip Under The Disturbance Of Stress Waves Induced By Coal Mining, Zhang Ningbo, Xu Qianhai, Ouyang Zhenhua, Li Yizhe, Shi Qingwen, Qin Hongyan, Yi Haiyang

Coal Geology & Exploration

Objective The seismic sources, such as roof collapse and artificial blasting, in coal mining may induce stress waves, which will cause the surrounding faults lose its stability and thus cause the dynamic disasters such as rockbursts etc. Methods The propagation law of stress waves in the fracture structure and the evolution characteristics of friction energy under the action of stress waves were studied through dynamic photoelastic experiment, numerical simulation and theoretical analysis based on the thrust fault F16 in Henan Yima mining area. Meanwhile, the disturbance law of the location of seismic source and energy to the slip of thrust …


Fracturing Characteristics Of Significantly Thick Overburden Inducing Mine Earthquakes And The Stress-Triggering Mechanisms Of The Mine Earthquakes, Dou Linming, Cao Anye, Yang Yao, He Hu, Yang Yaoxin, Bai Xianxi, Gu Qianyue, Li Songhui, Fu Xiangchao, Gu Yingshi, Wu Zhen, Zhang Di Oct 2024

Fracturing Characteristics Of Significantly Thick Overburden Inducing Mine Earthquakes And The Stress-Triggering Mechanisms Of The Mine Earthquakes, Dou Linming, Cao Anye, Yang Yao, He Hu, Yang Yaoxin, Bai Xianxi, Gu Qianyue, Li Songhui, Fu Xiangchao, Gu Yingshi, Wu Zhen, Zhang Di

Coal Geology & Exploration

Objective Frequent mine earthquakes that cause surface seismaesthesia, induced by the fracturing of significantly thick overburden in deep coal mining, are identified as the most severe challenge to the efficient production of mining areas. There is an urgent need to overcome the current difficulty caused by mine earthquakes induced by significantly thick overburden, which feature high frequency and challenging prevention and control. Methods Using such mine earthquakes occurring in a certain fully mechanized mining face adjacent to goaves in the Khujirt mining area in Ordos, Inner Mongolia Autonomous Region, as an example, this study (1) analyzed the evolutionary patterns of …


Influencing Analysis Of Bedding Plane Location On The Dynamic Failure Characteristics Of Coal-Rock Combinations, Zheng Jianwei, Zhang Xiufeng, Ju Wenjun, Wang Cunwen, Han Yueyong, Li Guoying, Chen Yang, Li Haitao, Hao Jinwei, Liu Biao Oct 2024

Influencing Analysis Of Bedding Plane Location On The Dynamic Failure Characteristics Of Coal-Rock Combinations, Zheng Jianwei, Zhang Xiufeng, Ju Wenjun, Wang Cunwen, Han Yueyong, Li Guoying, Chen Yang, Li Haitao, Hao Jinwei, Liu Biao

Coal Geology & Exploration

Objective The bedding plane location significantly impacts the dynamic failure processes and mechanical properties of coal-rock composites, but the specific influence patterns remain unclear. Methods Dynamic mechanical tests were conducted on coal-rock composite specimens with bedding planes located at the top, middle, and bottom using the split Hopkinson pressure bar (SHPB). The investigation focused on the dynamic stress-strain behavior, failure process, energy distribution, and fragmentation characteristics under impact loading conditions. Results and Conclusions The findings indicate that: (1) The dynamic stress-strain behavior of coal-rock composites can be segmented into five distinct stages: near-linear stage, nonlinear dynamic stress-strain stage, elastic modulus …


A Dynamic Damage Rate-Based Constitutive Model For Rock Damage, Meng Xiangzhen, Zhang Huimei, Li Yugen, Yuan Chao, Chen Shiguan Oct 2024

A Dynamic Damage Rate-Based Constitutive Model For Rock Damage, Meng Xiangzhen, Zhang Huimei, Li Yugen, Yuan Chao, Chen Shiguan

Coal Geology & Exploration

Objective A constitutive model is identified as the most effective method for describing the deformations and failure characteristics of rocks and characterizing their mechanical behavior. Developing the equation and constitutive model for the dynamic damage evolution of rocks based on changes in their damage rates under loading is an important part of rock mechanics. Methods To further investigate the whole process of rock deformations and failure under loading, rocks were divided into the damaged and undamaged parts via abstraction, with the latter bearing effective stress and the former bearing residual stress. This study established the equation and constitutive model based …


Spatiotemporal Evolutionary Characteristics Of Asymmetric Stress Transfer In Overburden Of Steeply Dipping Coal Seams, Zhu Kaipeng, Li Zhilin, Luo Shenghu, Xie Panshi, Fan Juan, Wang Tong, Tian Chengyang, Yan Zhuangzhuang Oct 2024

Spatiotemporal Evolutionary Characteristics Of Asymmetric Stress Transfer In Overburden Of Steeply Dipping Coal Seams, Zhu Kaipeng, Li Zhilin, Luo Shenghu, Xie Panshi, Fan Juan, Wang Tong, Tian Chengyang, Yan Zhuangzhuang

Coal Geology & Exploration

Objective The key to the safe and efficient mining of steeply dipping coal seams is the effective control of the stability of surrounding rocks, while the effective control is underpinned by identifying and revealing the spatiotemporal evolutionary characteristics of the stress transfer path of the overburden. Methods This study investigated mining face 25221 of a coal mine in Xinjiang through field measurement, physical simulations using similar materials, and numerical computation. This study determined the rock pressure behavior of the mining face, along with the deformation and failure patterns of the overburden, through a comprehensive analysis. Accordingly, it established stress characteristic …


Evolutionary Pattern And Control Technology Of Mine Pressure When Mining Face For Coal Pillars In Main Roadways Passing Through Abandoned Roadways, Li Zhenhua, Ren Ziyuan, Du Feng, Ren Hao, Wang Wenqiang Oct 2024

Evolutionary Pattern And Control Technology Of Mine Pressure When Mining Face For Coal Pillars In Main Roadways Passing Through Abandoned Roadways, Li Zhenhua, Ren Ziyuan, Du Feng, Ren Hao, Wang Wenqiang

Coal Geology & Exploration

Objective With the adjustment of the mining face layout in mines, the overburden roof of the mining face for coal pillar recovery is frequently difficult to control when the mining face passes through abandoned roadways. Methods To address this challenge, this study investigated the coal pillar mining face outside the No.2 panel in the Zhaogu No.2 Coal Mine in Henan Province, which passes through abandoned roadways. Using methods like theoretical analysis, numerical simulation, and in-situ tests, this study examined the composite structure of the mining face and the broken overburden of abandoned roadways, followed by simulation of the full-cycle evolutionary …


Mechanisms And Control Of Rock Bursts In Goaf-Side Roadways Under The Condition Of Thick And Hard Roofs In The Xinjie Mining Area, Inner Mongolia, Liu Wenchao, Zhao Yixin, Guo Jihong Oct 2024

Mechanisms And Control Of Rock Bursts In Goaf-Side Roadways Under The Condition Of Thick And Hard Roofs In The Xinjie Mining Area, Inner Mongolia, Liu Wenchao, Zhao Yixin, Guo Jihong

Coal Geology & Exploration

Objective and Methods Rock bursts in mining roadways in deep coal mines under the condition of thick and hard roofs severely threaten the safe coal mining of the mining face. To meet this threat, this study, focusing on the No.3-1103 mining face auxiliary transport roadway, a goaf-side roadway, in a typical deep mine of the Xinjie mining area, Inner Mongolia, analyzed the external dominant factors and internal driving sources for frequent rock bursts in the goaf-side roadway. Assuming the mechanical characteristics of the rock beam-foundation system, this study constructed mechanical models under loading before roof fracturing based on …


Effect Of Cadmium-Free Filler Metal On Mechanical Properties And Microstructure Of Pdc Cutters, Zhang Suhui, Yao Ningping, Liu Qingxiu, Liu Huan, Wang Dechuan Oct 2024

Effect Of Cadmium-Free Filler Metal On Mechanical Properties And Microstructure Of Pdc Cutters, Zhang Suhui, Yao Ningping, Liu Qingxiu, Liu Huan, Wang Dechuan

Coal Geology & Exploration

Objective PDC bits are critical components of geological support equipment and play a vital role in advancing technology and improving efficiency in the coal industry. Currently, PDC bits are brazed using silver filler metals containing cadmium, a toxic and polluting element. This study introduces the use of environmentally friendly, cadmium-free filler metals for brazing PDC bits. Methods The study investigates the wetting mechanism between brazing filler metals and base materials, utilizing Ag-Cu-Zn series brazing filler metals containing high silver and Sn, Mn and Ni, and only Ni for flame brazing of PDC cutters and steel. The shear strength of different …