Engineering Commons^™

Advancing Coal Rib Support Design Through The Integration Of Field Studies And Numerical Simulations, Alper Kirmaci

Doctoral Dissertations

Coal rib stability remains a major safety concern in U.S. underground coal mines, with rib failure-related injuries and fatalities still occurring. A key challenge is the lack of a standardized methodology for designing rib support systems that can address varying geological conditions. As a result, many mines rely on trial-and-error or traditional practices, leading to inconsistent designs. This research aims to develop a systematic methodology for rib support design to improve coal rib stability in U.S. mining operations.

The study consists of: i) field monitoring in active room-and-pillar coal mines, ii) in-situ pull-out tests on coal ribs, iii) numerical model …

Analysis Of Pull-Out Tests For Resin-Grouted Rib Bolts, Khaled Mohamed, Yuting Xue, Dogukan Guner, Alper Kirmaci, Taghi Sherizadeh

Mining Engineering Faculty Research & Creative Works

Resin-grouted rib bolts serve as a crucial means of stabilizing spalling of coal ribs in underground coal mines. A comprehensive investigation into their efficacy was undertaken by a collaborative effort between the National Institute for Occupational Safety and Health (NIOSH) and Missouri University of Science and Technology (MST). This study involved pull-out tests of rib bolts in multiple locations, including six coal mines and the NIOSH research mine. A total of seventy-three (73) pull-out tests were conducted for rib bolts installed at different rotation speeds and a wide range of anchorage lengths, ranging from a short encapsulation length of 0.305 …

Sustmine: A Framework For Integrating Sustainable Development Dimensions Into Strategic Mine Planning, Hussam Altalhi, Kwame Awuah-Offei, Gabriel Nicolosi, Abdullah Al Moinee, Nasib Al Habib

Mining Engineering Faculty Research & Creative Works

Strategic mine planning involves optimizing resource extraction to achieve economic, environmental, and social objectives. However, only a few frameworks offer a unified approach that simultaneously employs systematic indicator selection and weightless trade-off evaluation. This study addresses these issues by proposing a comprehensive framework for integrating sustainability into strategic mine planning, named SustMine. SustMine introduces two key advancements: (1) a rigorous, systematic, criteria-based process for selecting site-specific sustainable development indicators (SDIs), and (2) a weightless evaluation strategy that utilizes Pareto front analysis to construct composite indices. This allows decision-makers to identify non-dominated (optimally balanced) alternatives without relying on arbitrary or subjective …

Investigating Surface-Borehole Transient Electromagnetic Responses From Veined Orebodies Considering Induced Polarization Effects, Li Jianhui, Wang Yao, Wang Wenchuang, Xie Shaojian, Zhu Siwei

Coal Geology & Exploration

Objective The observational data derived using the surface-borehole transient electromagnetic (TEM) method tend to feature complex curve morphologies, a problem posing significant challenges to data processing and interpretation. This study aims to ascertain the mechanisms behind the generation of such complex responses using forward modeling.Methods Using the vector finite element-based spectral method and the Cole-Cole model, this study developed a 3D forward modeling technique incorporating the induced polarization (IP) effect. By constructing a typical theoretical model of low-resistivity veined orebodies, it systematically analyzed the electromotive force (EMF) responses excited by transmitter loops at different orientations. Results and Conclusions The …

Coal Body Structure Identification Method Based On Bayesian-Optimized Cnn-Bilstm-Attention, Bian Huiyuan, Ji Jiajun, Duan Chaowei, Zhou Jun, Li Kun, Ma Yuhan

Coal Geology & Exploration

Background Coal-bearing basins contain primary and tectonically deformed coals due to multistage tectonic deformations. However, the gas-bearing properties of coal seams differ significantly due to varying pore and fracture densities, permeability, and mechanical properties. This makes coal structure assessment critical to coalbed methane (CBM) exploration and production. Objective and Method To enhance the accuracy and intelligence of coal structure identification, this study constructed a CNN-BiLSTM-Attention hybrid model that integrated a Bayesian optimization strategy. This model allowed for efficient fusion and representation of multi-scale log data by combining the local feature extraction capability of the convolutional neural network (CNN), the temporal …

Self-Adaptive Inverse Wavefield Transform And Derived Pseudo-Wavefield Characteristics Under Roadway-Borehole Observation Of Transient Electromagnetic Data, Fan Kerui, Guo Jianlei, Wang Ruoyu, Zhuang Ming, Fan Fangze, Xu Sheng, Zhao Wentao

Coal Geology & Exploration

Objective To address the challenge of detecting aquifers outside the roadway excavation contour, this study combined the close-range detection via roadway-borehole transient electromagnetic (TEM) method with the wavefield transform. This will help simultaneously receive detection signals in front of the mining face and outside the roadway excavation contour while also highlighting the boundary information of aquifers. Moreover, to obtain a pseudo-wavefield featuring both reasonable kinematic characteristics and high sensitivity to changes in the electrical structures of strata, this study proposed a self-adaptive algorithm of inverse wavefield transform, thereby improving the accuracy and efficiency of the inverse wavefield transform of roadway-borehole …

Performance And Migration Path Tracing Of Magnetic Grouts For Fractured Rock Masses, Shang Hongbo, Wang Hao, Wang Xiaodong, Qiao Wei, Wang Tiantian, Sun Junqing, Sun Jie

Coal Geology & Exploration

Objective For coal mining areas in the middle reaches of the Yellow River basin, sealing mining-induced fractures via grouting serves as an effective approach to preventing water inrushes from coal seam roofs while also protecting groundwater resources. However, accurately identifying the migration paths of grouts remains a bottleneck for the further application of grouting modification technology to fractured rock masses. Methods This study investigated a coal mine threatened by both water inrushes from the coal seam roof and a short supply of water resources within the Jurassic coalfield in the middle reaches of the Yellow River basin, focusing on the …

An Automated Attitude Control Method For The Rotary Steerable System And Its Validation Through Hardware-In-The-Loop Simulation, Zhang Nan, Ren Bai’An, Li Fei, Liu Ziqi, Lyu Fangxing

Coal Geology & Exploration

Objective The traditional manual control mode of a rotary steerable system (RSS) faces challenges, including response delay and low control efficiency. To address these challenges, this study proposed a closed-loop automated attitude control method for the RSS and verified its effectiveness through hardware-in-loop (HIL) simulation. Methods This study focuses on the drilling process of a point-the-bit RSS. In the case of deviations between measured and target attitudes, the control parameters were calculated based on the deviation signals using a closed-loop controller, driving the RSS actuator to conduct trajectory correction. Afterward, the actual attitude was yielded and then entered the input …

Co2-Water Displacement Characteristics Of Saturated Sandstones With Different Pore Structures, Liu Ting, Li Jinglin, Li Yi, Dan Wendong, Diao Yujie, Ma Xin

Coal Geology & Exploration

Objective The pore structures of clastics play a crucial role in assessing the potential of saline aquifers for geologic CO₂ sequestration. Current studies on pore structures during CO₂ sequestration focus primarily on artificial cores. However, compared to artificial cores, natural cores feature more complex pore size distributions and stronger heterogeneity. Methods This study examined a natural core from deep reservoirs in the Ordos Basin and two artificial cores with different porosities through CO₂-water displacement experiments under water-saturated conditions. Using a nuclear magnetic resonance (NMR) analysis and imaging system for multiphase fluid displacement, this study analyzed the …

Impacts Of Anti-Rock Burst Multistage Hydraulic Fracturing Using Horizontal Wells On Mining Roadways And Fracture Control Techniques: A Case Study Of Mining Facein The Zhaoxian Coal Mine, Shaanxi Province, Liu Xiugang, Jiang Zaibing, Yang Juan, Liu Mingjun, Pang Tao, Wu Weixing, Tu Xiaolong, Mo Haitao, Guo Xiaolong, Du Xinfeng

Coal Geology & Exploration

Objective Surface multistage hydraulic fracturing of hard roofs using horizontal wells serves as an important technique for rock burst control in mines. However, fracturing technique under improper control might pose adverse impacts on excavated mining roadways underground, causing roadway deformation, mesh failure with block falling, and the flow of fracturing fluids into the roadways. Methods This study investigated certain mining face of the Zhaoxian Coal Mine in the Yonglong mining area, Shaanxi Province. Targeting different characteristics and phenomena of roadways following hydraulic fracturing, this study analyzed the reasons why fracturing fluids flowed into roadways during hydraulic fracturing using theoretical analysis, …

Lithofacies Paleogeography Of The Ordovician Kelimoli-Lashizhong Formations Along The Western Margin Of The Ordos Basin, Wang Weibin, Ma Zhanrong, Hu Aiping, Zhang Qian, Li Wenhou, Chen Qiang, Ma Yao, Wang Yanbo

Coal Geology & Exploration

Objective The period during the deposition of the Middle-Late Ordovician Kelimoli-Lashizhong formations witnessed a key transition of the tectonic framework along the western margin of the Ordos Basin. Investigating the lithofacies paleogeography of these formations can reveal the tectono-sedimentary responses during this period, thereby providing a basis for the resource potential prediction, exploration, and exploitation of natural gas in the study area. Methods Using field section observations, core observations, and log interpretations, as well as previous research results, this study comprehensively analyzed the Middle-Late Ordovician strata in the Ordos Basin from the perspectives of stratigraphy, sedimentary system division, and sedimentary …

Intelligent Lithology Identification While Drilling Using Bilstm Integrating Attention Mechanism, Wang Xi, Peng Fengjia, Li Siyang, Guo Xiao, Zhang Feifei, Ran Xiaofeng, Zhang Cong

Coal Geology & Exploration

Objective Vibration signals while drilling reflect the physical properties and microstructural characteristics of rocks, providing a valuable basis for real-time lithology identification. However, existing models suffer from limited accuracy and robustness due to the low dimensionality of signal features and the class imbalance induced by variations in the rock layer thickness. Methods To overcome these limitations, this study proposed a novel lithology identification method based on a bidirectional long short-term memory (BiLSTM) network that integrates attention mechanism (also referred to as the BiLSTM-Attention). This approach incorporates automated feature extraction and class weight adjustment strategies to enhance both the classification performance …

Uniqueness And Prospects Of Co2 Sequestration In Basalts, Hu Chenlin, Sang Shuxun, Li Xin, Rui Zhenhua, Liu Shiqi, Wang Ziqiang, Xie An, Yu Huan

Coal Geology & Exploration

Objective and Method CO₂ sequestration in basalts offers advantages such as permanent carbonation and elevated safety. Based on literature review and case studies, this study compared the CO₂ sequestration performance of basalts, clastic rocks, and carbonate rocks. Accordingly, the pros and cons of technologies for CO₂ sequestration in these rocks were determined, and the dominant mechanisms underlying the CO₂ sequestration were identified. By revealing the characteristics of CO₂ sequestration in the three rock types based on representative projects and tests, this study conducted a comparative analysis of the mechanisms, conditions, technologies, potential, and siting for …

A Simulation Study On A Dual-Borehole Dc Resistivity System For Advance Detection Under Varying Angles, Zhou Guanqun, Xu Shaotian, Zhang Weixin, Wang Yafei, Wu Xiaoping, Hu Xiongwu, Chen Xinghai, Cao Yu

Coal Geology & Exploration

Significance Mine direct current (DC) methods, an efficient geophysical exploration technique, can be used to identify and delineate underground electrical resistivity anomalies, serving as a critical means for the advance detection of water-bearing or hydraulically conductive structures ahead of the mining face. Methods By combining the water exploration and discharge boreholes commonly used in coal mining and making reference to the observation system of the ground-based cross-borehole DC resistivity CT method, this study devised a dual-borehole DC resistivity observation system for advance detection. Through numerical simulation using the COMSOL software, this study constructed a homogeneous full-space model, in which a …

Structural Evolution And Spontaneous Combustion And Activation Mechanisms Of Coals Treated Under Inert Atmospheres In A Coal Mine Goaf, Zhang Leilin, Li Wanting, Wen Chenchen

Coal Geology & Exploration

Objective When used for the treatment of fire zones in deep coal mine goafs, low-oxygen and inertization techniques suffer from a scientifically blind spot, i.e., the fire prevention and control bottleneck caused by a high susceptibility to re-ignition of coals after being treated with high-temperature, low-oxygen (or inert) gas. To overcome this limitation, this study aims to systematically determine the mechanisms by which the evolution of the physical and chemical structures of coals after heat treatment under different atmospheres influences their spontaneous combustion and activation behavior. The purpose is to provide theoretical support for the treatment and safe opening of …

A Method For Interpretating Acoustic Reflection Imaging Logging Data Of Fractured-Vuggy Reservoirs Based On Their Theoretical Response Characteristics, Huang Ruokun, Jiang Kai, Wu Xingneng, Ma Kunyu, Su Yuanda, Wang Bing, Chen Xu

Coal Geology & Exploration

Objective During the exploration and development of fractured-vuggy carbonate reservoirs, acoustic reflection imaging logging technology enables the detection of fractured-vuggy bodies around wells. However, this technology suffers from unclear response characteristics and a strong multiplicity of solutions. Focusing on the Tarim Oilfield, this study aims to establish a tailored interpretation method by integrating geological and geophysical characteristics. The purpose is to enhance the identification accuracy and reliability of fractured-vuggy bodies in these reservoirs. Methods Based on the distribution characteristics of fractured-vuggy carbonate reservoirs in the Tarim Oilfield, this study established the numerical simulation models of three typical fractured-vuggy bodies: inter-breccia …

Numerical Simulations Of Dynamic Rock Damage Under Laser-Induced Shock Waves, Xu Yuelin, Qin Enwei, Li Wei, Wang Ying

Coal Geology & Exploration

Objective Traditional laser thermal rock breaking technologies suffer from high energy consumption and a limited damage depth. To overcome these challenges, this study proposed a novel mechanical rock breaking method based on high-pressure plasma shock waves induced by short pulsed lasers, aiming to transform a thermodynamics-dominated rock breaking mechanism into a dynamics-dominated mechanism. Methods and Results Under the Abaqus/Explicit explicit dynamics framework, this study constructed a finite element model to simulate the interactions between nanosecond laser-induced shock waves and rocks. The accurate loading of shock wave pressure in the spatial and temporal domains was achieved using the VDLOAD user subroutine. …

A Novel Model For Calculating In Situ Stress Within Deep Coal Seams Considering Microstructural Characteristics And Its Application, Zhao Haifeng, Shi Hongwei, Xie Fei, Wang Chengwang, Wang Zongfei, Chen Gaojie

Coal Geology & Exploration

Objective Research on in situ stress serves as a bridge between geological and engineering analyses. Accurate insights into in situ stress regimes are crucial for ensuring engineering efficiency and development benefits. However, microstructures are well developed in deep coal seams, for which no effective model is currently available for calculating in situ stress. Methods and Results By classifying structures into macrostructures and microstructures, this study established a novel model for calculating in situ stress in deep coal seams while considering microstructural characteristics. In the novel model, the horizontal in situ stress was decomposed into three components: the horizontal components induced …

Technique For Water-Preserved Coal Mining Based On Zonal Height Limits Along Mining Face And Mechanisms Behind Overburden Failure, Sun Xueyang, Cao Hongyi, Li Peng, Han Dehao, Luo Qiyao, Liu Kuan, Li Jihong, Yin Xu

Coal Geology & Exploration

Objective The exploitation of shallow coal seams under water bodies faces a contradiction between water resource preservation and overburden disturbance. In this case, achieving safe mining while preventing water-conducting fracture zones from affecting key aquifers and exploring techniques that place equal emphasis on water preservation and efficient resource recovery have emerged as popular research topics. Methods An integrated aquifer-overburden-coal seam model was constructed using 3D geological visualization technology. This model, combined with the principles for the setting up of waterproof coal pillars, enabled accurate delineation of zones with water inrush risks. Accordingly, a technical scheme for mining based on zonal …

Simulation Of Groundwater Flow Field Evolution And Water Inrush Risks Under The Deep-Well Reinjection Of High-Tds Mine Water, Liu Qi, Sun Yajun, Fan Jianguo, Tan Xianfeng, Xiao Shengxin, Yang Chuanwei, Chen Weiyang, Chen Ge

Coal Geology & Exploration

Objective The deep-well reinjection of mine water results in a regional groundwater level rise to varying degrees, possibly inducing hydrogeological hazards such as floor water inrushes or water inrushes along faults. In this context, determining the evolutionary pattern of the groundwater flow field under long-term mine water reinjection and conducting reinjection safety assessments play a critical role in ensuring both the safety of mine water reinjection and water conservation-based coal mining.Methods This study examined the reinjection of mine water in a coal mine within the Juye coalfield, North China. Based on the geological conditions for mine water reinjection in …

An Experimental Study On The Deterioration Characteristics Of Sandstone Masses With Rock Bridges Under Cyclic Freezing And Thawing, Zhang Huimei, Li Zengle, Chen Shiguan, Yuan Chao, Zheng Shihang

Coal Geology & Exploration

Objective To determine the deformation and failure mechanisms of fractured rock masses with rock bridges in alpine regions, this study conducted mechanical property tests on rock samples with varying lengths of rock bridges subjected to cyclic freezing and thawing. Methods Through experiments, this study summarized the characteristics of the static strength deterioration of rock masses under the combined effects of different numbers of freezing and thawing cycles and varying rock bridge lengths. By combining acoustic emission signal monitoring and scanning electron microscopy, this study thoroughly explored both the evolutionary characteristics of fractures and rock rupture modes. Accordingly, it revealed the …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Reservoir Responses To Reactions In Co2 Mineral Trapping And Geologic Carbon Sequestration Prospects For Basalts In Western Guizhou Province, China, Han Sijie, Ai Zhixi, Liu Jijie, Zhou Xiaozhi, Gao Wei, Liu Zhu

Coal Geology & Exploration

Background Geologic CO₂ sequestration in basalts has attracted wide attention in recent years owing to its safe, stable, and efficient CO₂ trapping mechanisms.Methods Focusing on basalts in the Longtan Formation within western Guizhou Province, China, this study simulated the CO₂-water-basalt geochemical reactions under varying temperatures, pressures, and times. Through tests and comparison of mineralogy, geochemistry, and reservoir physical properties before and after the reactions, this study investigated the factors influencing the reactions and elucidated the post-reaction co-evolution mechanism between minerals and pores. Furthermore, the mechanisms behind CO₂ trapping in basalts were summarized, and the …

Spatial Distribution And Source-Sink Matching Of Stationary Co2 Emissions In Zhejiang Province, Zhu Qianlin, Chen Dongbao, Liu Hanxiao, Lu Shijian, Chen Fu

Coal Geology & Exploration

Objective Carbon capture, utilization, and storage (CCUS) is supposed to become an essential technology for the consumption of fossil fuels under the background of achieving carbon neutrality. Delving into the spatial distribution of regional CO₂ stationary sources and the source-sink matching characteristics will contribute to more rational decision-making in CCUS deployment and promote the development of carbon sequestration technology. Methods This study investigated the spatial distribution of CO₂ stationary sources in Zhejiang Province and, using the carbon emission factor method, assessed their CO₂ emissions based on their scales. Furthermore, it analyzed the geological features of both onshore …

Supersaturation Effect And Its Characterization In Gas-Rich Intervals Of Deep Coal Seams, Zhou Lihong, Li Yong, Ding Rong, Li Yun, Li Yongzhou, Kong Jintao

Coal Geology & Exploration

Objective and Method High free gas content serves as a key factor controlling the enrichment and high productivity of deep coalbed methane (CBM). However, its direct determination is challenging, making the accurate identification of free gas-rich coal seam intervals a core scientific issue for efficient exploration and recovery of CBM. This study investigated the Daning-Jixian block (also referred to as the Daji Block) within the Ordos Basin. Based on analyses and tests of the gas content, coal macrolithotype, physical properties, and log responses of cores collected from representative wells through pressure-retained coring, this study systematically assessed the vertical heterogeneity of …

Physical Simulation Experiments On 4d Visualization Of Dynamic Methane Diffusion And Adsorption In Low-Porosity And Low-Permeability Coals, Liu Tong, Jiao Baizhuo, Lin Baiquan, Sang Shuxun, Yang Wei, Liu Shiqi, Liu Ting, Li He, Yang Mingxing

Coal Geology & Exploration

Objective and Method The diffusivity of methane (CH₄) in coal seams significantly influences the surface extraction of coalbed methane (CBM) and underground gas drainage. However, the visualized characterization of the diffusion and migration processes of CH₄ in coals remains challenging. To address this issue, this study systematically demonstrated the similarity between krypton (Kr) and CH₄ in their adsorption and diffusion behavior in coals. Utilizing Kr—a gas with high X-ray attenuation—as a tracer substitute for CH₄, this study achieved the transparent observation of the dynamic gas migration process in low-porosity, low-permeability, and heterogeneous coals using …

Organically-Bound Forms Of Alkali And Alkaline Earth Metals In High-Alkali Coals And Their Geological Indications, Wang Xiaoling, Wang Shaoqing, Zhao Yungang, Mu Ruifeng, Shao Yan

Coal Geology & Exploration

Objective and Method Alkali and alkaline earth metals (AAEMs) in coals adversely affect coal processing and utilization. Among the AAEMs, water-soluble and mineral-hosted metals can be largely removed through water washing, flotation, and heavy liquid separation, while organically-bound AAEMs are difficult to eliminate. In this study, high-alkali coal samples with varying vitrinite/inertinite ratios (V/Is) collected from the Zhundong coalfield in Xinjiang were selected to investigate the organically-bound forms of AAEMs. Through sequential chemical extraction, combined with experimental techniques such as ²³Na cross-polarization magic-angle spinning nuclear magnetic resonance (²³Na CP/MAS NMR) and transmission electron microscopy-energy dispersive …

Mechanisms Behind Soil Water Evaporation And Infiltration During Long-Term Microbial Reclamation In Coal Mining-Induced Subsidence Areas In Northern Shaanxi Province, China, Ke Zengming, Bi Yinli, Yang Wei

Coal Geology & Exploration

Background Water scarcity is identified as an important factor restricting ecological restoration in arid and semi-arid mining areas. The application of microbial reclamation technologies, especially inoculation with Arbuscular mycorrhizal fungi (AMF), has achieved encouraging ecological effects in mining areas. In this case, investigating soil water movement and its controlling factors in mining areas undergoing long-term microbial reclamation is a key scientific issue for understanding the long-term ecological restoration mechanisms of AMF. Methods This study investigated the microbial reclamation base in the coal mining-induced subsidence area of the Daliuta coal mine of northern Shaanxi Province, located in the middle reaches of …

An Experimental Study On The Selection Of Slow-Release Carbon Source Materials For Sulfate-Reducing Bacteria-Based Remediation Of High-Sulfate Mine Water In Coal Mines, Xiahou Ming’An, Zhang Li, Xu Zhimin, Guo Juan, Chen Ge, Xiong Xiaofeng, Sun Yajun

Coal Geology & Exploration

Background High-sulfate mine water poses a major aquatic environmental challenge in coal mining areas across China. Accordingly, the cost-effective and efficient treatment of such water has become an urgent need for the sustainable development of the mining industry. Despite its considerable promise, microbial remediation based on sulfate-reducing bacteria (SRB) shows limited efficiency due to the scarcity of dissolved organic carbon (DOC) in mine water.Methods The application of external slow-release carbon source (SRC) materials for SRB faces a range of challenges, such as the potentially excessive release of organic carbon in the initial stage, the unclear release mechanisms of dissolved …

Failure Mechanisms And Energy Dissipation Characteristics Of Anchorage Bodies Under Dynamic Loading, Wang Changcheng, Yang Ke, Liu Wenjie, Zhang Zhainan, Zheng Shizhang, Xu Rijie, Guo Penghui

Coal Geology & Exploration

Objective Under intense mining in deep parts of coal mines, the roadway support systems are significantly affected by both far- and near-field dynamic loads, accompanied by the strong deformations of the surrounding rocks. Therefore, investigating the failure mechanisms of anchorage bodies under dynamic loading becomes particularly important. Methods Using the split Hopkinson pressure bar (SHPB) test system and digital image correlation (DIC) technology, the study investigated the mechanical response characteristics of the anchorage bodies under different impact air pressures. Accordingly, it determined dynamic stress-strain relationships, energy dissipation characteristics, cracks’ evolutionary patterns, and failure modes of anchorage bodies. Results and Conclusions …