Article
Energy & Fuels
Haosen Wang, Jiong Wang, Manchao He, Zimin Ma, Xichun Tian, Peng Liu
Summary: In longwall top coal caving (LTCC) mining methods, a novel non-pillar coal mining technology was used to address problems related to increased production in single mining panels. This technology involved cutting off stress transmission, eliminating coal pillars, and retaining the gob-side entry. The technology utilized four techniques, including constant resistance and large deformation anchor cable, directional roof split blasting, blocking-gangue support system (BGSS), and temporary support system. Field monitoring results showed that the technology effectively stabilized the surrounding rock and controlled deformation of the retained entry.
ENERGY SCIENCE & ENGINEERING
(2023)
Article
Environmental Sciences
Yafei Yuan, Meinan Zheng, Huaizhan Li, Yu Chen, Guangli Guo, Zhe Su, Wenqi Huo
Summary: The present study proposes a three-dimensional deformation monitoring method that combines mining subsidence law with SAR imaging to better delineate the surface subsidence range in coal mining. By comparing with ground leveling measurements, the results show that the proposed method achieves higher monitoring accuracy in determining the mining impact area.
Article
Mining & Mineral Processing
Lukasz Wojtecki, Joanna Kurzeja, Malgorzata Knopik
Summary: This article attempted to determine the influence of mining factors on seismic activity during longwall mining in a Polish coal mine. Various tools of mining seismology were used to illustrate this influence, and a new solution based on the slope of a fitted line in a moving time window was proposed.
INTERNATIONAL JOURNAL OF MINING SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Mechanical
Maolin Tian, Lijun Han, Hongtian Xiao, Qingbin Meng
Summary: This paper presents results of physical model experiments studying the deformation and failure process of coal seam in front of a longwall working face, introducing the concept of integrity coefficient to evaluate coal seam failures. Results show that coal seam undergoes a complex fracturing process during face advancement, with fracture types being related to distance from the working face wall.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Geochemistry & Geophysics
Penghua Han, Cun Zhang, Zhaopeng Ren, Xiang He, Sheng Jia
Summary: As the advance speed of the longwall face increases, the first (periodic) rupture interval of the main roof and key stratum increases, while roof subsidence, fracture angle, and rotation angle decrease. Additionally, with increasing advance speed, the range of roof displacement gradually decreases, and the impact range of the advance speed on roof subsidence is 75 meters behind the longwall face. Increasing the advance speed of the longwall face results in a 3.28% increase in impact load from sliding instability of fractured rock in the main roof, while causing a 5.79% decrease in additional load from roof rotation, ultimately leading to a 9.63% increase in the average dynamic load coefficient of support.
JOURNAL OF GEOPHYSICS AND ENGINEERING
(2021)
Review
Engineering, Environmental
JiaChen Wang, Meng Li, ZhaoHui Wang, YueSong Tang, JiaLong Li, Zheng Li, ZhiFeng Wang
Summary: A support stiffness based method is proposed to improve the stability of coal wall in a panel retraction period in Zhaogu coalfield. The study reveals that the support stiffness ranges from 50 to 450 MN/m and varies in three zones along the face length direction. Fracture development of the coal wall is high in the middle section and decreases from middle to side areas. Based on these findings, a mechanical model is established, which shows a negative relationship between roof pressure and support stiffness. Numerical modeling validates the importance of support stiffness in face stability.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2023)
Article
Multidisciplinary Sciences
A. K. M. Badrul Alam, Yoshiaki Fujii, Shaolin Jahan Eidee, Sophea Boeut, Afikah Binti Rahim
Summary: Accurately predicting mining-induced subsidence is essential for sustainable mine management. The subsidence caused by the mining of Northern Upper Panels (NUP) and Southern Lower Panels (SLP) at the Barapukuria longwall coal mine was simulated using the Displacement Discontinuity Method. The effects of various factors, such as the ground surface, mining panels, faults, and the dyke, were considered in the numerical model. The predicted subsidence was compared with the observed subsidence, and the best match in terms of Young's modulus was determined. Future subsidence was also predicted, and vulnerable areas were identified based on tilt angle and extensile strain.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Mechanical
Haosen Wang, Jiong Wang, Davide Elmo, Manchao He, Zimin Ma, Chengzhang Gao
Summary: This paper presents an integrated approach for theoretical analysis and numerical modeling to investigate the ground response mechanism of entries and control methods induced by hard roof in longwall top coal caving panel (LTCC). A roof mechanical model for the main roof's different breaking positions was created to study the ground response mechanism of gob-side entries. The results of the theoretical analysis and numerical simulation suggest that the directional roof split blasting technique for pressure relief and automatic retained entry (DRSBPRRE) approach is a safe and efficient mining method for pressure relief and entry retention.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Xiaozhen Wang, Jianlin Xie, Jialin Xu, Weibing Zhu, Limin Wang
Summary: The study explored the influence of mining height and width on overburden subsidence in longwall pier-column backfilling. Numerical simulations and physical similarity models were used to analyze the control effect of overburden subsidence, providing strong theoretical support for evaluating the control effect in this backfilling method.
APPLIED SCIENCES-BASEL
(2021)
Article
Green & Sustainable Science & Technology
Qi Ma, Yidong Zhang, Yu Zheng, Zexin Li, Guangyuan Song, Lei Hu
Summary: This study focuses on the serious coal compression issues under buildings, railways, and water bodies in central and eastern China, as well as the wide range of rock formation damage, high mine pressure, and difficulties in controlling surface subsidence after mining. Through laboratory tests and numerical simulations, the mechanical properties of gangue paste-filling materials, the fracturing process of the coal seam roof, overlying stratum movement, and mine pressure weakening law were studied. The findings provide a scientific basis for green backfill mining, roadway support design, and backfill mining equipment selection.
Article
Chemistry, Multidisciplinary
Zi-Lu Liu, Zhan-Guo Ma, Oleg Ivanovich Kazanin, Peng Gong, Ye Li, Xiao-Yan Ni
Summary: Taking into account the factors affecting gob-side entry retaining, this study discusses the suitability of using large-diameter, concrete-filled steel tube as a roadside support body in top-coal caving fully mechanized faces. A new approach to gob-side entry retaining is proposed based on the mechanical model of the surrounding rock structure and numerical simulation analysis. The study highlights the significance of column spacing and the contact interface between the concrete-filled steel tubes and the roof in controlling the deformation of the retained roadway.
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Multidisciplinary
Rong Zhang, Congmeng Hao
Summary: This paper discusses the key technology of stress unloading and permeability enhancement in soft and low permeability tectonic coal seams (SLPTCSs) in China, which is caverning by hydraulic flushing. The study also examines the development of hydraulic flushing caverning technology and equipment in China. Field tests conducted in two coal mines show that highly integrated equipment for caverning by hydraulic flushing can efficiently enlarge caverns, improve coal seam permeability, and increase gas extraction efficiency. This technology provides valuable guidance for gas control in SLPTCSs.
Article
Acoustics
Shenghu Luo, Tong Wang, Yongping Wu, Jingyu Huangfu
Summary: This study analyzes the difficulties in controlling the stability of the support during longwall mining of steeply dipping coal seams and the characteristics of the nonuniform filled-in gob. The findings provide important reference and guidance for longwall mining applications.
SHOCK AND VIBRATION
(2022)
Article
Engineering, Geological
Jianlin Xie, Qingdong Qu, Weibing Zhu, Xiaozhen Wang, Jialin Xu, Shan Ning, Tao Hou, Xun Luo
Summary: This paper presents an in-situ monitoring study of overburden strain dynamics at a kilometre-deep longwall mine using distributed fibre optic sensing technology. The study found that the dynamic deformation of overburden is primarily governed by competent stratum units, and the monitoring results are helpful in preventing dynamic hazards. The study also demonstrates the potential of DFOS-based strain monitoring in various mining methods.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Engineering, Environmental
Dong Ma, Botao Qin, Yuan Gao, Jianan Jiang, Baochao Feng
Summary: This study focused on investigating methane migration induced by coal spontaneous combustion using a self-designed experimental platform, analyzing the effects of temperature and range of spontaneous combustion on methane distribution, and quantitatively identifying potential areas subject to methane explosions.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2021)
