Article
Engineering, Geological
Lianpeng Dai, Yishan Pan, Chengguo Zhang, Aiwen Wang, Ismet Canbulat, Tianwei Shi, Chunchen Wei, Ronghuan Cai, Feiyu Liu, Xuepeng Gao
Summary: Risk evaluation of roadway rockburst is important for managing and controlling rockburst during mining operations. By establishing a mechanical analysis model and calculation formulas, a quantitative evaluation method based on critical mining stress index was proposed and validated in a coal mine in Shandong, China.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Thermodynamics
Linjie Hu, Zengchao Feng, Dong Zhou, Xing Wang
Summary: The low permeability and strong adsorption of coal seams make gas drainage difficult. This study focuses on the heat injection method for efficient gas drainage, and its effect and mechanisms were studied through laboratory and field tests. Results showed that heat injection enhanced methane desorption and relieved the inhibitory effect of water on gas, resulting in a significant increase in gas production. Numerical simulation results were consistent with field tests, providing a reference for gas control. Rating: 8/10.
Article
Energy & Fuels
Chao Xu, Haoshi Sun, Kai Wang, Liangliang Qin, Chaofei Guo, Zhijie Wen
Summary: Coalbed methane (CBM) is both a rich clean energy source and a material cause of gas disasters, so gas drainage is necessary for safe mining. Low-level roadway is an effective gas drainage measure that influences stress and permeability properties of coal seams, impacting gas drainage efficiency and air-return roadway layout.
GREENHOUSE GASES-SCIENCE AND TECHNOLOGY
(2021)
Article
Energy & Fuels
Wei Wang, Gang Wang, Wei Zhao, Liang Wang, Zhongkai Feng, Ran Cui, Feng Du
Summary: With the increasing demand for geo-energy, the safe and efficient exploitation of deep coal resources has become increasingly important. A new permeability-enhanced method called hydraulic punching cavitation is proposed to increase the exposed area of coal bulk, release the geo-stress, and improve the coal permeability. The study shows that hydraulic punching cavitation achieves a more extensive plastic zone range and a more notable pressure relief effect than perforation cavitation.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Energy & Fuels
Feng Miao, Di Wu, Xueying Liu, Xiaochun Xiao, Wenbo Zhai, Yanyan Geng
Summary: This study investigated shale gas storage capacity by considering the effect of burial depth on shale pore structure, establishing a model that takes into account the influence of in situ stress. The findings highlight the importance of in situ stress in controlling shale pore structure and gas storage capacity, providing valuable insights for future evaluation of shale gas reserves.
Article
Chemistry, Multidisciplinary
Tatiana Shilova, Sergey Serdyukov
Summary: The study predicted the permeability of gas-bearing coking coals in the Leninsky area of the Kuznetsk coal basin. Laboratory studies showed that as confining pressure increased, coal permeability decreased, and as depth increased, permeability decreased by 61-82%. These findings can be useful for designing industrial works for coal methane extraction in the region.
APPLIED SCIENCES-BASEL
(2021)
Article
Geosciences, Multidisciplinary
Yifei Chen, Yongjian Wang, Fuqiong Huang, Long Ma, Changyi Yang, Haoyu Shi
Summary: In situ stress is a natural phenomenon, where the principal stress ratio of crustal rock mass determines its state (elastic or plastic). Comparing measured data, it is found that the principal stress ratio is dispersed in the shallow part and stable in the deep part. The principal stress ratio can be used to judge the stability of regional strata, with lower ratios indicating better stability and ratios close to the limit indicating instability. Measured data also show that areas with higher principal stress ratios often coincide with recent seismic activity areas, suggesting that in situ stress ratio may be a potential index for earthquake prediction.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Energy & Fuels
Viktor V. Nikitin, Mikhail I. Fokin, Geser A. Dugarov, Arkady N. Drobchik, Vincent De Andrade, Pavel D. Shevchenko, Andrey Yu. Manakov, Anton A. Duchkov
Summary: 3D X-ray imaging provides crucial insights into multi-phase dynamic processes in various geomaterials. Synchrotron phase-contrast tomography techniques achieved necessary contrast levels for dynamic in situ micro-computed tomography of methane-hydrate formation in coal samples, revealing slower formation speed and different growth patterns compared to sand samples. Water extraction from coal grains and competitive sorption of methane were observed, with visualization of this phenomenon through microchannels and nano-tomography imaging for better understanding.
Article
Engineering, Chemical
R. R. Fernandes, N. Suleiman, D. Wilson
Summary: The study used a millimanipulation device as an in situ rheometer to estimate the critical (yield) stress of layers of viscoplastic food and fast-moving consumer goods (FMCG) products on steel plates, showing reasonably good agreement with rotational rheometry results. Particularly, materials with high yield stress yielded more accurate results using the millimanipulation device.
JOURNAL OF FOOD ENGINEERING
(2021)
Article
Geochemistry & Geophysics
Yanan Gao, Yudong Zhang, Zetian Zhang, Minghui Li, Yingfeng Sun, Donghao Lan, Feng Gao
Summary: Gas associated with coal mining is a major hazard that requires gas control to prevent accidents. Drilling and extraction are the main approaches for gas accident prevention. This study investigates the influence of joints on stress and displacement fields around boreholes in jointed coal and rock mass, showing significant effects of joint numbers on maximum displacement.
Article
Energy & Fuels
Fuchao Tian, Zhengdong Liu, Wancheng Zhu, Weiwei Su, Jiaxuan Wang, Jiamei Yang, Zheng Zhang
Summary: This study investigates the dynamic combined effect of coal mass diffusion and seepage on methane migration under different in situ stress conditions. By constructing the physical structure model of coal mass under high and low stresses and obtaining the diffusion parameters of coal mass, the methane migration in coal mass was calculated using a coupled multifield model. The results demonstrate that the extraction difficulty of methane is directly proportional to stress, and there is a significant discrepancy in methane migration under high and low stresses. A joint technical method for promoting methane flow rate under multicoal seam conditions is proposed based on the controlling factors in methane migration.
Article
Energy & Fuels
Zhengdong Liu, Xiaosong Lin, Zhenyang Wang, Zheng Zhang, Rui Chen, Liang Wang, Wei Li
Summary: Gas desorption and diffusion in coal seams under high stress conditions were investigated in this study. Experimental tests were conducted on coal samples under different high stress conditions, and the desorption laws and permeability evolution laws were obtained. A diffusion model for coal under high stress was established based on reasonable assumptions and the relationship between diffusion length and stress. The research results provided comprehensive theoretical support for the application of pressure relief mining technology in deep high-stress coal seams.
Article
Engineering, Civil
Jianli Shao, Qi Zhang, Wenquan Zhang, Zaiyong Wang, Xintao Wu
Summary: Pre-drainage of groundwater in the roof aquifer by boreholes is an effective method for preventing roof water disasters, but it can also lead to local stress variations. The study found that as the water level drops during drainage, different stress zones form around the borehole, which can increase the risk of stress concentration in the overlying strata.
GEOMECHANICS AND ENGINEERING
(2021)
Article
Geochemistry & Geophysics
Kun Zhang, Fengfeng Wu, Xin Yue
Summary: By combining theoretical analysis and practical research on large coal pillars in deep mines, this study determined a reasonable width for the coal pillars and successfully applied it in engineering projects, achieving satisfactory results.
Article
Chemistry, Multidisciplinary
Ali Reza Torabi, Kazem Hamidi, Abdol Saleh Rahimi, Sergio Cicero
Summary: This study investigates the fracture behavior of notched polymeric specimens under compressive stresses through experimental and theoretical methods. The use of the Equivalent Material Concept (EMC) in combination with the Maximum Tangential Stress (MTS) and Mean Stress (MS) criteria accurately predicts the load-carrying capacity of the specimens without the need for experimental calibration.
APPLIED SCIENCES-BASEL
(2021)