Article
Mechanics
Yushun Yang, Dongming Zhang, Yun Dong, Jihua Zhang, Xiaoming Li, Chunlei Zhang, Jingke Wu
Summary: The study found that the volumetric strain gradually increases and permeability exponentially decreases with the increase in effective stress during loading axial stress. In the process of simultaneous unloading axial stress and loading confining pressure, the volumetric strain of coal sample increases while the permeability decreases exponentially with the increase in effective stress.
Article
Engineering, Geological
Long Yan, Weiya Xu, Rubin Wang, Huanling Wang, Wei-Chau Xie
Summary: This paper presents an experimental study on the mechanical behavior and permeability evolution of basalt under hydro-mechanical coupling conditions. The relationship between confining pressure and steady creep rate was described by an exponential function, while the evolution of permeability exhibited phased characteristics. These results provide insights for the long-term stability assessment of basalt under coupled hydro-mechanical conditions.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Engineering, Chemical
Haibo Sun, Baoyong Zhang, Zhijun Song, Bin Shen, Hongyu Song
Summary: This study conducted mechanics-seepage synchronous tests and numerical simulations to analyze the effects of load path on the mechanical strength and permeability of coal disturbed by deep mining. The results provide insights for research and disaster prevention regarding coal and gas outburst.
Article
Energy & Fuels
Quanqi Zhu, Diyuan Li, Wenjian Wang
Summary: Permeability, a fundamental index related to rock damage, was studied through dynamic triaxial compression tests on sandstone under various conditions. Results showed that peak stress, strain, plasticity, damage, and permeability increase with higher incident energy. Only peak stress increases with higher confining pressure.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2021)
Article
Chemistry, Multidisciplinary
Zhiqi Wang, Xufei Gong, Xuebin Gu
Summary: By conducting triaxial compression tests on fractured coal specimens, the research investigates the mechanical properties, failure characteristics, fractal characteristics, and energy evolution law of shallow fractured coal in the Western China mining area. The results reveal the changes in stress-strain curve, mechanical properties, failure mode, and energy evolution with the increase of prefabricated crack number. The findings contribute to a better understanding of the failure mechanism of fractured coal and its application in control design.
APPLIED SCIENCES-BASEL
(2022)
Article
Energy & Fuels
Xin Bai, Yan Wang, Guicheng He, Zhuoli Zhou, Dengke Wang, Dongming Zhang
Summary: Research on permeability models is important for understanding the evolution of methane seepage from coal seams and preventing gas accidents. Existing models do not fully consider the effects of stress and adsorption/desorption on permeability during coal mining. This study proposes a new permeability model based on Hooke's law and Gibbs' equation and validates it through triaxial stress loading-unloading seepage experiments. The results show that stress loading and unloading significantly affect coal permeability and the established model accurately reflects these effects, providing theoretical support for gas permeability prediction and efficient coalbed methane recovery.
Article
Geochemistry & Geophysics
Rui Yang, Lv Jiakun, Bo Zhou, Depeng Ma
Summary: The mechanical response characteristics and occurrence mechanism of coal and rock under unloading conditions are crucial for evaluating the stability and control of rock excavation in engineering. Fractal characteristics of coal and rock acoustic emission time series were analyzed to predict the unloading failure of coal and rock. In addition, the HURST index was calculated to determine the unloading and fracture process of rock samples.
Article
Geosciences, Multidisciplinary
Jun Tang, Jie Zhu, Tangsha Shao, Jinge Wang, Yaodong Jiang
Summary: Fracture compressibility and strain conditions play a crucial role in coal permeability evolution. The new permeability model derived in this study, considering variable fracture compressibility, showed more accurate results compared to the model with constant fracture compressibility. Coal fracture compressibility generally decreases with increasing effective stress and responds differently to changes in gas pressure and type.
NATURAL RESOURCES RESEARCH
(2021)
Article
Geochemistry & Geophysics
Yongfei Li, Baoyun Zhao, Jiaosheng Yang, Junchang Sun, Wei Huang, Ziyun Li, Bingyuan Wang
Summary: This study investigated the effects of bedding angles on the mechanical properties and failure characteristics of coal through experiments and numerical simulations. It was found that bedding angles have a significant influence on the mechanical properties of coal, and the properties of peak strength at different bedding angles exhibit a U-shaped changing trend.
Article
Engineering, Geological
Zhonghui Wang, Bobo Li, Chonghong Ren, Jianhua Li, Qiaoyun Cheng, Xuehai Wu, Chunhong Yao
Summary: This study establishes a theoretical basis for evaluating the safety and stability of underground engineering by investigating changes in rock strength and failure. Through triaxial compression experiments and energy evolution analysis, the deformation behavior and failure characteristics of coal have been revealed. Additionally, a damage constitutive model based on energy dissipation has been proposed to predict the deformation and failure of coal under different conditions.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Geological
Bang-an Zhang
Summary: In this study, experiments were conducted using a gas-containing coal thermal fluid-solid coupling three-axis servo seepage experiment device to analyze the deformation and permeability characteristics of raw coal with variable confining pressure unloading rate. It was found that the axial strain rate was higher than the permeability, while the radial strain rate was lower. The influence of axial stress and confining pressure on the deformation and permeability of specimens was significant during loading and unloading processes, with axial stress having a greater impact on axial strain and confining pressure affecting permeability. As the axial stress level and confining pressure unloading rate increased, the change rates of axial strain, radial strain, and permeability also increased gradually.
GEOTECHNICAL AND GEOLOGICAL ENGINEERING
(2022)
Article
Environmental Sciences
Tingen Zhu, Wenping Li, Jiawei Tian, Yi Cheng, Zhenmeng Lv
Summary: The creep deformation and permeability evolution of the paleoweathered rock in the K-1/J(2) unconformity contact zone under triaxial unloading-loading confining pressure were studied. The results provide valuable information for understanding leakage from Cretaceous aquifers and regional water-level decline. The creep strain and permeability show different patterns during the confining pressure unloading and loading stages, with the average creep rate and permeability being affected by clay mineral contents and deviatoric stress.
ENVIRONMENTAL EARTH SCIENCES
(2023)
Article
Geochemistry & Geophysics
Zhaoying Chen, Guofu Li, Yi Wang, Zemin Li, Mingbo Chi, Hongwei Zhang, Qingling Tian, Junhui Wang
Summary: The gas permeability evolution in tectonic coal samples under triaxial loading-unloading stresses was investigated in this study. The results showed that the gas permeability of the coal samples was correlated with the volumetric strain change during compression. The permeability decreased as the initial gas pressure increased and rapidly increased after the sample failed during stress releasing.
Article
Geosciences, Multidisciplinary
Yubing Liu, Enyuan Wang, Changbao Jiang, Dongming Zhang, Minghui Li, Beichen Yu, Dong Zhao
Summary: During deep underground coal mining, the mechanical and permeability characteristics of initially fractured coal were investigated under true triaxial stresses. The results show that initially fractured coal exhibits semi-brittle Class I failure modes and forms new failure planes different from intact coal samples. The peak strength of initially fractured coal is observed when the maximum principal stress is perpendicular to bedding planes, while minimum values occur when the maximum principal stress is parallel to butt cleats. The permeability of initially fractured coal decreases due to the presence of pulverized coal grains.
NATURAL RESOURCES RESEARCH
(2023)
Article
Engineering, Mechanical
Yaoyao Meng, Hongwen Jing, Xiaowei Liu, Qian Yin
Summary: This study investigates the strength, micro crack distribution, and energy evolution characteristics of stratified rock mass under unloading confining pressure conditions. Triaxial compression tests and triaxial unloading confining pressure tests were conducted at various initial unloading levels. The results indicate that the triaxial unloading confining pressure plus axial stress corresponds to a stress path between uniaxial compression and triaxial compression. As the initial unloading level increases, the specimen approaches the stress state of triaxial compression, resulting in linear increases in peak stress, peak axial strain, peak circumferential strain, and peak volume strain, and a linear decrease in Poisson's ratio. The failure type of specimens exhibits four typical characteristics. Additionally, when the bedding plane inclination is 45 degrees, 3D reconstruction and quantitative characterization of micro cracks were performed based on CT scanning results. The variations of area fraction along the specimen height displayed three typical characteristics. The stratified rock mass primarily stores and dissipates energy before the peak stress and releases and dissipates energy after the peak stress under different conditions. Furthermore, the input energy, elastic energy, dissipative energy, and energy dissipation rate at the peak stress increase approximately linearly with the increasing initial unloading level.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Engineering, Chemical
Feng Du, Kai Wang, Gongda Wang, Yifeng Jiang, Chengpeng Xin, Xiang Zhang
JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES
(2018)
Review
Engineering, Chemical
Ang Liu, Kai Wang, Jie Zang, Feng Du, Aitao Zhou
TRANSPORT IN POROUS MEDIA
(2018)
Article
Energy & Fuels
Kai Wang, Zhen Lou, Guoying Wei, Weidong Lu, Feng Du, Binbin Qin
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2020)
Article
Geosciences, Multidisciplinary
Kai Wang, Feng Du
ARABIAN JOURNAL OF GEOSCIENCES
(2019)
Article
Energy & Fuels
Kai Wang, Liang Wang, Xiang Zhang, Zhou Lou, Chengpeng Xin, Feng Du
ENERGY EXPLORATION & EXPLOITATION
(2019)
Article
Engineering, Environmental
Feng Du, Kai Wang
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2019)
Article
Chemistry, Multidisciplinary
Xiang Zhang, Kai Wang, Feng Du, Zhen Lou, Gongda Wang
APPLIED SCIENCES-BASEL
(2019)
Review
Engineering, Environmental
Kai Wang, Feng Du
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2020)
Article
Materials Science, Multidisciplinary
Ji Ma, Feng Du, Shuai Zhang
ADVANCES IN MATERIALS SCIENCE AND ENGINEERING
(2020)
Article
Geosciences, Multidisciplinary
Feng Du, Kai Wang, Xiang Zhang, Chengpeng Xin, Longyong Shu, Gongda Wang
NATURAL RESOURCES RESEARCH
(2020)
Article
Acoustics
Haiyan Wang, Gongda Wang, Guojun Zhang, Feng Du, Ji Ma
SHOCK AND VIBRATION
(2020)
Article
Construction & Building Technology
Haiyan Wang, Ji Ma, Feng Du, Gongda Wang, Quan Zhang, Xiaoshen Li
ADVANCES IN CIVIL ENGINEERING
(2020)
Article
Energy & Fuels
Chengpeng Xin, Feng Du, Kai Wang, Chao Xu, Suguo Huang, Jianting Shen
Summary: Understanding the damage evolution and gas-solid coupling behaviors of coal containing gas is crucial for recognizing the underlying mechanisms of coal and gas outburst. By establishing a damage factor expression based on energy conservation theory, the study reveals the critical damage factors and residual strength of loaded coal containing gas under various stress paths, providing practical significance for gas-solid coupling models.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2021)
Article
Engineering, Civil
Feng Du, Kai Wang, Yangyang Guo, Gongda Wang, Liang Wang, Yanhai Wang
GEOMECHANICS AND ENGINEERING
(2020)
Article
Engineering, Geological
Kai Wang, Xiang Zhang, Feng Du, Chengpeng Xin, Liang Wang
GEOTECHNICAL AND GEOLOGICAL ENGINEERING
(2020)