Article
Multidisciplinary Sciences
Yang Liu, Jian-Hua Wang, Cai-Ping Lu, Chao Wang, Hua-Dong Xie, Xian-Yang Yan
Summary: This study investigated the slip and instability mechanisms of coal-rock parting-coal structures under uniaxial loading conditions using experiments and case verification. The findings are relevant for the early warning of coal-rock dynamic disasters in coal mines.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Han Meng, Liyun Wu, Yuzhong Yang, Fei Wang, Lei Peng, Lei Li
Summary: The mechanical properties of briquette coal and raw coal samples are improved by confining pressure, with 20% cement content briquette coal being the closest to the raw coal samples in terms of mechanical and AE characteristics through triaxial compression experiments.
Article
Chemistry, Multidisciplinary
Zhongxi Zhu, Chaofei Wang, Zhigang Guan, Wanneng Lei
Summary: When drilling in hot dry rock, thermal stress can cause cracks to appear around the borehole, with crack propagation related to the stress intensity factor at the crack tip and the crack opening width. The linear expansion coefficient has a stronger effect on the peak value of thermal stress. Deeper cracks around the borehole are less influenced by the drilling fluid temperature.
Article
Engineering, Geological
Yanjiang Chai, Linming Dou, Wu Cai, Piotr Malkowski, Xuwei Li, Siyuan Gong, Jinzheng Bai, Jinrong Cao
Summary: Coal burst, a destructive manifestation of stratigraphic structure, is influenced by the mining stress environment and the roof stratum. This study investigates the damage and failure process of composite specimens, focusing on the mechanical response and damage evolution of coal and rock under cyclic loading. The results show that the mechanical behavior of the specimens is influenced by the mechanical properties and interactions of the components, and the damage state can be well reflected by the proposed dynamic elastic strain energy index and the variation in acoustic emission energy rate. The failure pattern of the specimens changes with increasing roof strength, from initial structural instability to the ejection of localized coal chips near the interface.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Han Meng, Yuzhong Yang, Liyun Wu
Summary: The addition of binders in briquette coal changes its properties, but different binders show high consistency in failure characteristics. Briquette coal samples with 7% rosin have more similarities in strength, deformation, and acoustic emission features with raw coal samples compared to other binder contents.
Article
Geosciences, Multidisciplinary
Xiaobin Li, Haoteng Wang, Ying Zhao, Haifang Xue, Lingyun Li
Summary: In this study, a new metric called the post-peak dissipated energy index is proposed to evaluate the rock burst proneness of a rock mass, taking into account strain rate and size effects. Compression tests were conducted on limestone and slate samples with different length to diameter ratios and strain rates. The results showed that higher strain rates led to a stronger hardening effect and staged growth of rock burst proneness, while the rock burst proneness decreased non-linearly with increasing length to diameter ratio. The proposed energy-based index provided a reliable evaluation of rock burst proneness and has great potential for practical application in deep rock engineering.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Qian Yin, Xinxin Nie, Jiangyu Wu, Tianci Deng, Hongwen Jing, Bo Meng, Liyuan Yu
Summary: Layered rock-like samples with saw-tooth interfaces of various joint roughness co-efficients and included angles were subjected to uniaxial compression. The study analyzed the changes in peak stress, peak strain, failure modes, and local strains under different conditions.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Engineering, Geological
Weiyao Guo, Dongxiao Zhang, Tongbin Zhao, Yurong Li, Yongqiang Zhao, Cunwen Wang, Wenbin Wu
Summary: The stability of coal-rock composite structures is crucial for coal mine production safety. Uniaxial cyclic loading-unloading tests were conducted on gypsum-rock combination specimens to investigate the failure characteristics and energy evolution law of the composite structures. The tests revealed that the peak stress and elastic modulus of the combination specimens increased linearly with increasing rock strength and failure intensity. Furthermore, as the rock strength increased, the energy accumulation rate of the combination specimens decreased, but the total accumulated energy increased before the prepeak stress. The energy evolution processes of the rock component and gypsum component were similar to the combination specimen.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2022)
Article
Engineering, Environmental
Chunxiao Li, Dejian Li, Xiaolin Liu
Summary: Investigating the effect of the redistribution of radial surrounding rock stress field on rock burst characteristics is important during the excavation of deep underground engineering. A series of true triaxial rock burst experiments were conducted on granite under intermediate principal stresses with various intensities. The experimental results indicated that an increase in the intensity of the intermediate principal stress led to a delay and then acceleration in the evolution of damage severity within the specimen. Additionally, the rock burst failure modes transformed from tensile-shear failure to predominantly shear failure.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2023)
Article
Acoustics
Xinggang Xu, Hao Feng, Lishuai Jiang, Tao Guo, Xingyu Wu, Zequan Sun
Summary: The study shows that under high stress and dynamic load disturbance conditions, the deformation and failure of the surrounding rock during the connection of deep rock burst drivage roadway are significant, with the roof being the most affected. The main factor affecting the deformation of the surrounding rock is the plastic damage of the coal seam roof.
SHOCK AND VIBRATION
(2021)
Article
Engineering, Mechanical
Peng Feng, Bo Liu, Ran Tang, Mingdong Wei, Yan Zhang, Huajin Li
Summary: This study investigated the mechanical behaviors of sandstone with two non-coplanar flaws under coupled static-dynamic loads. The results showed that the dynamic strength and coupled strength of the flawed sandstone were influenced by the static pre-stress. Different loading conditions resulted in different failure modes and degree of crushing destruction. Additionally, the fracture process zones and higher-order stress terms cannot be ignored in analyzing the crack behavior of flawed rocks.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Xiaohui Liu, Yang Xue, Yu Zheng, Hongying Li
Summary: Research on early warning of rock disaster based on the energy theory is important for understanding the essence of rock failure. This study conducted static compression tests and acoustic emission (AE) tests on coal rock under different confining pressures. The energy evolution law in the rock failure process was analyzed, and a new index based on energy dissipation rate (EDR) was proposed for evaluating rock failure precursors. The results showed that EDR had a good correlation with mechanical strength and AE events, and could accurately characterize the deformation and failure characteristics of coal rock.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Yongchen He, Pengxiang Zhao, Shugang Li, Chun-Hsing Ho, Sitao Zhu, Xiangguo Kong, Diego Maria Barbieri
Summary: The study found that the mechanical characteristics and energy dissipation of coal-rock composite specimens are significantly affected by the rock-coal strength ratios. With the increase of strength ratios, the failure mode of the specimens changed, with coal failure playing a crucial role in the final failure process.
NATURAL RESOURCES RESEARCH
(2021)
Article
Geosciences, Multidisciplinary
Zhoujie Gu, Rongxi Shen, Zhentang Liu, Xin Zhou, Xiaoliang Li, Zesheng Zang, Li Zhang, Wei Liu, Xi Wang
Summary: By using the split Hopkinson bar system, the mechanical behavior and energy change of coal were analyzed, and it was found that cracks were produced along the axial direction of coal samples under dynamic loading. The damage degree of coal samples intensified gradually within a certain range of strain rate. A dynamic mechanical constitutive model considering the influence of strain rate was established, and the damage changes of coal samples were analyzed.
NATURAL RESOURCES RESEARCH
(2023)
Article
Energy & Fuels
Kun Zhong, Wusheng Zhao, Changkun Qin, Weizhong Chen
Summary: This study highlights the influence of bedding structures on the mechanical properties and failure behaviors of coal, shedding light on the mechanism of high-risk rock bursts.