Article
Mechanics
Mengyang Zhai, Lei Xue, Hongran Chen, Chao Xu, Yuan Cui
Summary: The study found that the shear rate significantly affects the failure process and AE characteristics of layered rocks. Increasing shear rate leads to higher average released AE energy, while decreasing total AE number and b-values, indicating faster crack propagation and more high-energy AE events.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Environmental Sciences
Zhenlong Zhao, Hongwen Jing, Xinshuai Shi, Jiangyu Wu, Qian Yin
Summary: The study found that the uniaxial compressive strength, elasticity modulus, and peak strain of rock are significantly dependent on strain rate. Different strain rates result in varying failure modes and acoustic emission characteristics in rock, while the microscopic fracture morphology plays a crucial role in rock mechanical behaviors.
ENVIRONMENTAL EARTH SCIENCES
(2021)
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
Engineering, Civil
Mehrdad Imani, Hamid Reza Nejati, Kamran Goshtasbi, Amin Nazerigivi
Summary: The failure patterns and crack evolution mechanism of rock specimens provide valuable information about their mechanical properties. This study explores the influence of brittleness on the failure mechanism of rock specimens through experimental and numerical examinations. The results show that highly brittle specimens exhibit tensile axial splitting failure mode and contain more tensile fractures during loading.
SMART STRUCTURES AND SYSTEMS
(2022)
Article
Materials Science, Multidisciplinary
Xuebin Gu, Weiyao Guo, Chengguo Zhang, Xiufeng Zhang, Chuanqing Guo, Chao Wang
Summary: This study investigates the mechanical and acoustic emission evolution characteristics of coal-rock composite specimens with different interfacial angles. The results show that peak stress and elastic modulus decrease as the interfacial angle increases, with a shift in failure mode from matrix splitting to interface slip failure. Acoustic emissions can be used as precursors of instability in coal-rock composite specimens.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Mathematics, Interdisciplinary Applications
Jie Liu, Qiuping Li, Xiaoran Wang, Zaiquan Wang, Shouqing Lu, Zhanyou Sa, Hao Wang
Summary: This study investigates the instability mechanism of composite coal-rock samples with different strength rock through uniaxial compression experiments and analysis of acoustic emission (AE) characteristics. The results reveal the influence of rock strength on the failure mechanism and energy evolution of composite samples. The findings demonstrate that the variation of AE characteristics reflects the changing crack propagation mode of the samples during deformation, and the increase in rock strength alters the dominant mechanism of crack propagation.
CHAOS SOLITONS & FRACTALS
(2022)
Article
Multidisciplinary Sciences
Han-dong Liu, Jing-jing Liu, Shi-ying Zhang, Ling-yun Feng, Lei Qiu
Summary: This study investigated the influence of fracture angles and connectivity on the deformation and failure of soft rock-like material through uniaxial compression tests and acoustic emission measurements. The differences between fractured and intact material were mainly observed during post-peak failure stage, and the fracture angle and connectivity affected the uniaxial compressive strength of fractured soft rock-like material.
SCIENTIFIC REPORTS
(2022)
Article
Acoustics
Jianqing Jiang, Guoshao Su, Zhaofu Yan, Zhi Zheng, Xiaochuan Hu
Summary: Understanding crack development in rocks is crucial for understanding different types of rock failures. This study employed acoustic emission pattern identification and feature indexes to detect and identify tensile and shear crack types. The proposed approach was found to be feasible and helpful in understanding the process of rock failure.
Article
Engineering, Geological
Cheng Lyu, Jianfeng Liu, Zhide Wu, Hejuan Liu, Fukun Xiao, Yin Zeng
Summary: A series of tests were conducted to investigate the mechanical properties, permeability, and AE characteristics of gypsum under different confining pressures and temperatures. The results showed that an increase in confining pressure and temperature inhibited the formation of microcracks and pores, leading to a decrease in permeability. The AE peaks also exhibited a hysteresis effect similar to stress peaks, with an increase in AE ring count observed at higher temperatures under a confining pressure of 35 MPa.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Engineering, Mechanical
Shijie Li, Daoxue Yang, Zhen Huang, Qixong Gu, Kui Zhao
Summary: This study employed AE monitoring technology to analyze the acoustic characteristics and failure mode of yellow sandstone in BITT, UCT, and TCT. The results showed that the decrease in the AE b value corresponds to the sudden increase in AE energy before the peak stress. The distribution of peak frequency varies in different tests. By analyzing the parameters, different cracking modes can be classified. The research results provide some reference for studying the failure process of rocks under complex stress.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Multidisciplinary Sciences
Nazli Tunar Ozcan
Summary: Rock salt caverns are excellent hosts for storing oil, natural gas, radioactive and toxic wastes due to their low permeability and self-healing characteristics. In this study, the effects of temperature on the physical and geo-mechanical properties of Cankiri rock salt were investigated. The results show that the P-wave velocity and Brazilian tensile strength of the rock salt decrease with increasing temperatures, while the uniaxial compression strength increases. The ductility of the rock salt also increases with temperature, and the number of cracks and porosity in the rock samples increase significantly with higher temperatures.
Article
Construction & Building Technology
Zhiwei He, Kang Zhao, Yajing Yan, Fujin Ning, Yun Zhou, Yufeng Song
Summary: The study investigated the failure law of a cement paste backfill (CPB) and rock combination under pressure with different cement tailings ratios, finding significant influence of tailings content on crack evolution and acoustic emission characteristics at different stages of the CPB.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Geological
Kui Zhao, Daoxue Yang, Peng Zeng, Zhen Huang, Wenkai Wu, Bo Li, Tianye Teng
Summary: Increasing water content in rocks results in a decrease in strength and deformation, leading to potential geological disasters. This study investigated the impact of water content on rock failure patterns and acoustic emission characteristics in red sandstone. The findings provide valuable information for future risk assessment and disaster prevention efforts.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Engineering, Geological
Zhenghu Zhang, Ke Ma, Hua Li, Zhiliang He
Summary: In this study, a micro analysis of rock direct tensile failure was conducted using quantitative analysis of acoustic emission (AE) waveforms. The results show that the complexity of mineral composition corresponds to the dispersion degree of rock tensile strength. L-type waveforms carry more energy than H-type waveforms under tension. The peak strength of rock specimens shows a downward trend with increasing energy ratios of L-type waveforms. Micro shear fractures were observed during the macro tensile failure process. The determined tensile strength can be used as a conservative design parameter for rock engineering.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Chemistry, Physical
Jun Guo, Luyang Yu, Zhijie Wen, Guorui Feng, Jinwen Bai, Xiaoze Wen, Tingye Qi, Ruipeng Qian, Linjun Zhu, Xingchen Guo, Xincheng Mi
Summary: This study investigates the shear failure mechanism and influencing factors of coal-rock mass under dynamic and constant normal load. The results reveal that disturbance load decreases the shear strength and increases the shear modulus of the specimen. The dynamic load intensifies the internal damage of the specimen during the shear failure process, affecting the shear strength and fracture mode. The study highlights the importance of considering the influence of disturbance load on coal-rock mass strength in underground engineering.