Article
Engineering, Geological
Yanan Gao, Donghao Lan, Shengqi Yang, Peng Hou, Yunlong Wang, Feng Ding
Summary: A series of mechanical tests and acoustic emission (AE) monitoring were conducted to investigate the effects of disturbance stress paths, disturbance modes, and initial confining pressures (ICPs) on the behavior of engineering rocks. The fractal dimensions of AE temporal distribution (Dt) and spatial distribution (Ds) were calculated and analyzed, along with the normalized AE count. The results showed that the different disturbance modes had sensitive, inferior sensitive, and delayed sensitive effects on the AE activities, depending on the ICP. The damage severity of the disturbance modes followed the order of HD, MD, and LD modes under an ICP of 12.5 MPa. The changes in Dt and Ds were consistent with the sensitive effect. Under an ICP of 25 MPa, only the HD mode caused significant damage, while the LD and MD modes showed inferior sensitive effects. Similarly, under an ICP of 37.5 MPa, the late-period Ds showed significant differences among the three disturbance modes, indicating delayed sensitive effects. Overall, the study revealed that the damage propagation and mechanical behavior of engineering rocks were influenced by both the ICP and disturbance mode.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Mechanical
Kui Zhao, Xing Wang, Li Wang, Peng Zeng, Daoxue Yang, Jiefang Jin
Summary: This study investigates the influence of water on the crack and acoustic emission (AE) behavior evolution of red sandstone specimens during deformation and failure. Uniaxial compression tests were conducted under different water contents. The results show that the peak strength of red sandstone decreases with increasing water content, and the dominant failure pattern changes from tension to shear. The AE events rate can be used as a precursor for the instability and failure of rock specimens with different water contents.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Environmental
Hongjian Wang, Jin Li, Qiang Guo, Ruiguo Shi, Zijiang Zhao, Yitong Zhang, Fei Zhao
Summary: This study conducted a series of experiments to investigate the properties of sandstone, and found that the presence of water affects the crack development, fragment features, and damage evolution of sandstone, which have a significant impact on the evaluation of hydraulic fracturing effects.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(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
Construction & Building Technology
Jian Yang, Kang Zhao, Xiang Yu, Yajing Yan, Zhiwei He, Yun Zhou, Yanming Lai
Summary: The fracture evolution characteristics of fiber-reinforced backfill were explored through the analysis of amplitude correlation dimension, RA correlation dimension, and time of acoustic emission. The study found that the fiber-reinforced backfill exhibits good fractal characteristics, with the amplitude time series showing better fractal properties compared to the RA time series.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Engineering, Environmental
Weijing Xiao, Dongming Zhang, Shujian Li, Jun Lu, Yongxin Li
Summary: This paper conducted uniaxial compression tests on sandstone specimens after different temperature treatments to explore the fracture evolution of thermally damaged sandstone during loading, and collected acoustic emission signals. Based on the experimental results, the dynamic evolution of the rock fracture mode was analyzed, and nonlinear characterization parameters were calculated. The influence of temperature on the rock fracture evolution was also discussed. The research results can provide guidance for understanding the process of thermal damage to surrounding rock masses and analyzing their stability characteristics in engineering practice.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2023)
Article
Environmental Sciences
Pengfei Li, Qiang Sun, Shengli Tang, Delu Li, Tian Yang
Summary: The study found that high temperature and pore structure play important roles in affecting the emission rate of radon in rocks. As the temperature increases, the connectivity of internal pores improves, leading to a significant increase in radon emission rate. Additionally, the presence of micropores inhibits the emission of radon in sandstone.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Engineering, Mechanical
Wenbing Fan, Junwen Zhang, Weimin Niu, Yang Zhang, Xukai Dong, Yulong Xing, Weigang Zeng
Summary: The mechanical characteristics and energy evolution law of sandstone with double cracks under dynamic load were investigated using SHPB test system. The stress-strain curves and failure characteristics were obtained, and the effects of crack angle and impact pressure were analyzed. The results showed that the compressive strength of the specimen initially decreased and then increased with increasing crack angle, while it increased gradually with increasing impact pressure. Under dynamic loading, the failure mode changed from tensile failure to shear failure and then to tensile failure as the crack angle increased. The fractal dimension increased with increasing impact pressure, and increased and then decreased with increasing crack angle.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Environmental Sciences
Hongjian Wang, Zhendong Cui, Chong Xu, Rui Yong, Fei Zhao, Shangyuan Chen
Summary: Understanding the failure mechanisms of rocks exposed to different water contents is crucial for rock stability in engineering applications. Real-time acoustic emission (AE) technology was utilized to analyze the damage evolution in sandstone rocks under different water conditions. The results indicated that as water content increased, rock strength decreased and experienced less severe damage with fewer fractures. The findings of this study enhance our understanding of rock failure mechanisms and contribute to disaster assessment and control.
Article
Engineering, Mechanical
Ju Wang, Jiangteng Li, Zhanming Shi
Summary: Most engineering rock masses are under the interaction of fatigue load and creep load. Understanding of the fatigue or creep characteristics of rock is relatively mature, but the damage and failure characteristics under fatigue-creep interaction (FCI) are rarely studied. The study on red sandstone with prefabricated cracks showed that the elastic modulus tended to be stable, while the deformation modulus decreased nonlinearly after creep loading. Acoustic emission (AE) mainly occurred in the fatigue loading stage, and the level of AE increased with the crack angle. These research results have theoretical reference value for understanding the damage and failure characteristics of fractured rock mass under interaction.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Construction & Building Technology
Hexing Zhang, Kunpeng Lu, Wuzhou Zhang, Dalang Li, Genlan Yang
Summary: This study analyzed the changes in the mechanical properties and microstructure of sandstone under dry-wet cycles. Fractal dimension and correlation dimension were used to describe the microstructural features, and acoustic emission was used to assess the damage process of sandstone. The results showed that the mechanical properties of sandstone decreased as the number of dry-wet cycles increased, and microstructure damage was directly proportional to the fractal dimension. The analysis of correlation dimension and sandstone microscale failure provided insights into the fracture development trend and microstructural characteristics of sandstone.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Engineering, Geological
Hao Liu, Yujun Zuo, Zhonghu Wu, Wenjibin Sun, Lujing Zheng, Yili Lou, Jianyun Lin, Ruzhen Wan
Summary: This study utilized various technologies to characterize the microstructure of sandstone, and developed digital image processing technology for mesostructure characterization. By introducing fractal dimensions and mesoscale fracture damage degree, it successfully determined the failure modes and damage degree, helping to understand the mechanical properties of rocks.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2021)
Article
Geochemistry & Geophysics
Hongguang Ji, Dongsheng Chen, Xiaobo Su, Zhen Fu, Daolu Quan
Summary: Mining-induced earthquake is a common risk factor in mining engineering safety. This study analyzed the spatial multifractal characteristics and magnitude-frequency distribution of mine seismicity based on microseismic monitoring data from Huating Coal Mine. The results showed that mine seismicity exhibits obvious spatial multifractal characteristics and follows the Gutenberg-Richter law under high tectonic stress. The fractal dimension and b value are positively correlated, and the spatial distribution of mine seismicity is related to the magnitude-frequency distribution.
Article
Green & Sustainable Science & Technology
Xin Huang, Tong Wang, Yanbin Luo, Jiaqi Guo
Summary: The influence of water content on the mechanical properties of sandstone and the evolution of crack propagation were studied through laboratory compression tests and EDEM numerical simulation. The findings showed that as the water content in the samples increased, the peak strain increased but the peak strength, elastic modulus, maximum energy rate of individual acoustic emission events, and cumulative acoustic emission energy rate all decreased. The ratio of tensile cracks to shear cracks inside the rock samples increased with increasing water content, and the failure mode of sandstone changed from shear failure to tensile failure, although shear macroscopic fracture surfaces were observed in all three conditions. The research results will provide guidance for the safe construction of underground projects in water rich areas.
Article
Engineering, Geological
Shun Ding, Shibin Tang, Hailiang Jia, Yibao Li
Summary: This study investigates the failure characteristics and damage process of rocks soaked in water using nuclear magnetic resonance (NMR) and an ultrasonic system. The results show that the soaking time affects the water content, strength, and velocity of the rocks. In addition, an acoustic emission (AE)-uniaxial compression test was conducted to analyze the AE characteristics and strength of sandstone under different soaking times.
ENGINEERING GEOLOGY
(2023)
