Article
Geosciences, Multidisciplinary
Yuepeng Sun, Biao Li, Linlu Dong, Haoyu Mao, Nuwen Xu, Zhongping Zhu, Jinfei Liu
Summary: The failure processes and mechanism of the surrounding rock mass can be effectively analyzed through MS monitoring with moment tensor analysis. Different regions of the surrounding rock mass showed varying failure types and stress states.
GEOMATICS NATURAL HAZARDS & RISK
(2021)
Article
Computer Science, Interdisciplinary Applications
Yuan Zhao, Guoyan Zhao, Jing Zhou, Ju Ma, Xin Cai
Summary: The combination of acoustic emission and moment tensor simulation is effective in analyzing rock failure mechanisms, with critical values for distinguishing implosion, shear, and tensile mechanisms identified and shown to be more accurate than counting microcracks for identifying rock failure mechanisms. Quantitative determination of macrocrack fracture mechanisms can be achieved through the distribution curve of AE events.
COMPUTERS AND GEOTECHNICS
(2021)
Article
Construction & Building Technology
Lu Wang, Luqi Wang, Yang Yang, Xing Zhu, Dong Zhang, Xuecheng Gao
Summary: This study conducted numerical simulations using the discrete element method (DEM) to investigate the failure mechanism and mechanical properties of rock-concrete bi-materials. The results showed that the nominal tensile strength depended on the rock type, with intact specimens having a higher loading capacity than hollow specimens. Different failure modes were observed in intact limestone-concrete bi-materials based on the interface angle, while the inclination angle had minimal effect on the failure pattern of sandstone-concrete bi-materials.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Mechanical
Yike Dang, Zheng Yang, Xiaoyu Liu, Jianghao Guo
Summary: This study uses discrete element modeling to examine bedded rock failure with parallel defects. It is found that bedding influences crack propagation direction but has limited impact on final failure. Shear failure accumulates at the bridge area and defect tip, while tensile failure occurs during nucleation region development.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Construction & Building Technology
Haoran Li, Shirong Meng, Dongping Shi, Qun Wei, Zhuang Xu, Weigang Zhao
Summary: This study aimed to improve the safety of concrete structures by investigating the mechanical properties and failure mechanism of concrete specimens with different moisture contents. Uniaxial compression tests were conducted on concrete specimens with moisture contents of 0%, 2%, 4%, and 5.5%. The results showed that crack initiation stress and compressive strength initially increased and then decreased with increasing moisture content, while elastic modulus and Poisson's ratio initially decreased and then increased. The study also analyzed the ultrasonic propagation, acoustic emission characteristics, and deterioration mechanism of bearing capacity in water-saturated concrete. The findings can be applied to health monitoring and safe operation of concrete structures in water environments.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Geological
Kunbo Wu, Junpeng Zou, Yu-Yong Jiao, Xiufeng Zhang, Chao Wang
Summary: Strong seisms triggered during deep coal mining pose a serious threat to the safety of underground miners and ground residents. Investigating focal mechanisms and source parameters of seisms is essential for understanding rock fracturing and rupture scale. However, such research is lacking in deep mines. This study analyzed over 11,000 seismic events in Dongtan Coal Mine and proposed a new criterion for determining rock fracture type. The formation mechanisms of strong seisms in mines were categorized and the correlation of source parameters was revealed.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Mechanics
Wei Sun, Shunchuan Wu
Summary: The Brazilian test is widely used to obtain the indirect tensile strength of geo-materials, but contact conditions and rock heterogeneity can affect the accuracy of the results. Laboratory tests showed that crack initiation points tend to occur away from the center of the disc, leading to a potential underestimation of the tensile strength. Analysis of acoustic emission sources revealed that tensile micro-cracks with deviatoric components predominantly occurred during micro-failure events.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Geochemistry & Geophysics
Amandine Amemoutou, Patricia Martinez-Garzon, Grzegorz Kwiatek, Justin L. Rubinstein, Marco Bohnhoff
Summary: The significant increase in seismicity rates in the USA over the past 10 years is attributed to the injection of wastewater from oil and gas production. A study on induced earthquakes in southern Kansas reveals that their source mechanisms are related to injection activity and local stress fields. The orientation of fault geometries in relation to the stress field show that small stress perturbations caused by water injection could lead to failure.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Mechanics
Xiaoran Wang, Pouyan Asem, Chen Hu, Joseph F. Labuz
Summary: Acoustic emission and digital image correlation were used to monitor mode I fracture, revealing local mixed-mode dominance due to oblique microcrack planes within a tortuous fracture. Mechanisms in the global coordinate system mainly indicated mode I opening.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Chemistry, Physical
Jie-Fang Song, Cai-Ping Lu, Zhao-Wei Zhan, Hai-Feng Cui, Yan-Min Wang, Jian-Hua Wang
Summary: This study analyzes the relationships among force, acoustic emission, and energy during coal fracture, revealing the microscopic damage mechanism of coal under different conditions. The numerical simulation results are consistent with field investigations, validating the rationality of the simulation. These results provide important reference for safety production evaluation of water inrush mines.
Article
Geochemistry & Geophysics
Han Li, Xu Chang, Jinlai Hao, Yibo Wang
Summary: This study compared the DC, GD, and MT models for single-well focal mechanism inversions and found that the GD model can provide reliable solutions from near-vertical data, which will aid in improving non-DC earthquake studies.
BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA
(2021)
Article
Engineering, Geological
Chun-Hui Song, Cai-Ping Lu, Xiu-Feng Zhang, Chao Wang, Hua-Dong Xie, Xian-Yang Yan, Hong-Wei Yang
Summary: Based on the Dongtan coal mine, this study investigates the failure mechanism and stress evolution characteristics of irregular coal pillars in a specific working face. The research findings provide important references for analyzing the mechanisms of coal pillar failure and induced rockbursts.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Geochemistry & Geophysics
Gene A. Ichinose, Sean R. Ford, Robert J. Mellors
Summary: Combining rotational motions with translational displacements improves the inference of radiation patterns in MT inversions.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Engineering, Geological
Qiang Xie, Chunbo He, Yuxin Ban, Xiang Fu, Zhihui Wu, Zhilin Cao
Summary: Understanding the cracking characteristics of shale is crucial for tunnel engineering and oil and gas exploitation in shale. This study found that the bedding plane angles and prefabricated flaws significantly influence the cracking behavior of shale specimens. The bedding plane reduces shear cracks when its direction is close to the loading direction.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2022)
Article
Mechanics
Huilan Ren, Shuizhou Song, Jianguo Ning
Summary: The acoustic emission technique and moment tensor inversion were used to study and quantify the damage evolution process and intensity of microcracks in Brazilian and flattened Brazilian concrete tests. The results showed that microcracks gradually propagate from the zones between the loading points and center to the center and loading points in the Brazilian test. In the flattened Brazilian test, the initiation positions of microcracks were random and crack accumulation occurred near the center of the specimen when the first peak load was reached.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Engineering, Multidisciplinary
Longjun Dong, Xiaojie Tong, Ju Ma
Summary: Detecting abnormal regions in complex structures in underground space engineering is a challenging task. By utilizing an improved 3D tomography method and combining passive acoustic emission acquisition with active ultrasonic measurements, it is possible to accurately and quantitatively identify and image abnormal regions, thereby improving detection reliability.
Article
Mathematics
Longjun Dong, Lingyun Zhang, Huini Liu, Kun Du, Xiling Liu
Summary: The b value of acoustic emission is an important parameter for predicting rock fractures. This study analyzed the changes in b value during rock failure and investigated the characteristics of acoustic emission events. The results showed that b value calculated using the average amplitude had higher accuracy, and an interval of event counts of 200 was suggested for b value calculations. The study also found that the b value decreased before fracture and decreased with increasing confining pressure.
Article
Engineering, Multidisciplinary
Yichao Rui, Zilong Zhou, Xin Cai, Longjun Dong
Summary: In this paper, a robust method for acoustic emission source location is proposed using the DBSCAN principle. The method calculates source coordinates and clusters them to improve location accuracy, and the results show its effectiveness and robustness.
Article
Chemistry, Analytical
Yueyuan Su, Longjun Dong, Zhongwei Pei
Summary: Damage detection is crucial for maintenance of automated machines. This paper proposes an acoustic emission tomography method that combines the fast sweeping method and the limited-memory Broyden-Fletcher-Goldfarb-Shanno method to detect cavity damage in automated machines. The results show the effectiveness of this new approach in real-time detection of cavity damage in continuous and homogeneous materials.
Editorial Material
Green & Sustainable Science & Technology
Longjun Dong, Yanlin Zhao, Wenxue Chen
Article
Geochemistry & Geophysics
Jinchun Xue, Zhuyu Zhao, Longjun Dong, Jiefang Jin, Yingbin Zhang, Li Tan, Ruoyan Cai, Yihan Zhang
Summary: Both chemical corrosion and axial compression have critical influences on the internal microstructure of rock, as well as the physical and mechanical properties. The strength of rock resistance to impact failure reaches its maximum when the pH of the solution is 7 and the axial pressure is 12.6 MPa. Acidic and alkaline environments are harmful to rocks during the initial impact, while neutral environments have little effect.
Article
Mathematics
Feiyue Wang, Xin Xie, Zhongwei Pei, Longjun Dong
Summary: A time-difference adjoint tomography method was developed and its effectiveness was validated through numerical experiments and laboratory-scale acoustic experiments. The method shows higher efficiency and robustness compared to traditional methods, providing clearer indications of anomalous areas in rocks.
Article
Mathematics
Daoyuan Sun, Yifan Wu, Longjun Dong, Qiaomu Luo
Summary: This study proposes a new method for locating heat-concentrated sources using temperature differences and simplifying nonlinear location equations through analytical solutions, which improves the accuracy of localization. Through numerical examples, it is shown that the proposed analytical solutions have higher accuracy compared to iterative methods. This method can be applied to heat source localization in more complicated conditions.
Article
Engineering, Environmental
Fang Yan, Longjun Dong, Bing Wang, Ji Ge, Ben Wang
Summary: A novel risk calculation method named RM based on field theory is proposed to improve the accuracy and reasonability of 3D risk assessments in the chemical industry. Case study results of fire and explosion accidents demonstrate the effectiveness of RM in providing more accurate results.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2022)
Article
Engineering, Geological
Longjun Dong, Longbin Yang, Yongchao Chen
Summary: Microseismic/acoustic emission (MS/AE) location technology is a powerful means to study the spatial evolution characteristics of rock fracture and early warning of geological hazards. This study used the velocity-free MS/AE source location method to investigate the variation in MS/AE location accuracy and the spatial evolution characteristics of granite fracture under complex stress conditions. The results showed that the variation of wave velocity caused by granite fracture is a key factor for the variation of location accuracy. The study also found consistency and difference in the evolution process and results of granite microcracks under uniaxial and biaxial stress conditions.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Chemistry, Analytical
Longjun Dong, Huanyu Zhu, Fang Yan, Shuijin Bi
Summary: In this study, a rock instability risk field model using microseismic monitoring data is proposed to create effective risk management. The rock instability risk is presented visually in 3D visualization. The in-situ microseismic monitoring data is collected and analyzed to calculate peak ground velocity (PGV), peak ground acceleration (PGA), energy flux, energy, and seismic moment. The weights of PGV, PGA, and energy flux are determined using the analytic hierarchy process (AHP) to calculate risk severity. The Copula function is used to solve the joint probability distribution function of energy and seismic moment. The spatial distribution characteristics of risk are obtained by data fitting, and a three-dimensional (3D) risk field model is established. The established risk field is verified by comparing monitoring data without disturbance and blasting data with disturbance. The proposed risk field method can reasonably and accurately evaluate the regional risk of rock instability, providing a theoretical foundation for the risk prediction and management of rock instability in deep mining.
Article
Environmental Sciences
Longjun Dong, Jiachuang Wang
Summary: Intelligent Safety Ergonomics (ISE) is a new direction for safety ergonomics in the era of big data, providing a deeper understanding of human-machine-environment systems and new research methods. This research not only helps safety researchers and practitioners to correctly understand the concept of ISE, but it also injects energy and vitality into the development of safety ergonomics and cleaner production.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2023)
Article
Engineering, Electrical & Electronic
Longjun Dong, Shuijin Bi, Yihan Zhang, Qingchun Hu, Huanyu Zhu
Summary: A new time picking method called the wavelet-STA/LTA-AIC (WSA) picker, which combines the advantages of wavelet transform, STA/LTA method, and Akaike information criterion, is proposed in this study. The performance of the WSA picker in picking arrival times is assessed by locating both artificial sources (pencil-lead breaking on marble panel) and natural sources (tensile cracking on granite). The WSA picker shows less location error compared to the AIC picker in all experiment results.
IEEE SENSORS JOURNAL
(2023)
Article
Metallurgy & Metallurgical Engineering
Long-jun Dong, Xian-hang Yan, Jian Wang, Zheng Tang
Summary: Combining microseismic multiparameter analysis, high-magnitude microseismic event distribution, and microseismic tomography, it is possible to effectively identify hazard precursor related to rockburst in underground mining. A self-developed microseismic monitoring system was implemented in a Shaanxi underground mine in China, and a correlation model was established between velocity anomalies and mining activity regions based on tomography results. Risk areas were determined by analyzing multiple parameters, including rock fracture parameter, MS activity, tomography results, high-magnitude microseismic event distribution, and in-site survey. The results showed that microseismic information can serve as an early warning identification of hazards and has wide future applications.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2023)
Article
Mining & Mineral Processing
Longjun Dong, Qing Tao, Qingchun Hu, Sijia Deng, Yongchao Chen, Qiaomu Luo, Xihong Zhang
Summary: This study presents an AE source location method for structures with unknown empty areas, increasing accuracy by identifying the shape, size, and location of empty areas. Experimental results demonstrate a 78% improvement in location accuracy compared to existing methods.
INTERNATIONAL JOURNAL OF MINING SCIENCE AND TECHNOLOGY
(2022)
