Article
Engineering, Environmental
Linqi Huang, Yide Guo, Xibing Li
Summary: This study investigates the effect of high-temperature environment on shale failure characteristics through uniaxial compression tests and acoustic emission monitoring. The results show that shale specimens in both horizontal and perpendicular bedding directions experienced severe rockburst failure. The temperature had a significant effect on the rockburst characteristics of the specimens in both bedding directions.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2022)
Article
Geosciences, Multidisciplinary
Xuanhong Du, Junhua Xue, Qian Ma, Zhiheng Chen, Keliang Zhan
Summary: This paper focuses on the damage process of coal-rock composite bodies (CRCBs) under coal mine dynamic disaster. The results show that with an increase in coal thickness, the compressive strength and elastic modulus of CRCBs decrease while the peak strain increases, leading to a decrease in overall bearing capacity. The dissipated energy in the compaction stage accounts for a large proportion, while the accumulation of elastic energy dominates the elastic stage. After the plastic stage, the energy conversion rate accelerates, resulting in a rapid increase in dissipated energy and gradual failure of the samples. Coal is identified as the main energy storage structure of the whole coal and rock composite system.
NATURAL RESOURCES RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Ansen Gao, Chengzhi Qi, Renliang Shan, Chunlai Wang
Summary: This study investigates the spatial-temporal failure characteristics of discontinuities between rocks by conducting uniaxial compression tests on red sandstone specimens. The results show that adding a strong binder to rock discontinuities can enhance the shear strength and stability of rock mass. The stress curve demonstrates elastic-brittle failure characteristics of the red sandstone specimens, with no obvious plastic deformation. The acoustic emission ring counts exhibit different patterns at different stages of compression, and the types and locations of internal fractures also vary accordingly.
Article
Mechanics
Renshu Yang, Yuanyuan You, Jinjing Zuo, Yongliang Li, Yong Zhao, Jin Li
Summary: The study focused on the damage and destruction of remaining rock mass in rock blasting and investigated the impact of different decoupling ratios of the slit charges. By conducting blasting experiments and numerical calculations on glauconite specimens, the internal fracture and damage characteristics were quantified. The results showed that the degree of damage increased with the increase in the decoupling ratio, with the optimal ratio resulting in the smallest degree of damage. Numerical calculations also revealed that the peak effective stress of the blasthole wall was higher in the slit direction compared to the non-slit direction.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Environmental
Jieyu Li, Dongqiao Liu, Manchao He, Yunpeng Guo, Haosen Wang
Summary: In this study, a rockburst experimental system was developed to study rockburst precursors. The acoustic emission (AE) RA/AF, duration, and rise time during the rockburst process were analyzed. The findings suggest that the occurrence time of rockburst does not necessarily correspond to the peak stress point of the stress-strain curve, and the variance in AE values can be considered the main criterion for rockburst precursors.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2023)
Article
Thermodynamics
Beibei Yang, Mingming He, Zhanshan Xiao, Jianbin Zhao, Yonghao Zhang
Summary: With the increase in underground engineering depth, the risk of rockburst, a coal-rock dynamic disaster, is becoming more serious and complex, threatening the safety of coal resources. This study investigates the effect of horizontal stress on the fractal characteristics of rockburst fragments in coal mining. Experimental results show a positive correlation between the fractal dimension and the AEF (residual elastic energy index), indicating the potential for predicting rockburst propensity. The findings suggest that studying the AEF and fractal dimensions of fragments under different unloading conditions is theoretically relevant for understanding rockburst mechanisms.
Article
Energy & Fuels
Yi Xue, P. G. Ranjith, Yang Chen, Chengzheng Cai, Feng Gao, Xingguang Liu
Summary: Geological sequestration of CO2 is important for reducing global warming and achieving carbon neutralization. This study evaluates the effect of CO2 adsorption pressure on the mechanical properties of coal mass using experimental and analytical methods. An elastic damage model is established to describe the nonlinear stress-strain relationship of coal under CO2 adsorption. The results show that increasing adsorption pressure increases the risk of coal damage and fracturing, leading to a more complex fracturing process.
Article
Engineering, Multidisciplinary
Zilong Zhou, Congcong Zhao, Yinghua Huang
Summary: Nonlinear analysis is a powerful tool for studying instability and preventing disasters in rock mass engineering. A new method based on fractal theory is proposed to determine the fractal characteristics of the failure process using time series analysis. The time series analysis of fracture sources in the failure process of rock mass shows notable fractal characteristics. The advantage of this method is the better identification and classification of damage compared with traditional natural sequence frequency distribution.
Article
Energy & Fuels
Jing Yang, Zong-long Mu, Sheng-Qi Yang, Wen-ling Tian
Summary: The development and damage characteristics of microscopic cracks in a rock mass have a significant influence on the stability and engineering applications. The aggregation mode and expansion direction of high-energy AE sources affect the propagation direction of macroscopic cracks. The crack classification method reveals that tensile cracking dominates the crack development, and the macroscopic crack propagation becomes more complex with an increase in the proportion of microscopic shear cracks. The new damage evaluation index A(t) can better represent the internal damage of the rock.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Engineering, Geological
Jieyu Li, Dongqiao Liu, Manchao He, Yunpeng Guo
Summary: Fast unloading delayed rockburst experiments were conducted on different sides using a self-developed true triaxial rockburst experimental apparatus. The experiments investigated the stress-strain curve, energy evolution, failure characteristics, and acoustic emission (AE) characteristics. The results showed that increasing the number of unloading surfaces (NUS) gradually reduced the axial peak stress and strain. The rockburst intensity increased with the increase in NUS, indicated by the rise in axial strain at the fast unloading point and the cumulative AE hits at the burst point.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Geological
Jieyu Li, Manchao He, Dongqiao Liu, Davide Elmo, Jiamiao Zhang
Summary: A true triaxial double-sided rapid unloading rockburst experiment and a biaxial compression failure experiment without unloading were conducted to explore the effect of rapid excavation unloading under high pressure on delayed rockburst. It was found that rapid unloading before the occurrence of rockburst resulted in unloading damage, causing sudden increase in axial strain, acoustic emission (AE) count, and AE energy at the unloading point. The rapid unloading created many tensile cracks near the free surface, as confirmed by the AE source. Compared to biaxial compression, the axial peak stress of rockburst and the stored strain energy before failure were higher, leading to higher ejection velocity of free surface fragments at failure.
CANADIAN GEOTECHNICAL JOURNAL
(2023)
Article
Engineering, Environmental
Xiqi Liu, Gang Wang, Leibo Song, Guansheng Han, Wenzhao Chen, Hao Chen
Summary: Rockburst is a common geological disaster in deep rock excavation, and stress gradient plays an important role. In this study, the concept of stress concentration was proposed. By analyzing a large number of engineering rockburst cases, a new rockburst criterion considering the stress gradient of surrounding rock was established. The results showed that this criterion could effectively overcome the problem of non-uniform division in traditional criteria, and it had strong applicability with a prediction accuracy of over 90%. This proposed criterion has theoretical and practical value for the early warning of underground engineering disasters.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2023)
Article
Materials Science, Multidisciplinary
Changda Zheng, Renshu Yang, Qing Li, Chenxi Ding, Chenglong Xiao, Yong Zhao, Jie Zhao
Summary: This article studies the blasting damage of media with one free boundary and evaluates the damage based on fractal theory. The experimental and numerical simulation results show that the distance between blasthole and free boundary affects the efficiency of blasting energy destruction and the blasting failure pattern.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2022)
Article
Geosciences, Multidisciplinary
Xiaojun Feng, Zeng Ding, Yunqiang Ju, Qiming Zhang, Muhammad Ali
Summary: Coal mining in China has become more intense and complex in recent years, leading to severe rockburst disasters. This article focuses on the study of fracture characteristics and acoustic emission signal response of coal mass under dynamic loading. The results provide valuable insights for predicting and controlling rockburst in coal mines.
NATURAL RESOURCES RESEARCH
(2022)
Article
Construction & Building Technology
Fengqiang Gong, Jinhao Dai, Lei Xu
Summary: In this study, qualitative and quantitative analysis of 1114 rockburst cases was conducted. It was found that rockburst occurs more frequently in hard, complete, dry, and unweathered rocks. The Human-Rock-Environment three-element mechanism of rockburst was proposed, and the rationality and defects of the traditional strength-stress ratio criterion were investigated. A strength-stress coupling criterion was then proposed, which showed higher accuracy compared to the traditional criterion.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)