Article
Geochemistry & Geophysics
Xiujun Liu, Zhanguo Ma
Summary: A method for analyzing the mechanical behavior of fully grouted bolts, called the spring element method, is proposed in this study. The load-transfer model of fully grouted bolts is established using this method, and analytical solutions are given. It is found that the model is suitable for two working conditions: lambda approximate to 0 and lambda approximate to 1.
Article
Computer Science, Interdisciplinary Applications
Lin Zhang, Meng Wang, Hongbo Zhao, Xu Chang
Summary: An uncertainty quantification method was developed to consider the uncertainties in rockbolt performance by integrating experimental data, rockbolt properties, and a mechanical model. The method combines the Bayesian method and data from two rockbolt pull-out tests, and successfully predicts the rockbolt performance and improves the understanding of its mechanical mechanism.
COMPUTERS AND GEOTECHNICS
(2022)
Article
Mathematics, Interdisciplinary Applications
Zhihong Dong, Xu Wu, Xun Xi, Li Jun, Peitao Wang, Li Peng, Jiliang Pan
Summary: The corrosion of rockbolt has a significant impact on the long-term performance of anchoring structures. This study presents a novel numerical method to investigate the pull-out failure of corroded rockbolt. The results show that as the corrosion develops, the bond strength and critical displacement decrease, and the effect of corrosion on strength reduction is more significant under higher confining pressure.
COMPUTATIONAL PARTICLE MECHANICS
(2023)
Article
Engineering, Chemical
Shuisheng Yu, Yawei Wang, Honghao Yang, Shucan Lu
Summary: This study investigates the load transfer behavior, energy dissipation, failure mode, and failure mechanism of grouted rockbolt systems from the perspective of energy. The experimental results show that the failure process of grouted rockbolt systems is closely related to the accumulation and release of energy.
Article
Metallurgy & Metallurgical Engineering
Yun-lou Du, Guo-rui Feng, Hong-pu Kang, Yu-jiang Zhang, Xi-hong Zhang
Summary: The mechanical performance of fully grouted bolts is significantly influenced by the pull-out loading rates, with an increase in pull-out loading rates resulting in higher maximum pull-out loads and lower displacement and time at maximum load. Acoustic emission counts, energy, and events decrease with higher pull-out loading rates.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2021)
Article
Chemistry, Analytical
Jiahe Liu, Dongsheng Li, Xiushi Cui
Summary: In this paper, a guided-wave-based structural health monitoring method is used to detect debonding in grouted sleeves (GSs). The relationship between the arrival time of the first wave packet and the debonding size is explored through theoretical derivation, numerical simulation, and experimental results.
Article
Construction & Building Technology
Haiyang Gao, Lianguang Wang, Xue Li, Yaosheng Zhang
Summary: This study investigates the pull-out behaviors of wedge-grouted rockbolts and grouted rockbolts in different weathered rocks. The test results show that the minimum anchoring length varies in strongly weathered and moderately weathered rocks for both types of rockbolts. The effect of wedge head on restraining deformation is related to the anchoring length. Freeze-thaw cycle has little influence on the stiffness and deformation of the rockbolts. The wedge-grouted rockbolts exhibit better deformation performance compared to grouted rockbolts. Furthermore, the calculation models provide reasonable predictions for strain and shear stress development.
INTERNATIONAL JOURNAL OF STEEL STRUCTURES
(2023)
Article
Engineering, Geological
Emad Jahangir, Laura Blanco-Martin, Faouzi Hadj-Hassen, Michel Tijani
Summary: This paper proposes a new interface constitutive model for fully grouted rock-bolts and cable-bolts based on pull-out test results, which accounts for friction mobilization and provides good agreement with experimental results. The model has been implemented in a finite element method code and numerical simulations have been performed, demonstrating its ability to assist in the design and optimization of bolting patterns.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2021)
Article
Geosciences, Multidisciplinary
Hao Shen, Jinhui Li, Sixin Wang, Zewei Xie
Summary: In an era of developing large-scale underground infrastructures, the need for better prediction of the load-displacement performance of grouted anchors is increasing. This paper introduces FastICA-MARS as a novel data-driven approach for this purpose, which outperforms the classical MARS method in providing accurate predictions. By integrating the FastICA algorithm with the MARS technique, the developed model considers the importance of parameters such as grouting pressures, which is essential in engineering practices.
GEOSCIENCE FRONTIERS
(2021)
Article
Engineering, Geological
Are Havard Hoien, Charlie C. Li, Ning Zhang
Summary: The study investigates the pull-out mechanism of fully grouted bolts under different embedment conditions, identifying three failure mechanisms and their corresponding loading conditions. The research results show that the embedment length of bolts is crucial, including elastic deformation length, plastic deformation length, and completely debonded length.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Acoustics
Shuisheng Yu, Leilei Niu, Jin Chen
Summary: The research investigates the impact of in situ stress on rockbolt support by conducting laboratory tests and numerical simulations to understand the effects of pull-out load and confining pressure on the propagation law of ultrasonic guided waves.
SHOCK AND VIBRATION
(2022)
Article
Mathematics, Interdisciplinary Applications
Hao Shi, Houquan Zhang, Wenlong Chen, Lei Song, Ming Li
Summary: This study established a rockbolt pull-out model considering the physical existence of ribs and the distribution of pre-cracks in cement mortar using PFC2D software. The influence of distributed cracks on the debonding characteristics of rockbolts, including crack development, peak load, failure scheme, and contact forces, were investigated through theoretical analysis and numerical simulation. The results showed that the anti-pull load of rockbolts had weak correlation with the uniaxial compressive strength (UCS) of the standard specimen under symmetrical prefabricated distributed cracks, and the overall strength and failure characteristics of rockbolt-cement mortar were predominantly determined by the weaker side with more or larger cracks under asymmetrical pre-cracks.
COMPUTATIONAL PARTICLE MECHANICS
(2023)
Article
Engineering, Civil
Yunlou Du, Guorui Feng, Hongpu Kang, Yujiang Zhang, Xihong Zhang
Summary: Through laboratory research, it was found that steel fiber grout can effectively improve the bearing performance of anchored specimens, enhancing their anti-destructive ability. The steel fibers in the grout can enhance mechanical interlocking, dilatancy, and friction effects, thereby improving the ability of the anchored specimens to withstand additional loads.
Article
Construction & Building Technology
Saman Khaleghparast, Naj Aziz, Alex Remennikov, Sina Anzanpour
Summary: This study aims to improve the understanding of the performance of conventional rock bolts under shear loading, especially dynamic loading conditions. Static tests were conducted to examine the effect of internal confinement and evaluate energy absorption. The dynamic response of the rock bolts was assessed using a drop hammer. The results showed that using steel tubes for internal confinement prevented concrete cracking and allowed for more shear resistance. The shear performance under high-velocity impact load was found to be 70% of that under static loading conditions.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)
Article
Geochemistry & Geophysics
Xiujun Liu, Zhanguo Ma
Summary: In this study, a load transfer model of the fully grouted ground anchor is established using the spring element method, and the analytical solutions of the displacement, axial force, and shear stress distribution of the ground anchor are provided for the upper and lower parallel strata foundation and sandwich foundation. The mechanical behavior of the vertical fully grouted ground anchor in the soft-hard alternating stratum is analyzed under different conditions. The results show that the mechanical behavior of the ground anchor is greatly influenced by the shear modulus of the shallow stratum, while the influence of the shear modulus of the deep stratum is relatively small. The depth of the stratum interface and the thickness of the interlayer have some influence on the mechanical behavior of the ground anchor, but little influence on the displacement and axial force distribution.
Article
Construction & Building Technology
Chen Hou, Wancheng Zhu, Baoxu Yan, Kai Guan, Jiafa Du
CONSTRUCTION AND BUILDING MATERIALS
(2020)
Article
Engineering, Geological
Feng Dai, Wancheng Zhu, Leilei Niu, Chen Hou, Yongjun Yu, Kai Guan
Summary: The study investigates the sliding instability of a rock block triggered by dynamic disturbance during mining excavation. The experimental results show that the key block's vertical displacement can be divided into three modes post-disturbance, with two distinct instability processes observed once it begins to fall. The critical impact energy causing the key block to fall increases logarithmically with the lateral clamping load.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Engineering, Geological
Xige Liu, Wancheng Zhu, Penghai Zhang, Lankun Li
Summary: Uniaxial compressive tests on Y-jointed granite specimens revealed that as the uniaxial compressive strength of the specimens increased, different failure modes appeared, including shear failure, compressive failure, and overall crushing, each with different ac thresholds. The joint dip angle and joint roughness were found to significantly influence the strength of the specimens.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Engineering, Geological
Shuai Li, Wancheng Zhu, Leilei Niu, Kai Guan, Tao Xu
Summary: The study used a double-rock sample to simulate the interaction between roof and pillar, and found the impact of dynamic disturbance on the creep process. The granite sample did not fail during loading, while the plastergranite and granitegranite samples failed in different ways.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Engineering, Geological
Hangyu Dong, Wancheng Zhu, Chen Hou, Xige Liu
Summary: This study conducts compressive tests on treble-pillar specimens under soft and stiff loading conditions to reveal the load transfer mechanism during cascading pillar failure. The experimental results show that the load transfer behavior of treble-pillar specimen is influenced by the energy storage characteristics of the test machine and the mechanical properties of the rock specimens. Three failure modes are summarized for treble-pillar specimen under soft loading condition. A theoretical model is proposed to explain the physical mechanism of load transfer behavior, and it is in good agreement with the experimental results. It is concluded that the elastic deformation and rapid elastic rebound of near-field surrounding rockmass are necessary conditions and physical essence for load transfer among pillars. This study contributes to understanding the load transfer mechanism among pillars and optimizing the design of room-and-pillar stopes in underground mining.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Engineering, Geological
Xige Liu, Wancheng Zhu, Yangxiao Liu, Kai Guan
Summary: The 3D reconstruction of rock joint surfaces is crucial for quantifying rock joints. The study used statistical distributions and a bubbling method to reconstruct the surfaces, providing important references and results.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Engineering, Geological
Wancheng Zhu, Baoxu Yan, Xige Liu, Zhen Yang, Kai Guan
Summary: A damage-based creep model was established to quantify the impact of dynamic disturbances on rock creeping. Numerical simulations and case studies showed that dynamic disturbances could accelerate damage and deformation of creeping rock, affecting the stability of shaft.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2022)
Article
Energy & Fuels
Wancheng Zhu, Xiufeng Zhang, Shuyuan Liu, Chenhui Wei, Jiangmei Wang, Heyang Liu
Summary: This paper introduces a self-developed experimental apparatus for fracturing rock specimens, which can be used to validate the performance and feasibility of the apparatus.
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2022)
Article
Geochemistry & Geophysics
Hangyu Dong, Wancheng Zhu, Kai Guan, Xige Liu, Chen Hou
Summary: This study investigates the mechanism of unstable pillar failure, which is one of the most hazardous problems in underground mining engineering. Laboratory tests, numerical simulation, and theoretical analysis were conducted to study the post-peak failure behavior of rock specimens and the elastic rebound behavior of disc spring groups. The results show that the loading stiffness of the testing machine has a significant effect on the rock specimen's failure behavior, with a decrease in loading stiffness leading to more severe rock unstable failure. The numerical simulation successfully reproduced the rock unstable failure and the elastic rebound behavior, supporting the experimental results. By using catastrophe theory, the necessary condition of rock unstable failure and the analytical solution of deformation and elastic energy release were derived. This study reveals important insights into the physical essence of unstable pillar failure, which can contribute to understanding the mechanism of pillar rockburst and provide references for underground mining.
Review
Energy & Fuels
Wancheng Zhu, Shuyuan Liu, Xiufeng Zhang, Chenhui Wei
Summary: This paper provides a comprehensive review of the mechanisms and properties of gas adsorption in coal, the geomechanical behavior of coal, and the mechanisms of gas transport in coal. It also discusses several waterless fracturing techniques for improving coalbed permeability and identifies current knowledge and research gaps.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Energy & Fuels
Fuchao Tian, Zhengdong Liu, Wancheng Zhu, Weiwei Su, Jiaxuan Wang, Jiamei Yang, Zheng Zhang
Summary: This study investigates the dynamic combined effect of coal mass diffusion and seepage on methane migration under different in situ stress conditions. By constructing the physical structure model of coal mass under high and low stresses and obtaining the diffusion parameters of coal mass, the methane migration in coal mass was calculated using a coupled multifield model. The results demonstrate that the extraction difficulty of methane is directly proportional to stress, and there is a significant discrepancy in methane migration under high and low stresses. A joint technical method for promoting methane flow rate under multicoal seam conditions is proposed based on the controlling factors in methane migration.
Article
Environmental Sciences
Wenxing Wang, Weiyu Huang, Xiufeng Zhang, Wancheng Zhu, Shihao Guo, Ang Li
Summary: During hydraulic fracturing, exogenous microorganisms enter the shale gas reservoir, but the effects of microbial activity on the process are not well understood. In a laboratory simulation, a brine-shale-microorganism interaction was studied for 150 days. Biogenic methane production was rapid in the initial 16 days, slowed down from day 16 to day 40, and ceased after day 40, accompanied by alkalization of the brine. The formation of biogenic methane appeared to be independent of substrate type. This study also found that biofilms accelerated mineral dissolution, facilitated secondary mineral formation, and enhanced the complexity and heterogeneity of macropore structure.
GEOMICROBIOLOGY JOURNAL
(2023)
Article
Metallurgy & Metallurgical Engineering
Chen Hou, Wan-cheng Zhu, Bao-xu Yan, Liu-jun Yang, Jia-fa Du, Lei-lei Niu
Summary: This paper analyzed the load-bearing capacities and failure modes of backfilled pillars through biaxial compression tests and investigated the combined effects of lateral stress, fill ratio, and backfill mechanical properties. The results showed that the interface friction force and effective backfill strength increased faster than pillar strength with lateral stress gain, leading to an increase in the load capacity of the backfilled pillar. Additionally, the stiffness difference between the pillar and backfill resulted in lower effective backfill strength in biaxial loading tests compared to uniaxial compressive strength. The increase of lateral stress not only improved the interface friction and effective backfill strength but also affected the failure modes of the pillar and backfill. The experimental results are valuable for studying the interaction of pillar-backfill structure.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2023)
Article
Energy & Fuels
Zhengdong Liu, Xinhui Chen, Fuchao Tian, Wancheng Zhu, Ze Hu, Weiwei Su, Zhiquan Wang
Summary: Fractures in coal seams play a crucial role in gas migration and their geometric characteristics can affect permeability, thus impacting coalbed methane (CBM) extraction and carbon dioxide sequestration. Previous research has mainly focused on surface characteristics of rough fractures, with less attention given to the dynamic effects of rough structure in fractures during different stages of methane extraction. In this study, a physical model of fracture rough elements was constructed and a definition of effective fracture aperture was proposed. By considering the competition between effective stress and matrix adsorption expansion, the change of effective fracture aperture related to pore pressure was determined. A permeability evolution model was formulated and compared with numerical simulations for verification. The findings indicate that fractures with smaller roughness, higher stagger degree, and gentler inclination angle of rough elements are more favorable for CBM extraction.
GAS SCIENCE AND ENGINEERING
(2023)
