Article
Engineering, Multidisciplinary
Jinfeng Zou, Penghao Zhang
Summary: This study proposes a comprehensive model to predict the yield and failure patterns of rock bolts, highlighting the decoupling between the bolt and grout, as well as the yield and failure patterns of two potential points along the bolt through a combination of analytical and numerical methods.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Materials Science, Multidisciplinary
Ke Zhang, Kai Zhang, Wenlian Liu, Jianbin Xie
Summary: This article discusses the challenging problem of crack identification in brittle rocks in rock mechanics. Sand-based 3D-printed specimens were used to represent jointed rock masses, and digital image correlation was employed for deformation measurement. The study proposes a covariance matrix-based measure to quantify the dispersion of strain data and identifies different crack types based on strain dispersion variation. A new crack identification criterion is suggested based on the rates of mutation for tensile and shear cracks.
MATERIALS & DESIGN
(2023)
Article
Engineering, Mechanical
Wenhao Yi, Mingnian Wang, Siguang Zhao, Jianjun Tong, Chen Liu
Summary: The appearance of joints in rock tunnels affects the stability of the rock mass due to the anisotropy and discontinuity in its physical and mechanical properties. Mortar bolts, commonly used in tunnel construction, pass through these joints and their anchorage performance is influenced by rock hardness and rock mass integrity. This paper investigates the failure modes of joint rock and the failure modes of bolt-grout composite structure under different conditions of rock hardness and rock mass integrity through a mortar bolt pull-out experiment. Calculation formulas for the ultimate pull-out load and ultimate displacement of mortar bolts in joint rock are proposed by considering the influencing factors of rock hardness and integrity.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Geosciences, Multidisciplinary
Yuting Liu, Pengqiang Zheng, Pu Wang
Summary: A constitutive model of the coupling effect between bolt/cable and surrounding rock creep was established in this study, with results from numerical simulations verifying its validity. The main factors affecting anchorage force in creep rock include diameter, elastic modulus, and initial pre-stress force of bolt/cable, as well as viscoelastic parameters and initial in situ stress of surrounding rocks.
GEOMATICS NATURAL HAZARDS & RISK
(2021)
Article
Engineering, Chemical
Fulu Shang, Zelin Lu, Zhen Zhu, Xuchun Wang, Hao Ma, Mingqing Du, Peng Zhang, Sara Liparoti
Summary: This study compares the mechanical characteristics and supporting performance of lengthened anchored pre-stressed bolts, full-length anchored bolts, and full-length anchored pre-stressed bolts under bed separation conditions. Theoretical and numerical analysis models were established for the three types of bolts, and the effects of preload, bed separation values, bed separation numbers, and bed separation positions on the mechanical properties were studied. The results show that the initial preload has a significant restraining effect on the surrounding rock, with the full-length anchored pre-stressed bolt having a larger preload transmission range and better restraining effect. Under different bed separation conditions, the stress characteristics of the three types of bolts mostly follow the same trend except for the free section of the lengthened anchored pre-stressed bolt. The sensitivity analysis shows that the two types of full-length anchored bolts have higher sensitivity than the lengthened anchored pre-stressed bolt under left bed separation condition. There is little difference in sensitivity between the three types of bolts under middle and right bed separation conditions.
Article
Geosciences, Multidisciplinary
Zhen Yang, Wancheng Zhu, Kai Guan, Baoxu Yan, Wenjun Luo, Peng Liang
Summary: Anchor technology is essential in geotechnical engineering to reinforce jointed rock masses. This study investigates the effects of anchorage and the three-dimensional crack propagation process through physical model tests and numerical simulations. The results show that anchorage improves the compressive performance and deformation capability of jointed rock masses, controlling crack propagation and restraining shear zone formation. The optimal anchor opportunity varies with joint angle.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Construction & Building Technology
Shuai Fang, Hai Yan Zhang, Jiangxia Quan
Summary: This study investigated the anchorage behavior of geopolymer-grouted rock bolts and identified the factors influencing their anchorage performance. The experimental results showed that geopolymer grout provides better bonding than ordinary cement grout. Deformed bolts grouted with geopolymer exhibited better anchorage performance compared to plain round bolts, while bolt spacing of more than 150mm had little effect on anchorage performance. Increasing anchorage depth improved both the loading capacity and ductility but reduced the nominal bond strength of deformed bolts. The critical anchorage depth for achieving tensile failure of bolts was found to be 12d for both geopolymer-grouted and cement-grouted bolts.
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2022)
Article
Engineering, Civil
Ratan Das, Trilok Nath Singh
Summary: A parametric study was conducted to investigate the influence of different bolt parameters on maximum induced boundary displacements in jointed rockmass. It was found that increasing the bolt diameter substantially reduced the tunnel boundary displacement, while increasing bolt length did not significantly affect the boundary displacement for the same rockmass properties.
Article
Engineering, Geological
Xiaokun Xie, Jianchun Li, Yanlong Zheng
Summary: Impact tests were conducted on sandstone specimens with intersected and unjointed intact samples using a modified split Hopkinson pressure bar (SHPB) with confinement in order to study the dynamic mechanics and failure behavior of jointed rock masses. The effects of intersected artificial joints on the dynamic properties and failure mechanism of sandstone samples were analyzed. The results showed that the dynamic compressive strengths of both the unjointed intact rock specimens and the jointed rock specimens increased with the increase of the loading rate and the confining pressure. The jointed rock specimens exhibited more pronounced plastic deformation ability and smaller broken pieces compared to the intact rock specimens under higher loading rates.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Physics, Multidisciplinary
Long Yan, Zhipeng Xiang, Weiya Xu, Rubin Wang, Hua Ji
Summary: The deformation, strength characteristics, and failure modes of irregular columnar jointed rock masses (CJRM) under uniaxial compression were investigated using numerical simulation. It was found that irregular CJRM exhibit significant anisotropy, with compressive strength varying in a typical U-shape curve with joint angle. The failure modes of irregular CJRM can be classified as splitting failure, shear-sliding failure along columnar joints, and combined failure of column fracturing and joint splitting. The study demonstrates the effectiveness and reliability of numerical simulation in investigating the mechanical properties and failure mechanism of irregular CJRM.
FRONTIERS IN PHYSICS
(2022)
Article
Engineering, Geological
Hua Ji, Long Yan, Jianrong Xu
Summary: Columnar jointed rock mass (CJRM) has a unique joint structure formed during lava cooling, leading to mechanical anisotropy. The orientation of columns significantly affects the strength and deformation modulus of the rock mass, while increasing confining pressure changes the anisotropy in strength and deformation modulus.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2021)
Article
Engineering, Geological
Tao Zhang, Weiya Xu, Huanling Wang, RuBin Wang, Long Yan, MingTao Hu
Summary: The study investigated the anisotropic mechanical behavior of columnar jointed rock masses (CJRM) under different joint dip angles. Results showed that the relationship between stress thresholds and joint dip angles exhibited a typical U-shape, with mechanical parameters gradually increasing with stress, and three main failure modes observed during the loading process.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Engineering, Geological
Hyung-Koo Yoon, Jong-Sub Lee, Jung-Doung Yu
Summary: This study investigates the relationship between the longitudinal wave velocity in rock bolts and the physical and mechanical properties of granite rocks. The results show a significant correlation between the wave velocity and properties such as density, compressive strength, and modulus of elasticity. This suggests that the velocity of longitudinal waves in rock bolts can be used as an indicator to predict in-situ rock properties.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Materials Science, Characterization & Testing
Zhicheng Gong, Wendong Yang, Ling Wang, Lindong Fang, Weiteng Li, Yiwei Li
Summary: Bolt reinforcement can significantly improve the strength and modulus of jointed rock mass. The strength of the bolted rock-like specimen increases with the joint angle and decreases with the anchorage angle. The bolted specimens exhibit better ductility and integrity.
JOURNAL OF TESTING AND EVALUATION
(2023)
Article
Computer Science, Interdisciplinary Applications
Huanning Hu, Liyun Yang, Chun Feng, Xinguang Zhu, Jun Zhou, Xinming Liu
Summary: This paper describes the development process of the Continuum-Discontinuum Element Method (CDEM) and its application in studying stress wave propagation in jointed rock masses using the Barton-Bandis model (BB model). Simulation results demonstrate the accuracy and effectiveness of the CDEM in simulating stress wave propagation in jointed rock masses. This research provides important support for further understanding and analysis of stress wave propagation problems in jointed rock masses.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Engineering, Geological
Q. Yan, S. C. Li, C. Xie, Y. Li
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2018)
Article
Chemistry, Multidisciplinary
Yong Li, Weibing Cai, Xiaojing Li, Weishen Zhu, Qiangyong Zhang, Shugang Wang
APPLIED SCIENCES-BASEL
(2019)
Article
Engineering, Multidisciplinary
Zhongzhong Liu, Hanpeng Wang, Liang Yuan, Bing Zhang, Wei Wang, Zhengwei Ma, Yang Xue, Yong Li
Article
Engineering, Multidisciplinary
Yong Li, Hanpeng Wang, Weibing Cai, Shucai Li, Qiangyong Zhang
Article
Engineering, Geological
Bangxiang Li, Song Yu, Weishen Zhu, Weibing Cai, Lei Yang, Yiguo Xue, Yong Li
ROCK MECHANICS AND ROCK ENGINEERING
(2020)
Article
Engineering, Mechanical
Chao Wei, Yong Li, Weishen Zhu, Shucai Li, Shugang Wang, Hanpeng Wang
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2020)
Article
Engineering, Mechanical
Bang-Xiang Li, Song Yu, Wei-Shen Zhu, Lei Yang, Wei-Bing Cai, Yi-Guo Xue, Yong Li
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2020)
Article
Engineering, Mechanical
Zhiheng Wang, Yong Li, Weibing Cai, Weishen Zhu, Weiqiu Kong, Feng Dai, Chen Wang, Kai Wang
Summary: This study investigated the initiation mechanism of microcracks in fractured rock mass from the perspective of micromechanics, establishing macro-micro criteria to determine and distinguish the properties and types of cracks. It was found that the stress state of rock particles determines the type and propagation direction of cracks, allowing for an effective analysis of the initiation mechanism of different types of cracks and their propagation trends.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2021)
Article
Mechanics
Weiqiu Kong, Yong Li, Lichao Nie, Zhenxing Dong, Weibing Cai, Zhiheng Wang, Kai Wang
Summary: This paper investigates the crack propagation mechanism of rock-like specimens with preexisting flaws under the combined actions of internal hydraulic pressure and shear force through laboratory direct shear tests and discrete element theory. The results show that under internal hydraulic pressure, cracks propagate along the horizontal shear direction, leading to the appearance of shear and tensile cracks, ultimately reducing the shear strength of the cement mortar specimens.
ARCHIVE OF APPLIED MECHANICS
(2022)
Article
Engineering, Mechanical
Weibing Cai, Yong Li, Ke Gao, Kai Wang
Summary: Through experiments and numerical simulations, the mechanism of crack initiation, propagation, and coalescence in rock-like materials with intermittent flaws under shear loading was investigated. The results showed that cracks with different dip angles have a significant impact on the failure patterns of specimens.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Mechanical
Chen Wang, Yong Li, Feng Dai, Guannan Wu, Futong Yin, Kunpeng Li, Kai Wang
Summary: The study investigates the mechanical properties and failure mechanism of water-saturated fractured rocks at low temperature. The results show that low temperature, flaw morphology, and the presence of filled ice significantly affect the mechanical properties and failure characteristics of the rocks. This research provides valuable insights for engineering stability and safety in alpine regions.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Mechanical
Weibing Cai, Yong Li, Kai Wang
Summary: The mechanism of crack initiation, propagation, and coalescence in rock-like specimens with non-parallel flaws under shear loading and water pressure is investigated through laboratory experiments and discrete element simulation. The results show that the direction of crack propagation is parallel to the shearing loading for specimens with different flaw dip angles. The increase of water pressure leads to a more uniform stress field and weakened stress concentration near pre-existing flaw tips.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Mechanical
Futong Yin, Yong Li, Kunpeng Li, Shaowang Zhang, Chen Wang, Feng Dai, Kai Wang
Summary: The effects of fillers and the number of freeze-thaw (F-T) cycles on the mechanical behaviors and failure mechanism of flawed sandstone containing infillings are further investigated through F-T cycling and uniaxial compression tests. The experimental results show that fillers can effectively inhibit mass loss and pore growth, reduce stress concentration, and improve the strength of flawed specimens. As the number of F-T cycles increases, the peak stresses decrease and the cementation strength between rock particles decreases, causing particle loss and cracking failure. A deterioration failure mode for F-T failure of flawed specimens containing infillings is proposed based on the test phenomena.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Engineering, Geological
Wei Chao, Zhu Wei-shen, Li Yong, Wang Shu-gang, Dong Zhen-xing, Cai Wei-bing
ROCK AND SOIL MECHANICS
(2019)
Article
Engineering, Civil
Yong Li, Hao Zhou, Zhenxing Dong, Weishen Zhu, Shucai Li, Shugang Wang
GEOMECHANICS AND ENGINEERING
(2018)