Article
Geosciences, Multidisciplinary
Dongdong Pang, Kai He, Yatao Xu, Jucai Chang, Xingang Niu, Chuanming Li
Summary: This study established a mechanical model describing the interaction between a full-length anchorage bolt and surrounding rock using elastic mechanics and mathematical analysis methods. The mechanical formulas for calculating the axial force and shear stress of the bolt were derived. The model and analysis results were verified through experiments.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geochemistry & Geophysics
Deyu Qian, Hexi Jiao, Jinping Deng, Jingxuan Yang, Mingzhi Jiao, Guihong Xian, Chenshi Yu, Yingli Zhu, Jiale Liu, Sen Huang, Binyong Li
Summary: Double-roadway tunneling is important for the sustainable development of underground mines as it can alleviate the contradiction between mining production needs and tunneling speed. However, controlling the stability of mining roadways adjacent to strong mining disturbances caused by double-roadway tunneling is challenging, especially at large mining heights. In this study, field monitoring, theoretical analysis, numerical simulations, and engineering practice were conducted to identify the main factors influencing deformations and stress distribution in order to propose countermeasures. The results showed that factors like large mining height, repeated mining, stress concentration, and thin anchorage layers in the roof influenced the large deformation of mining roadways. Countermeasures such as pressure relief and long anchorage were effective in controlling the stability of a strong mining roadway.
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
Chemistry, Physical
Deyu Qian, Qi Cui, Hexi Jiao, Guanghui Zhu, Zhiyi Zhang, Linyou Jiang, Qingbin Meng, Jiale Liu, Xing Gao, Fujia Xing
Summary: This study analyzes the main influencing factors and mechanism of deformation and failure of argillaceous surrounding rock in a horsehead roadway using field measurements, laboratory experimentation, numerical simulation, and industrial tests. Control principles and countermeasures are proposed to ensure the stability of the roadway. The failure of the surrounding rock is caused by factors such as poor lithology, horizontal tectonic stress, additional stress from the shaft, and inadequate anchorage layer and floor reinforcement. The study suggests increasing the thickness of the anchorage ring, exceeding the minimum depth of floor reinforcement, and reinforcing key positions to control the argillaceous surrounding rock.
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
Construction & Building Technology
Xuwei Zhao, Keguo Sun, Qian Huang, Weiping Xu, Wenge Qiu, Shuqi Ma, Li Tang
Summary: In this paper, a mixed particle contact model based on the Parallel Bond model was proposed and applied in the study of pullout models. Pullout experiments were conducted to analyze the bearing capacity, failure characteristics, and interaction mechanism of the anchorage system, and to determine the reasonable anchorage length.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Dongping Zhao, Sixun Wen, Luwei Wang, Baihao Zhang, Liu Yang
Summary: This study investigated the structural parameters of BFRP anchor plate and rod, as well as the critical anchorage length of BFRP cement mortar anchor through meso-scale numerical simulation and laboratory tests. The findings provided new insights and optimal solutions for the application of Basalt Fiber System Bolts in tunnel engineering.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Geological
Ding Wang, Manchao He, Zhigang Tao, Aipeng Guo, Xuchun Wang
Summary: In this study, the deformation behaviors of twinning induced plasticity (TWIP) steel used for rock bolt under rock loading conditions were investigated. It was found that the loading rate significantly affects deformation-softening behavior, while the pretension plays a major role in the deformation-relaxation scenario.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2022)
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
Green & Sustainable Science & Technology
Qinzheng Wu, Huanxin Liu, Bing Dai, Li Cheng, Danli Li, Penghui Qin
Summary: Strengthening the base-angle of a roadway can improve its overall stability, but the optimal parameter range is still unclear. The stability analysis of different section shapes of roadways was conducted using FLAC3D software, and simulation verification was carried out at the Sanshandao Gold Mine. The study found that a tri-centric arch roadway has the best self-stability without support, while a rectangular roadway has the worst. A better supporting effect can be achieved when the base-angle bolt dip angle is between 15 degrees and 45 degrees. The paper provides reference for tunnel bottom corner bolt support parameter selection.
Article
Energy & Fuels
Peng Wang, Nong Zhang, Jiaguang Kan, Bin Wang, Xingliang Xu
Summary: This study analyzed the surrounding rock stability control for a floor rock roadway under an oblique straddle working face. Through in situ ground pressure monitoring and numerical simulation calculation, the influencing factors on the stability of surrounding rocks and the range of mining influence on the roadway surrounding rocks were identified.
Article
Engineering, Chemical
Zhengzheng Xie, Fengchun Mu, Feng Guo, Nong Zhang, Yongle Li, Ruiji Chen, Qinghua Chen
Summary: This study aims to explore the failure mechanism of surrounding rock under the influence of fault structures using field investigation and numerical simulation. The results show that stress concentration and low rock mass strength near the fault area may cause deformation and failure of the surrounding rock. The proposed hierarchical continuous support technology effectively restrains the deformation of the surrounding rock and reduces roadway deformation in the roof and two sides. The study also explores the necessity of wedge anchorage and the deformation characteristics of surrounding rock at different fault dip angles.
Article
Engineering, Chemical
Zaisheng Jiang, Shengrong Xie, Dongdong Chen
Summary: Conventional bolt-shotcrete support technology does not meet the requirements of strength and stiffness for roadway support. This paper proposes a new combined support technology, consisting of multiple layers of bolts, steel meshes, shotcrete, long cables, and grouting. The new technology achieves effective control of deep roadway intersections with large cross-sections.
Article
Geochemistry & Geophysics
Honghui Zhao, Haijian Su, Xiaofeng Qin, Kai Zhang, Yu Jiang, Wenbo Wang
Summary: Underground engineering such as mines, tunnels, and underground caverns is often affected by ground stress and mining disturbance, resulting in loosening and deformation of the roadway surrounding rock during excavation. Bolt support is commonly used to stabilize the surrounding rock. In this study, a simplified model of the anchorage rock mass was created, and laboratory compression tests and simulation using FLAC3D software were conducted to investigate the effectiveness of different bolt configurations and lateral pressure conditions on the stability of surrounding rock. The results showed that increasing the number of bolts and lateral pressure improved the stress distribution and coverage of the anchorage stress field, and increasing bolt pretightening force and decreasing row spacing enhanced the anchorage mechanical characteristics of the rock mass. These findings provide theoretical guidance for selecting appropriate bolt support parameters for roadway surrounding rock.
Article
Engineering, Geological
Jiong Wang, Peng Liu, Manchao He, Huanzhi Tian, Weili Gong
Summary: A combined support scheme using the NPR bolt as the core element was proposed to address the issue of large deformation in the deep soft rock roadway. Numerical simulation test and field support test verified the feasibility and effectiveness of the combined support scheme in controlling the large deformations. The results revealed the stress-strain relationship and mechanical behavior of the NPR bolt-anchored rock mass under different stress conditions.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
