Numerical Investigation of the Pull-Out and Shear Mechanical Characteristics and Support Effectiveness of Yielding Bolt in a Soft Rock Tunnel
Source abstract
Abstract
Conventional bolts frequently fail under large deformations due to stress concentration in soft rock tunnels. In contrast, yielding bolts incorporate energy-absorbing mechanisms to sustain controlled plastic deformation. This study employed FLAC3D to numerically investigate the pull-out, shear, and bending behaviors of yielding bolts, evaluating their support effectiveness in soft rock tunnels. Three-dimensional finite difference models incorporating nonlinear coupling springs and the Mohr–Coulomb criterion were developed to simulate bolt–rock interactions under multifactorial loading. Validation against experimental pull-out tests and field measurements confirmed the model accuracy. Under pull-out loading, the axial forces in yielding bolts decreased more rapidly along the bolt length, reducing stress concentration at the head. The central position of the maximum load-bearing capacity in conventional bolts fractured under tension, resulting in an hourglass-shaped axial force distribution. Conversely, the yielding bolts maintained yield strength for an extended period after reaching it, exhibiting a spindle-shaped axial force distribution. Parametric analyses reveal that bolt spacing exerts a greater influence on support effectiveness than length. This study bridges critical gaps in understanding yielding bolt behavior under combined loading and provides a validated framework for optimizing energy-absorbing support systems in soft rock tunnels.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Rock Mechanics and Modeling · Geotechnical Engineering and Underground Structures · Geotechnical Engineering and Analysis
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
China Academy of Safety Science and Technology, No. 32 Beiyuan Road, Beijing 100012, China
Chinese Association of Automation, No. 95 Zhongguancun East Road, Beijing 100190, China
School of Mechanics and Civil Engineering, China University of Mining and Technology at Beijing, D11 Xueyuan Road, Beijing 100083, China
Funding
Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project · National Natural Science Foundation of China · Fundamental Research Funds for China Academy of Safety Science and Technology
References (40)
Show source-provided references
1. Roof Stability Analysis of Cylindrical Tunnels in Hard Soil/Soft Rock with Reduced Tension Strength10.1016/j.compgeo.2023.105838 ↗
2. Fatigue Behaviour and Constitutive Model of Yellow Sandstone Containing Pre-Existing Surface Crack under Uniaxial Cyclic Loading10.1016/j.tafmec.2020.102776 ↗
3. Failure Modes and Excavation Stability of Large-Scale Columnar Jointed Rock Masses Containing Interlayer Shear Weakness Zones10.1016/j.ijrmms.2022.105222 ↗
4. Experimental Study on Mechanical Properties, Permeability and Energy Characteristics of Limestone from through-Coal Seam (TCS) Tunnel10.1016/j.enggeo.2022.106673 ↗
5. Strength and Failure Characteristics of Jointed Rock Mass with Double Circular Holes under Uniaxial Compression: Insights from Discrete Element Method Modelling10.1016/j.tafmec.2020.102692 ↗
6. Moore, K.S., and Vlachopoulos, N. (2024). Effects of Rib Spacing and Grout Annulus on Grouted Rock Bolt Performance Utilizing Fiber Optic Strain Sensing. Appl. Sci., 14.10.3390/app14052136 ↗
7. Effect of Dynamic Loading Conditions on the Dynamic Performance of MP1 Energy-Absorbing Rockbolts: Insight from Laboratory Drop Test10.1016/j.ijmst.2022.09.023 ↗
8. Dynamic Performance of Energy-Absorbing Rockbolts Based on Laboratory Test Results. Part I: Evolution, Deformation Mechanisms, Dynamic Performance and Classification10.1016/j.tust.2020.103510 ↗
9. Tahmasebinia, F., Zhang, C., Canbulat, I., Vardar, O., and Saydam, S. (November, January 29). A Numerical Study of the Behaviour of Fully Grouted Cable Bolts under Static and Dynamic Loading. Proceedings of the ISRM International Symposium-10th Asian Rock Mechanics Symposium, Singapore.
10. The Influence Law of Eccentric Load on the Performance of Yielding Bolt10.1098/rsos.200227 ↗
11. Mechanical Performance of Rock Bolts under Combined Load Conditions10.1016/j.ijmst.2020.01.004 ↗
12. Mechanical Behavior and Failure Mechanisms of Rock Bolts Subjected to Static-Dynamic Loads10.1016/j.ijmst.2024.02.007 ↗
13. The Mechanism of the New-Type Yielding Bolt
14. Experimental and Analytical Investigation of the Shear Resistance of a Rock Joint Held by a Fully-Grouted Bolt and Subject to Large Deformations10.1016/j.trgeo.2021.100671 ↗
15. Mechanical Behavior Analysis of Fully Grouted Bolts under Shear throughout the Entire Elastic–Plastic Process10.1016/j.engfailanal.2025.109340 ↗
16. Morido-García, G., and De Santos-Berbel, C. (2024). Structural Performance of Bolted Lateral Connections in Steel Beams under Bending Using the Component-Based Finite Element Method. Appl. Sci., 14.10.3390/app14093900 ↗
17. A Critical Review on the Performance of Yielding Supports in Squeezing Tunnels10.1016/j.tust.2021.103815 ↗
18. Wang, T., Liu, H., Kang, M., Zhao, B., Shen, J., Li, Y., and Yang, Y. (2024). Study on the Synergistic Effect of Primary Support and Surrounding Rock of Large Buried Depth Tunnel in Soft and Fractured Strata. Appl. Sci., 14.10.3390/app14052028 ↗
19. Characterizing Large Deformation of Soft Rock Tunnel Using Microseismic Monitoring and Numerical Simulation10.1016/j.jrmge.2024.05.029 ↗
20. Failure Mechanism and Deformation Prediction of Soft Rock Tunnels Based on a Combined Finite–Discrete Element Numerical Method10.1016/j.compgeo.2023.105622 ↗
21. Xu, J., Wen, H., Sun, C., Yang, C., and Rui, G. (2022). Numerical Simulation of Non-Stationary Parameter Creep Large Deformation Mechanism of Deep Soft Rock Tunnel. Appl. Sci., 12.10.3390/app12115311 ↗
22. Peng, W. (2014). FLAC3D Practical Tutorial, China Machine Press. (In Chinese).
23. Numerical Investigation Study on Tensile-Shear Failure Behavior of Rock Bolts in Inclined Strata Mining Tunnels10.1016/j.engfailanal.2024.108393 ↗
24. Experimental and Numerical Study on the Effect of Load Direction on the Bolt Loosening Failure10.1016/j.engfailanal.2024.108574 ↗
25. Numerical Simulation on Pull-Tests of a Cable by FLAC3D
26. Explicit Reinforcement Models for Fully-Grouted Rebar Rock Bolts10.1016/j.jrmge.2016.07.006 ↗
27. A Numerical Study to Investigate the Influence of Surface Roughness and Boundary Condition on the Shear Behaviour of Rock Joints10.1007/s10064-019-01710-z ↗
28. FLAC3D Numerical Simulation Study on the Failure Developing Law of Interface for Geotechnical Prestressed Anchorage Bolt10.4028/www.scientific.net/AMR.671-674.50 ↗
29. Zhang, S., Jiang, Y., Zheng, H., Wu, X., and Chen, H. (Comput. Part. Mech., 2025). Shear Characteristics and Damage Mechanisms of the Bolt–Grout Interface under Cyclic Shear Loading, Comput. Part. Mech., Early Access.10.1007/s40571-025-00953-w ↗
30. Laboratory Investigations into the Failure Mechanisms of New Yielding and Inflatable Rockbolts Under Axial and Shearing Loading Conditions10.1007/s00603-022-03086-1 ↗
31. Ma, L., Xing, L., Liu, C., Cui, T., Qiao, X., Miao, W., and Kong, P. (2025). Research on the Instability Mechanism and Control Technology of Gob-Side Entry in Deep Mines with Soft Rock. Buildings, 15.10.3390/buildings15010019 ↗
32. A Review of Experimentation and Computational Modeling of Dynamic Bolt Fracture10.1016/j.jcsr.2022.107293 ↗
33. Analysis of Deformation Characteristics of Fully Grouted Rock Bolts Under Pull-and-Shear Loading10.1007/s00603-020-02108-0 ↗
34. Performance of a New Yielding Rock Bolt Under Pull and Shear Loading Conditions10.1007/s00603-019-01779-8 ↗
35. Design Approach and Its Optimization for Bolted Steel Plate Strengthened RC Beams Considering the Effect of Connection Bolt Slip10.1016/j.istruc.2023.105045 ↗
36. Wang, C., Zheng, X., Xin, W., Wang, J., and Liu, L. (2025). Investigation of Bolt Support Mechanisms and Parameter Optimization for Hard Roof Control in Underground Mining. Processes, 13.10.3390/pr13010094 ↗
37. Croccolo, D., De Agostinis, M., Fini, S., Khan, M.Y., Mele, M., and Olmi, G. (2023). Optimization of Bolted Joints: A Literature Review. Metals, 13.10.3390/met13101708 ↗
38. Ministry of Housing and Urban-Rural Development of the People’s Republic of China (2014). General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China, Standard for Engineering Classification of Rock Masses, (In Chinese).
39. Evaluation of New Austrian Tunnelling Method Applied to Bolu Tunnel’s Weak Rocks10.1016/j.jrmge.2019.12.011 ↗
40. Frame Structure Analysis Model of Tunnel Lining Using Nonlinear Ground Reaction Curve10.1016/j.tust.2019.103135 ↗