Skip to main content
Log in

Theoretical and numerical study on reinforcing effect of rock-bolt through composite soft rock-mass

复合软岩穿层锚固效应的理论和数值模拟研究

  • Published:
Journal of Central South University Aims and scope Submit manuscript

Abstract

Anchoring mechanism and failure characteristics of composite soft rock with weak interface usually exhibit remarkable difference from those in single rock mass. In order to fully understand the reinforcement mechanism of composite soft roof in western mining area of China, a mechanical model of composite soft rock with weak interface and rock bolt which considering the transverse shear sliding between different rock layers was established firstly. The anchoring effect was quantified by a factor defined as anchoring effect coefficient and its evolution equation was further deduced based on the deformation relationship and homogenized distribution assumption of stress acting on composite structure. Meanwhile, the numerical simulation model of composite soft rock with shear joint was prompted by finite element method. Then detailed analysis were carried out for the deformation features, stress distribution and failure behavior of rock mass and rock bolt near the joint under transverse load. The theoretical result indicates that the anchoring effect of rock-bolt through weak joint changes with the working status of rock mass and closely relates with the physical and geometric parameters of rock mass and rock bolt. From the numerical results, the bending deformation of rock bolt accurately characterized by Doseresp model is mainly concentrated between two plastic hinges near the shear joint. The maximum tensile and compression stresses distribute in the plastic hinge. However, the maximum shear stress appears at the positions of joint surface. The failure zones of composite rock are produced firstly at the joint surface due to the reaction of rock bolt. The above results laid a theoretical and computational foundation for further study of anchorage failure in composite soft rock.

摘要

复合软岩的锚固机理及锚固失效特征不同于单一岩体锚固。 针对西部矿区复合软岩顶板锚固问题, 考虑岩层间的横向剪切滑移, 建立了含软弱界面复合软岩锚固的力学模型; 提出采用锚固效应因子量化穿层锚杆的锚固效应; 从加锚复合岩体的变形破坏过程出发, 研究了系统锚杆的加固效果与机理, 建立加固效果演化方程; 采用有限元方法, 进一步建立了复合软岩锚固的数值计算模型, 分析了岩体在横向载荷作用下, 节理面附近锚杆和岩体的变形特征、 应力分布规律以及破坏行为。 理论研究结果表明, 穿层锚杆的加固效应与锚杆的刚度参数、 几何参数, 围岩的刚度参数和几何参数据有关。 锚固效应因子是一个随着围岩工作状态改变而变化的量。 从数值计算结果看, 锚杆在横向荷载作用下的弯折变形主要集中在节理面附近的两塑性铰之间, 变形曲线可用 Doseresp 模型进行表征; 在 2 个塑性铰处, 锚杆存在最大拉压应力, 在节理面处, 出现最大剪应力, 复合岩体在节理面附近由于锚杆的反作用最先出现塑性破坏区。 以上结果为进一步研究复合软岩锚固失效奠定了理论和计算基础。

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. TAN Y L, LIU X S, NING J G, LU Y W. In situ investigations on failure evolution of overlying strata induced by mining multiple coal seams [J]. Geotechnical Testing Journal, 2017, 40(2): 1–14. DOI: https://doi.org/10.1520/GTJ20160090.

    Article  Google Scholar 

  2. ZHAO Z H, WANG W M, WANG L H. Theoretical analysis of a new segmented anchoring style in weakly cemented soft surrounding rock [J]. International Journal of Mining Science and Technology, 2016, 26(3): 401–407. DOI: https://doi.org/10.1016/j.ijmst.2016.02.006.

    Article  MathSciNet  Google Scholar 

  3. ZHANG Le-wen, WANG Ren. Research on status quo of anchorage theory of rock and soil [J]. Rock and Soil Mechanics, 2002, 23(5): 627–631. (in Chinese)

    MathSciNet  Google Scholar 

  4. PHILLIPS S. Factors affecting the design of anchorage sin rock [M]. London: Cementation Research Ltd., 1970.

    Google Scholar 

  5. MA S, NEMCIK J, AZIZ N. An analytical model of fully grouted rock bolts subjected to tensile load [J]. Construction and Building Materials, 2013, 49: 519–526. DOI: https://doi.org/10.1016/j.conbuildmat.2013.08.084.

    Article  Google Scholar 

  6. REN F F, YANG Z J, CHEN J F, CHEN W W. An analytical analysis of the full-range behavior of grouted rockbolts based on a tri-linear bond-slip model [J]. Construction and Building Materials, 2010, 24(3): 361–370. DOI: https://doi.org/10.1016/j.conbuildmat.2009.08.021.

    Article  Google Scholar 

  7. XIAO Shu-jun, CHEN Chang-fu. Mechanical mechanism analysis of tension type anchor based on shear displacement method [J]. Journal of Central South University of Technology, 2008(S1): 106–111. DOI: https://doi.org/10.1007/s11771-008-0021-z.

    Article  Google Scholar 

  8. HE Si-ming, LI Xin-po. Study on mechanism of prestressed anchor bolt [J]. Chinese Journal of Rock Mechanics and Engineering, 2006, 25(9): 1876–1880. (in Chinese)

    Google Scholar 

  9. MUYA M S, HE B, WANG J T, LI G C. Effects of rock bolting on stress distribution around tunnel using the elastoplastic model [J]. Journal of Earth Science, 2006, 17(4): 337–341. DOI: https://doi.org/10.1016/S1002-0705(07)60008-9.

    Google Scholar 

  10. GOEL R K, ANIL S, SHEOREY P R. Bolt length requirement in underground openings [J]. International Journal of Rock Mechanics and Mining Sciences, 2007, 44(5): 802–811. DOI: https://doi.org/10.1016/j.ijrmms.2006.12.001.

    Article  Google Scholar 

  11. LIU H Y, SMALL J C, CARTER J P. Full 3D modelling for effects of tunnelling on existing support systems in the Sydney region [J]. Tunnelling and Underground Space Technology, 2007, 17(5): 569–572. DOI: https://doi.org/10.1016/j.tust.2007.06.009.

    Google Scholar 

  12. KILIC A, YASAR E, ATIS C D. Effect of bar shape on the pull out capacity of fully grouted rockbolts [J]. Tunneling and Underground Space Technology, 2003, 18(1): 1–6. DOI: https://doi.org/10.1016/S0886-7798(02)00077-9.

    Article  Google Scholar 

  13. KILIC A, YASAR E, CELIK A G. Effect of grout properties on the pull out load capacity of fully grouted rock bolt [J]. Tunneling and Underground Space Technology, 2002, 17(4): 355–362. DOI: https://doi.org/10.1016/S0886-7798(02)00038-X.

    Article  Google Scholar 

  14. BENMOKRANE B, CHENNOUF A, MITR H S. Laboratory evaluation of cement based grouts and grouted rock anchors [J]. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1995, 32(7): 633–642. DOI: https://doi.org/10.1016/0148-9062(95)00021-8.

    Article  Google Scholar 

  15. BENMOKRANE B, XUE X H, BELLAVANCE E. Bond strength of cement grouted glass fibre reinforce plastic (GFRP) anchor bolts [J]. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1996, 33(5): 455–465. DOI: https://doi.org/10.1016/0148-9062(96)00006-X.

    Article  Google Scholar 

  16. HOU Chao-jiong, GOU Pan-feng. Mechanism study on strength enhancement for the rocks surrounding roadway supported by rock [J]. Chinese Journal of Rock Mechanics and Engineering, 2000, 19(3): 342–345. (in Chinese)

    Google Scholar 

  17. YANG Shuang-suo, ZHANG Bai-sheng. The influence of bolt action force to the mechanical property of rocks [J]. Rock & Soil Mechanics, 2003, 24(S1): 279–282. (in Chinese)

    Google Scholar 

  18. SAWWAF M E, NAZIR A. The effect of soil reinforcement on pullout resistance of an existing vertical anchor plate in sand [J]. Computers and Geotechnics, 2006, 33(3): 167–176. DOI: https://doi.org/10.1016/j.compgeo.2006.04.001.

    Article  Google Scholar 

  19. ZOU Zhi-hui, WANG Zhi-lin. Mechanism of anchor bar in different elastic modulus rocks by model test [J]. Chinese Journal of Geotechnical Engineering, 1993, 16(5): 71–78. (in Chinese)

    Google Scholar 

  20. LIU Ai-qing, JU Wen-jun, HU Hai-tao, WANG Xiang. Experimental study on the effect of bolt prestress on the shear behavior of jointed rockmass [J]. Journal of China Coal Society, 2013, 38(3): 391–396. (in Chinese)

    Google Scholar 

  21. LU Li, ZHANG Si-ping, ZHANG Yong-xing, LIN Wei-xun. Configuration optimization of pressure-dispersive anchors in soft-hard interbed of sedimentary rock [J]. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(S2): 4124–4130. (in Chinese)

    Google Scholar 

  22. YANG Jian-hui, XIA Jian-zhong. Test study on the complete deformation property of bolted stratified surrounding rockmasses [J]. Journal of China Coal Society, 2005, 30(4): 414–417. (in Chinese)

    MathSciNet  Google Scholar 

  23. LI Xin-ping, WANG Tao, SONG Gui-hong, GUO Yun-hua, ZHANG Cheng-liang. Study on composite anchoring theory and numerical simulation test on layered rocks [J]. Chinese Journal of Rock Mechanics and Engineering, 2006, 25(S2): 3654–3660. (in Chinese)

    Google Scholar 

  24. CAO C, NEMCIK J, REN T, AZIZ N. A study of rock bolting failure modes [J]. International Journal of Mining Science and Technology, 2013, 23(1): 79–88. DOI: https://doi.org/10.1016/j.ijmst.2013.01.012.

    Article  Google Scholar 

  25. SONG H W, DUAN Y Y, YANG J. Numerical simulation on bolted rock joint shearing performance [J]. International Journal of Mining Science and Technology, 2010, 20(3): 460–465. DOI: https://doi.org/10.1016/S1674-5264(09)60226-X.

    Google Scholar 

  26. GHABRAIE B, GHABRAIE K, XIE Y M. A study on truss bolt mechanism in controlling stability of underground excavation and cutter roof failure [J]. Geotechnical and Geological Engineering, 2013, 31(2): 667–682. DOI: https://doi.org/10.1007/s10706-013-9617-7.

    Article  Google Scholar 

  27. JALALIFAR H, AZIZ N. Analytical behavior of bolt–joint intersection under lateral loading conditions [J]. Rock Mechanics and Rock Engineering, 2010, 43(1): 89–94. DOI: https://doi.org/10.1007/s00603-009-0032-6.

    Article  Google Scholar 

  28. KAMAL C D, DEBASIS D, JHA A K. An enhanced numerical procedure for modelling fully grouted bolts intersected by rock joint [J]. Geosystem Engineering, 2013, 16(1): 37–46. DOI:https://doi.org/10.1080/12269328.2013.780738.

    Article  Google Scholar 

  29. MARTIN L B, TIJANI M, HADJ-HASSEN F, NOIRET A. Assessment of the bolt-grout interface behavior of fully grouted rockbolts from laboratory experiments under axial loads [J]. International Journal of Rock Mechanics & Mining Sciences, 2013, 63: 50–61. DOI: https://doi.org/10.1016/j.ijrmms.2013.06.007.

    Article  Google Scholar 

  30. JALALIFAR H, AZIZ N, HADI M N S. Non-linear analysis of bolt-grout-concrete interaction in reinforced shear joint [J]. Journal of Mines, Metals and Fuels, 2004, 52(9): 208–216. https://doi.org/www.researchgate.net/publication/289400703_Non-linear_analysis_of_bolt-grout-concrete_Interaction_in_reinforced_shear_joint.

    Google Scholar 

  31. JALALIFAR H, AZIZ N. Numerical simulation of fully grouted rock bolts [M]// Numerical Simulation-From Theory to Industry, Dr. Mykhaylo Andriychuk (Ed), InTech, 2012: 607–640. DOI: https://doi.org/10.5772/48287.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Zeng-hui Zhao  (赵增辉).

Additional information

Foundation item: Projects(51774196, 41472280, 51578327) supported by the National Natural Science Foundation of China; Project(2016M592221) supported by the China Postdoctoral Science Foundation; Project(BJRC20160501) supported by the SDUST Young Teachers Teaching Talent Training Plan, China

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Zhao, Zh., Gao, Xj., Tan, Yl. et al. Theoretical and numerical study on reinforcing effect of rock-bolt through composite soft rock-mass. J. Cent. South Univ. 25, 2512–2522 (2018). https://doi.org/10.1007/s11771-018-3932-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11771-018-3932-3

Key words

关键词

Navigation