Abstract
Rockbolts have been widely used in rock reinforcement for high-stress conditions in mining and civil engineering. However, the interaction mechanism between the rockbolt and the rock mass is still unclear. To fully understand the coupling mechanism of a rock mass supported with rockbolts, this article studied the coupling effect and the time-dependent behavior of a rock mass supported with continuously mechanically coupled (CMC) or continuously frictionally coupled (CFC) rockbolts. The elastic solutions of the interaction model were obtained in the coupled state. In addition, viscoelastic analytical solutions were used to describe the rheological properties of the coupling model, and the solutions were acquired by setting the constitutive models of the rockbolt and rock mass to a one-dimensional Kelvin model and a three-dimensional Maxwell model based on the material properties. According to the proposed coupling model, the rock mass stress and displacement fields, and the rockbolt axial force strongly depend on the relative deformation modulus of the rock mass and rockbolt. In addition, a lower viscosity coefficient of the rockbolt or rock mass produces a larger rock mass displacement. Moreover, as the relative deformation modulus increases, the distance to the neutral point beyond the rockbolt head increases. Furthermore, the position of the neutral point is independent of time.
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Abbreviations
- A b :
-
Cross-sectional area of the rockbolt
- K :
-
Bulk modulus of the rock mass
- ρ :
-
Radial coordinate
- r :
-
Tunnel radius
- d :
-
Rockbolt diameter
- σ 0 :
-
Initial rock mass stress
- \(u_{{\rho_{0} }}\) :
-
Rock mass displacement under the initial rock mass stress
- \(\varepsilon_{{\theta_{0} }}\) :
-
Rock mass tangential strain under the initial rock mass stress
- \(u_{{\rho_{2} }}^{\prime }\) :
-
Change of displacement in the unreinforced zone
- \(\varepsilon_{{\rho_{2} }}^{\prime }\) :
-
Change of radial strain in the unreinforced zone
- \(\sigma_{{\theta_{2} }}^{\prime }\) :
-
Change of tangential strain in the unreinforced zone
- \(\sigma_{{\rho_{1} }}\) :
-
Radial stress in the reinforced zone
- \(\sigma_{{\theta_{1} }}\) :
-
Tangential stress in the reinforced zone
- \(\varepsilon_{{\rho_{1} }}\) :
-
Radial strain in the reinforced zone
- \(\varepsilon_{{\theta_{1} }}\) :
-
Tangential strain in the reinforced zone
- \(u_{{\rho_{1} }}\) :
-
Rock mass displacement in the reinforced zone
- ε :
-
Axial strain of the rockbolt
- S θ :
-
Rockbolt spacing in the tangential direction
- t :
-
Time
- G r :
-
Shear modulus of the rock mass
- σ ij :
-
Stress tensor
- T N :
-
Axial force of the rockbolt in the neutral point
- T 1 :
-
Rockbolt axial force in front of the neutral point
- \(\overline{{P_{{{\text{a}}K}} }}^{\prime } (s), \, \overline{{Q_{{{\text{a}}K}} }}^{\prime } (s)\) :
-
Operator function of the rockbolt viscoelastic constitutive model after Laplace transformation
- τ a :
-
Additional shear stress beyond the neutral point
- \(\tau_{{{\text{B}}_{ 1} }}\) :
-
Shear stress before the neutral point
- p k, q k :
-
Constant parameters of the rockbolt material
- E r :
-
Deformation modulus of the rock mass
- E b :
-
Deformation modulus of the rockbolt
- Θ :
-
Angular coordinate
- R :
-
Radius of the reinforced zone
- L :
-
The length of the rockbolt
- μ r :
-
Poisson’s ratio of the rock mass
- \(\varepsilon_{{\rho_{0} }}\) :
-
Rock mass radial strain under the initial rock mass stress
- \(u_{{\rho_{1} }}^{\prime }\) :
-
Change of displacement in the reinforced zone
- \(\varepsilon_{{\rho_{1} }}^{\prime }\) :
-
Change of radial strain in the reinforced zone
- \(\varepsilon_{{\theta_{1} }}^{\prime }\) :
-
Change of tangential strain in the reinforced zone
- c :
-
Distance from the concentrated force to the rockbolt end
- \(\sigma_{{\rho_{2} }}\) :
-
Radial stress in the unreinforced zone
- \(\sigma_{{\theta_{2} }}\) :
-
Tangential stress in the unreinforced zone
- \(\varepsilon_{{\rho_{2} }}\) :
-
Radial strain in the unreinforced zone
- \(\varepsilon_{{\theta_{2} }}\) :
-
Tangential strain in the unreinforced zone
- \(u_{{\rho_{2} }}\) :
-
Radial displacement in the unreinforced zone
- \(\varepsilon_{{\rho_{0} }}\) :
-
Initial strain of the rock mass under the initial stress
- S z :
-
Rockbolt spacing in the longitudinal direction
- σ b :
-
Axial stress of the rockbolt
- u :
-
Displacement in the semi-infinite plane under the Mindlin solution
- ε ij :
-
Strain tensor
- ρ n :
-
The position of the neutral point
- T 2 :
-
Rockbolt axial force beyond the neutral point
- \(\begin{aligned} \overline{P}^{\prime } (s),\;\;\overline{Q}^{\prime } (s) \hfill \\ \overline{P}^{\prime \prime } (s),\;\;\overline{Q}^{\prime \prime } (s) \hfill \\ \end{aligned}\) :
-
Operator function of the rock mass viscoelastic constitutive model after Laplace transformation
- τ b :
-
Shear stress caused by the rock mass deformation
- \(\tau_{{{\text{B}}_{ 2} }}\) :
-
Shear stress beyond the neutral point
- D :
-
Differential operator
References
Bjornfot F, Stephansson O (1984) Interaction of grouted rock bolts and hard rock masses at variable loading in a test drift of the Kiirunavaara Mine, Sweden. In: Stephansson P (ed) Proceedings of the International Symposium on rock bolting. Rotterdam, Balkema, pp 377–395
Cai Y, Esakia Tetsuro, Jiang YJ (2004) Arock bolt and rock mass interaction model. Int J Rock Mech Min Sci 41(2004):1055–1067
Cai Y, Jiang YJ, Djamaluddin I et al (2015) An analytical model considering interaction behavior of grouted rock bolts for convergence–confinement method in tunneling design. Int J Rock Mech Min Sci 76:112–126
Chen J, Hagan PC, Saydam S (2016) Parametric study on the axial performance of a fully grouted cable bolt with a new pull-out test. Int J Min Sci Technol 26:53–58
Chen Y, Li CC (2015) Performance of fully encapsulated rebar bolts and D-bolts under combined pull-and-shear loading. Tunn Undergr Space Technol 45:99–106
Freeman TJ (1978) The behavior of fully-bonded rock bolts in the Kielder experimental tunnel. Tunnels Tunnel 1978:37–40
Ghaboussi J, Gioda G (1977) On the time-dependent effects in advancing tunnels. Int J Numer Methods Geomech 2:249–269
Goodman R (1989) Introduction to rock mechanics, 2nd edn. Wiley, New York
Han W, Wang G, Liu CZ et al (2018) Time-dependent behavior of a circular symmetrical tunnel supported with rockbolts. Symmetry-Basel 6(9):381
Huang JB, Cen S, Shang Y et al (2017) A new triangular hybrid displacement function element for static and free vibration analyses of Mindlin-Reissner Plate. Latin Am J Solids Struct 14(5):765–804
Kovári K (2003) History of the sprayed concrete lining method—part I. Milestones up to the 1960s. Tunn Undergr Space Technol 18:57–69
Ladanyi B (1993) Time dependent response of rock around tunnel. In: Hudson J (ed) Comprehensive rock engineering, vol 2. Pergamon Press, Oxford, pp 77–112
Ladanyi B, Gill D (1984) Tunnel lining design in creeping rocks. In: symposium on design and performance of underground excavations. ISRM, Cambridge
Li C, Stillborg B (1999) Analytical models for rock bolts. Int J Rock Mech Min Sci 36:1013–1029
Ma S, Nemcik J, Aziz N (2013) An analytical model of fully grouted rock bolts subjected to tensile load. Constr Build Mater 49:519–526
Mindlin RD (1953) Force at a point in the interior of a semi-infinite solid. In: British Columbia Univvancouver Dept of Civil Engineering
Nomikos P, Rahmannejad R, Sofianos A (2011) Supported axisymmetric tunnels within linear viscoelastic Burgers rocks. Rock Mech Rock Eng 44(5):553–564
Panet M (1993) Understanding deformations in tunnels. In: Hudson J (ed) Comprehensive rock engineering, vol 1. Pergamon Press, Oxford, pp 663–690
Peila D, Oreste P, Rabajuli G, Trabucco E (1995) The pre-tunnel method, a new Italian technology for full-face tunnel excavation: a numerical approach to design. Tunnel Undergr Space Technol 10:3
Phillips SHE (1970) Factors affecting the design of anchorages in rock [R], London: cementation Research Ltd
Stillborg B (1994) Professional users handbook for rock bolting, 2nd edn. Trans Tech Publications, Clausthal-Zeuerfeld, pp 30–42
Sulem J, Panet M, Guenot A (1987) An analytical solution for time-dependent displacements in circular tunnel. Int J Rock Mech Min Sci Geomech Abstr 24(3):155–164
Sun J (2007) Rock rheological mechanics and its advance in engineering applications. Chin J Rock Mech Eng 26(6):1081–1106
Tao Z, Chen JX (1984) Behavior of rock bolting as tunneling support. In: Stephansson O (ed) Proceedings of the international symposium on rock bolting. Balkema, Rotterdam, pp 87–92
Teymen A, Kılıç A (2018) Effect of grout strength on the stress distribution (tensile) of fully-grouted rockbolts. Tunn Undergr Space Technol 77:280–287
Wang ZY, Li YP (2008) Rock rheology theory and numerical simulation. Science Press, Beijing (in Chinese)
Wang G, Liu CZ, Jiang YJ et al (2015) Rheological model of DMFC Rockbolt and Rockmass in a circular tunnel. Rock Mech Rock Eng 48:2319–2357
Wang G, Liu CZ, Wu XZ (2014) Coupling rheological model for end-anchored bolt and surrounding rock mass. Chin J Geotech Eng 36(2):363–375
Windsor CR, Thompson AG (1993) Rock reinforcement—technology, testing, design and evaluation. In: Hudson JA (ed) Comprehensive rock engineering, principles, practice & projects, vol 4. Pergamon Press, Oxford, pp 451–484
Wu XZ, Jiang YJ, Guan ZC, Wang G (2018) Estimating the support effect of the energy-absorbing rock bolt based on the mechanical work transfer ability. Int J Rock Mech Min Sci 103:168–178
Yao XC, Li N, Chen YS (2005) Theoretical solution for shear stresses on interface of fully grouted bolt in tunnels. Chin J Rock Mech Eng 24(13):2272–2276
Acknowledgements
This study was supported by the National Natural Science Foundation of China (no. 51479108) and the Taishan Scholar Talent Team Support Plan for Advantaged & Unique Discipline Areas.
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Appendix
Appendix
The elastic solutions in the reinforced zone of the rock mass supported with CFC or CMC rockbolts are shown below.
The radial stress can be expressed as
The tangential stress can be written as
The radial strain can be expressed as
The tangential strain can be expressed as
The displacement can be written as
The values of the parameters A, C1, C2 and C3 in 45–49 are given below:
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Wang, G., Han, W., Jiang, Y. et al. Coupling Analysis for Rock Mass Supported with CMC or CFC Rockbolts Based on Viscoelastic Method. Rock Mech Rock Eng 52, 4565–4588 (2019). https://doi.org/10.1007/s00603-019-01840-6
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DOI: https://doi.org/10.1007/s00603-019-01840-6