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http://dx.doi.org/10.7843/kgs.2017.33.3.29

3D Numerical Study on the Reinforcing Effect of Inclined System Bolting in NATM Tunnel  

Heo, June (Geotechnical and Tunnelling Dept. Kyongdong Eng.)
Kim, Byoung-Il (Dept. of Civil & Environmental Engrg., Myongji Univ.)
Lee, Jea-Dug (Geotechnical Engrg. Research Institute)
Kim, Young-Geun (Geotechnical and Tunnelling Dept. Kunhwa Eng.)
Publication Information
Journal of the Korean Geotechnical Society / v.33, no.3, 2017 , pp. 29-36 More about this Journal
Abstract
It has been known that rockbolt is one of important supports improving the support capacity with shotcrete in NATM tunnel. Also, it is necessary for the inclined system bolting to enhance the efficiency of installation in case of a narrow space such as cross passage and enlargement tunnel. However, there is no profound technical study for the effect of inclined rockbolt of systematic installation on the support mechanism and ground behaviour in NATM tunnel. In this study, the effects of the length and installation angle of rockbolt on the characteristics of support and ground reinforcement were analyzed by using 3D finite element numerical study. Through the numerical results for the parametric modelling of inclined rockbolt, the characteristics of mechanical behaviors between the axial force of rockbolt and the effect of ground reinforcement in regard to the various factors of the length and installation angle of rockbolt were verified and reviewed thoroughly. Also, it was shown that the installation angle of rockbolt for enhancing the arching effect in NATM tunnel was $45^{\circ}$, and the difference of the reinforcing effect for support between the installation angles of $75^{\circ}$ and $90^{\circ}$ was insignificant. The additional numerical studies for various condition would be carried out for practical design guideline of inclined rockbolt.
Keywords
3D Numerical analysis; Inclined rockbolt; Reinforcement effect; NATM tunnel;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
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1 Hyett, A.J., Moosavi, M., and Bawden, W.F. (1996), "Load Distribution along Fully Grouted Bolts, with Emphasis on Cable Bolt Reinforcement", Int. J. Numer. & Anal. Meth. Geomech, Vol.20, pp.517-544.   DOI
2 Kim, U.G., Baek, K.H., Seo, K.W., Kim, D.K., and Woo, S.B. (2010), "Numerical Study on Effect of Ground Reinforcement with Installation Angle of Rockbolt", Korean Society for Rock Mechanics Conference, pp.199-204.
3 KSGE (1997), "Geotechnical Engineering Series-7th", Goomi Publisher, p.663.
4 Lee, J.D. (2012), "Effect of Installation Angle on Ground Reinforcement in System Bolting", Ph.D. Dissertation, Myongji University, pp.1-119.
5 Lee, S.D. (2013), "Tunnel Mechanics", CIR Publisher, pp.387-480.
6 Lee, Y.K., Song, W.K., Park, C.W., and Choi, B.H. (2010), "Numerical Study on the Behavior of Fully Grouted Rock Bolts with Different Boundary Conditions", Journal of Korean Society for Rock Mechanics, Vol.20, No.4 pp.267-276.
7 Talobre, J. (1957), "La Mechanique des Roches : Appliquee aux travaux publics", Dunod.
8 Baek, K.H. (2011), "Ground Behavior Analysis and Protector Design during the Enlargement of a Tunnel in Operation", Inha University, pp.1-3.
9 MLTMA (2010), "The Revision of the Road-Design Guideline-6th Tunnel", Ministry of Land, Transport and Maritime Affairs, pp. 605.2-606.4.
10 Freeman, T.J. (1978), "The Behaviour of Fully-bonded Rock Bolts in Kielder Experimental Tunnel", Tunnel & Tunnelling, pp.37-40.
11 Heo, J. (2016), "A 3D Numerical Analysis on the Reinforcing Effect of Inclined System Bolting", Master Dissertation, Myongji University, pp.13-25.