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http://dx.doi.org/10.14481/jkges.2014.15.1.53

The Stability Analysis of Near Parallel Tunnels Pillar at Multi-layered Soil with Shallow Depth by Numerical Analysis  

Lim, Hyungmin (Kyungpook National University, Department of Construction and Disaster prevention Engineering)
Son, Kwangrok (NANO-GEOtechnical E&C, R&D Institute)
Publication Information
Journal of the Korean GEO-environmental Society / v.15, no.1, 2014 , pp. 53-62 More about this Journal
Abstract
In Korea, in general, separation distance between existing parallel tunnels was set at two to five times as distant as the diameter of the tunnels according to ground conditions. Recently, however, actual applicability of closely spaced parallel tunnels whose distance between tunnel centers was shorter than the diameter has increased due to environmental damages resulting from massive cutting, restriction in purchase of required land, and maintenance of linear continuity. In particular, when the pillar width of tunnel decreases, the safety of pillars affects behaviors of the tunnel and therefore the need for diverse relevant studies has emerged. However, research so far has been largely confined to analysis of behavior characteristics of pillars, or parameters affecting design, and actually applicable and quantitative data have not been presented. Accordingly, in order to present a stability evaluation method which may maximally reflect construction conditions of spots, this study reflected topographical and stratigraphic characteristics of the portal part with the highest closeness between the tunnels, simulated multi-layer conditions with rock mass and complete weathering, and assessed the degree of effect the stability of pillars had on the entire tunnels through numerical analysis according to changes in pillar width by ground strength. This study also presented composite analysis result on ground surface settlement rates, interference volume rates, and average strength to stress and a formula, which may be applicable to actual work, to evaluate safety rates of closely spaced parallel tunnel pillars and minimum pillar width by ground strength based on failure criteria by Hoek-Brown (1980).
Keywords
Parallel tunnels; Pillar width; Interference volume ratio; Strength/stress ratio; Influence area;
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  • Reference
1 Adachi, T., Kimura, M. and Osada, T. (1993), Interaction between multitunnels under construction, Eleventh Southeast Asian Geotechnical Conference, Singapore, pp. 51-60.
2 Bieniawski, Z. T. (1976), Rock mass classification in rock engineering, in exploration for rock engineering, Proc. of the Symp., (ed. Z. T. Bieniawski) 1, Cape Town, Balkema, pp. 97-106.
3 Griffith, A. A. (1921), The phenomena of rupture and flow in solids, Phil. Trans. Royal Soc., London, Series A, Vol. 221, pp. 163-198.   DOI
4 Griffith, A. A. (1924), Theory of rupture, Proc. Int. Congress Appl. Mech., Delft, pp. 55-63.
5 Hoek, E. I. and Brown, E. T. (1980), Underground excavations in rock, The Institution of Mining and Metallurgy, London, pp. 87-227.
6 Im, S. B., Lee, S. M., Lee, J. W. and Paik, Y. S. (1994), Considerable parameters and progressive failure of rock masses due to the tunnel excavation, Journal of the Korean Geotechnical Society, Vol. 10, No. 3, pp. 231-234 (in Korean).
7 Jang, B. S. (2006), A study on the estimation of the behaviors of the pillar between twin tunnels, Ph D. dissertation, Hongik University, pp. 29-41 (in Korean).
8 Jang, S. B. and Moon, H. K. (1998), A study on the quantitative evaluation of the load distribution factors considering the design conditions of tunnel - especially for the ring-cut excavation method, Journal of the Korean Geotechnical Society, Vol. 14, No. 5, pp. 5-15 (in Korean).   과학기술학회마을
9 Kim, H. M. (1997), Effect of interference and ground movement by twin tunnelling, Journal of the Korean Society for Rock Mechanics, Vol. 7, No. 2, pp. 136-142 (in Korean).   과학기술학회마을
10 McClintock, F. A. and Walsh, J. B. (1962), Friction on Griffith cracks under pressure, Proc. 4th US National Congress Appl. Mech., New York, Vol. 2, pp. 1015-1021.
11 Obert, L. and Duvall, W. I. (1967), Rock mechanics and the design of structures in rock, John Wiley & Sons, New York, 650 p.
12 Peck, R. B. (1969), Deep excavations and tunnelling in soft grounding, State-of-the-Art Report, Proc. 7th International Conference Soil Mechanics and Foundation Engineering, Mexico, pp. 225-290.
13 Sterpi, D. and Cividini, A. (2004), A physical and numerical investigation on the stability of the shallow tunnels in strain softening media, Rock Mechanics and Rock Engineering, Vol. 37, No. 4, pp. 227-298.
14 Yoo, C. S., Lee, H. and Yoon, H. S. (1997), Three dimensional finite element analysis on twin tunnel behavior, Journal of the Korean Geotechnical Society, Vol. 13, No. 3, pp. 151-160 (in Korean).