Abstract
In this paper, finite element limit analysis (FELA) and semi-analytical rigid block techniques are used to investigate the influence of tunnel spacing on the undrained stability of two unlined square tunnels constructed side by side. The tunnels, which are assumed to be straight and infinitely long, are modelled under conditions of plane strain. Upper and lower bounds on the stability of the tunnels are obtained using FELA; the numerical formulation of which is based upon the bounds theorems of classical plasticity. These bounds, which bracket the true collapse load from above and below, are found to be in good agreement with one another. Rigid block methods also provided an upper bound estimate on tunnel stability which was generally higher than, but still in good agreement with, the FELA upper bound. Failure mechanisms associated with the collapse of the dual tunnels were investigated, and for deeper tunnels, it was found that mechanisms extend much deeper below the tunnels than the collapse mechanisms associated with a single tunnel. Results from this study are summarised in dimensionless stability charts for use by practitioners.
Similar content being viewed by others
References
Abbo AJ, Wilson DW, Sloan SW, Lyamin AV (2013) Undrained stability of wide rectangular tunnels. Accepted for publication in Computers and Geotechnics, April 2013
Ahmed M, Iskander M (2011) Analysis of tunneling-induced ground movements using transparent soil models. J Geotech Geoenv Eng ASCE 137(5):525–535
Assadi A, Sloan SW (1991) Undrained stability of a shallow square tunnel. J Geotech Division ASCE 117:1152–1173
Atkinson JM, Cairncross AM (1973) Collapse of a shallow tunnel in a Mohr-Coulomb material. In: Palmer AC (ed), Role of plasticity in soil mechanics: 202–206. Proceedings of Symposium, Cambridge, Sept 13–15
Augarde CE, Lyamin AV, Sloan SW (2003) Stability of an undrained plane strain heading revisited. Comput Geotech 30:419–430
Chen WF (1975) Limit analysis and soil plasticity. Elsevier Scientific Publishing Company, Amsterdam
Davis EH, Gunn MJ, Mair RJ, Seneviratne HN (1980) The stability of shallow tunnels and underground openings in cohesive material. Geotechnique 30:397–416
Ghaboussi J, Ranken RE (1977) Interaction between two parallel tunnels. Int J Numer Analyt Meth Geomech 1:75–103
Hooke R, Jeeves TA (1961) Direct search solution of numerical and statistical problems. J Assoc Comput Mach 8(2):212–229
Klar A, Osman AS, Bolton M (2007) 2D and 3D upper bound solutions for tunnel excavation using elastic flow fields. Int J Numer Analyt Meth Geomech 31:1367–1374
Krabbenhoft K, Lyamin AV, Hjiaj M, Sloan SW (2005) A new discontinuous upper bound limit analysis formulation. Int J Numer Meth Eng 63:1069–1088
Krabbenhoft K, Lyamin AV, Sloan SW (2007) Formulation and solution of some plasticity problems as conic programs. Int J Solids Struct 44:1533–1549
Leca E, Dormieux L (1990) Upper and lower bound solutions for the face stability of shallow circular tunnels in frictional material. Géotechnique 40(4):581–606
Lee CJ, Wu BR, Chen HT, Chiang KH (2006) Tunnel stability and arching effects during tunneling in soft clayey soil. Tunn Undergr Space Technol 21:119–132
Lyamin AV, Sloan SW (2002) Lower bound limit analysis using nonlinear programming. Int J Numer Meth Eng 55:573–611
Lyamin AV, Sloan SW (2002) Upper bound limit analysis using linear finite elements and nonlinear programming. Int J Numer Anal Meth Geomech 26(2):181–216
Lyamin AV, Jack D, Sloan SW (2001) Collapse analysis of square tunnels in cohesive-frictional soils. In: First Asian-Pacific Congress on Computational Mechanics (APCOM 01), Sydney, Australia, 405–414
Mair RJ (1979) Centrifugal modelling of tunnel construction in soft clay. PhD Thesis, University of Cambridge
Muhlhaus HB (1985) Lower bound solutions for circular tunnels in two and three dimensions. Rock Mech Rock Eng 18:37–52
Osman AS (2010) Stability of unlined twin tunnels in undrained clay. Tunn Undergr Space Technol 25:290–296
Osman AS, Mair RJ, Bolton MD (2006) On the kinematics of 2D tunnel collapse in undrained clay. Geotechnique 56(9):585–595
Sloan SW (1988) Lower bound limit analysis using finite elements and linear programming. Int J Numer Anal Meth Geomech 12:61–67
Sloan SW (1989) Upper bound limit analysis using finite elements and linear programming. Int J Numer Anal Meth Geomech 13:263–282
Sloan SW, Assadi A (1991) Undrained stability of a square tunnel in a soil whose strength increases linearly with depth. Comput Geotech 12:321–346
Sloan SW, Assadi A (1992) The stability of tunnels in soft ground. In: Proceedings of Peter Wroth memorial symposium on predictive soil mechanics, Oxford, 644–663
Sloan SW, Assadi A (1994) Undrained stability of a plane strain heading. Can Geotech J 31(3):443–450
Suwansawat S, Einstein H (2007) Describing settlement troughs over twin tunnels using a superposition technique. J Geotech Geoenv Eng ASCE 133(4):445–468
Wilson DW, Abbo AJ, Sloan SW, Lyamin AV (2008) Undrained stability of dual square tunnels. In: 12th International conference of the international association for computer methods and advances in geomechanics, Goa, India, 4284–4291
Wilson DW, Abbo AJ, Sloan SW, Lyamin AV (2011) Undrained stability of a circular tunnel where the shear strength increases linearly with depth. Can Geotech J 48:1328–1342
Wilson DW, Abbo AJ, Sloan SW, Lyamin AV (2013) Undrained stability of dual circular tunnels. Accepted for Publ Int J Geomech, Jan 2013
Wu BR, Lee CJ (2003) Ground movements and collapse mechanisms induced by tunneling in clayey soil. Int J Phys Model Geotech 3(4):13–27
Xie J, Gunn MJ, Rahim A (2004) Collapse analysis for two parallel circular tunnels with difference diameters in soil. Numer Models Geomech IX:421–426
Yamamoto K, Lyamin AV, Sloan SW, Abbo AJ (2006) Limit analysis of shallow tunnels in cohesive frictional soils. J Appl Mech JSCE 9:395–406 (in Japanese)
Yamamoto K, Lyamin AV, Sloan SW, Abbo AJ (2008) Bearing capacity of cohesive frictional soils with shallow tunnels of different cross section. J Struct Eng JSCE 54A:918–927 (in Japanese)
Yamamoto K, Lyamin AV, Wilson DW, Sloan SW, Abbo AJ (2011) Stability of a circular tunnel in cohesive-frictional soil subjected to surcharge loading. Comput Geotech 38:504–514
Yamamoto K, Lyamin AV, Wilson DW, Sloan SW, Abbo AJ (2011) Stability of a single tunnel in cohesive–frictional soil subjected to surcharge loading. Can Geotech J 48:1841–1854
Yamamoto K, Lyamin AV, Wilson DW, Sloan SW, Abbo AJ (2013) Stability of dual circular tunnels in cohesive-frictional soil subjected to surcharge loading. Comput Geotech 50:41–54
Yang F, Yang JS (2010) Stability of shallow tunnel using rigid blocks and finite-element upper bound solutions. Int J Geomech ASCE 10:242–247
Acknowledgments
The research reported in this paper was made possible by the Australian Laureate Fellowship Grant FL0992039 awarded to Professor Scott Sloan by the Australian Research Council. The Authors are grateful for this support.
Author information
Authors and Affiliations
Corresponding author
Appendix 1
Appendix 1
Table 1 in this appendix gives the values used to generate the stability charts in Figs. 6, 7, 8, 9, 10 and 11. The superscripts identify the rigid block failure mechanism that provided the minimum rigid block solution. Rigid block solutions governed by a dual tunnel collapse modes are annotated with a numeral that specifies the critical rigid block mechanism as shown in Fig. 4. Solutions governed by single tunnel collapse modes are annotated with a letter that refers to a mechanism shown in Fig. 5.
Rights and permissions
About this article
Cite this article
Wilson, D.W., Abbo, A.J., Sloan, S.W. et al. Undrained stability of dual square tunnels. Acta Geotech. 10, 665–682 (2015). https://doi.org/10.1007/s11440-014-0340-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11440-014-0340-1