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Stability of rectangular tunnel in improved soil surrounded by soft clay

  • Siddharth Pandey (Department of Civil Engineering, Indian Institute of Technology Roorkee) ;
  • Akanksha Tyagi (Department of Civil Engineering, Indian Institute of Technology Roorkee)
  • Received : 2022.07.26
  • Accepted : 2023.07.24
  • Published : 2023.09.10

Abstract

The practical usage of underground space and demand for vehicular tunnels necessitate the construction of non-circular wide rectangular tunnels. However, constructing large tunnels in soft clayey soil conditions with no ground improvement can lead to excessive ground deformations and collapse. In recent years, in situ ground improvement techniques such as jet grouting and deep cement mixing are often utilized to perform cement-stabilisation around the tunnel boundary to prevent large deformations and failure. This paper discusses the stability characteristics and failure behaviour of a wide rectangular tunnel in cement-treated soft clays. First, the plane strain finite element model is developed and validated with the results of centrifuge model tests available in the past literature. The critical tunnel support pressures computed from the numerical study are found to be in good agreement with those of centrifuge model tests. The influence of varying strength and thickness of improved soil surround, and cover depth are studied on the stability and failure modes of a rectangular tunnel. It is observed that the failure behaviour of the tunnel in improved soil surround depends on the ratio of the strength of improved soil surround to the strength of surrounding soil, i.e., qui/qus, rather than just qui. For low qui/qus ratios,the stability increases with the cover; however, for the high strength improved soil surrounds with qui >> qus, the stability decreases with the cover. The failure chart, modified stability equation, and stability chart are also proposed as preliminary design guidelines for constructing rectangular tunnels in the improved soil surrounded by soft clays.

Keywords

Acknowledgement

The authors would like to thank the Ministry of Education, Govt. of India, for providing financial assistance to the first author during his M.Tech. program.

References

  1. Abbo, A.J., Wilson, D.W., Sloan, S.W. and Lyamin, A.V. (2013), "Undrained stability of wide rectangular tunnel", J. Comput. Geotech., 53, 46-59. https://dx.doi.org/10.1016/j.compgeo.2013.04.005.
  2. Arroyo, M., Gens, A., Croce, P. and Modoni, A. (2011), "Design of jet-grouting for tunnel waterproofing", Proceedings of 7th International Symposium on Geotechnical Aspects of Underground Construction in Soft Ground, Rome, Italy, May.
  3. Assadi. A. and Sloan, S.W. (1991), "Undrained stability of shallow square tunnel", J. Geotech. Eng., 117(8), 1152-1173. https://doi.org/10.1061/(ASCE)0733-9410(1991)117:8(1152)
  4. Broms, B.B. (2004), "Lime and lime/cement columns", Ground improvement, 2, (Eds., M.P. Moseley and K. Kirsch), Taylor & Francis, London.
  5. Broms, B.B. and Bennemark, H. (1967), "Stability of clay at vertical openings", J. Soil Mech Found. Division, 193(1), 71-94. https://doi.org/10.1061/JSFEAQ.0000946.
  6. Casarin, C. and Mair, R.J. (1981), "The assessment of tunnel stability in clay by model tests", Soft ground tunnelling, failures and displacements, (Eds., D. Resendiz and M. Romo), A.A. Balkema, Rotterdam, Netherlands.
  7. Caudle, R.D. and Clark, G.B. (1955), "Stress around mine openings in some geological structures", University of Illinois Bulletin, 52(69), 7-37.
  8. Chen, X., Ma, B., Najafi, M. and Zhang, P. (2019), "Long rectangular box jacketing Project: A Case study", Undergr. Space, 6(2) 101-125. https://doi.org/10.1016/j.undsp.2019.08.003
  9. Chin, K.G. (2006). "Constitutive behaviour of cement treated marine clay", Ph.D. Thesis. National University of Singapore, Singapore.
  10. Conitin A., Cividini, A. and Gioda, G (2007), "Numerical evaluation of surface displacement of due to soil grouting and to tunnel excavation", Int. J. Geomech., 7(3), 217-226. https://doi.org/10.1061/(ASCE)1532-3641(2007)7:3(217).
  11. Croce, P., Flora A. and Modoni, G. (2014), Jet Grouting: Technology, Design and Control, Taylor and Francis, London, New York.
  12. Davis, E.N., Gunn, M.J., Mair, R.J. and Seneviratne, H.N. (1980), "The stability of shallow tunnels and underground openings in cohesive material", Geotechnique, 30(4), 397-416. https://doi.org/10.1680/geot.1980.30.4.397.
  13. Dutta, P. and Bhattacharya, P. (2019), "Stability of rectangular tunnels in cohesion less soil", Int. J. Geotech. Eng., 15(10), 1345-1351. https://doi.org/10.1080/19386362.2019.1592874.
  14. Fuente, M., Sulem, J., Taherzadeh, R. and Subrin D, (2019), "Tunneling in Squeezing ground: Effect of the excavation method", Rock Mech. Rock Eng., 53 601-623. https://doi.org/10.1007/s00603-019-01931-4.
  15. Ganeshan, V. and Yang, J.Y. (2009), "Jet grouting and its application", Proceedings of International Symposium on Ground improvement Technologies and Case Histories, Singapore, December.
  16. Gavin, K., Wout, B., Kovacevic, M.S. and Dehass, K. (2019), "Investigation of remaining life of an immersed tunnel in Netherland", Proceedings in Tunnels and Underground Cities: Engineering and Innovation Meet Archaeology and Art Taylor and Francis, London, 4831-4838. http://doi.org/10.1201/9780429424441-512.
  17. Khezri, N., Mohamad, H. and Fatahi, B. (2016), "Stability assessment of tunnel face in a layered soil using upper bound theorem of limit analysis", Geomech. Eng., 11(4), 471-492. http://doi.org/10.12989/gae.2016.11.4.471.
  18. Kimura, T. and Mair, R.J. (1981), "Centrifuge testing of model tunnels in soft clay", Proceedings of 10th International Conference of Soil Mechanics and Foundation Engineering, Rotterdam, Netherlands.
  19. Kitazume, M. and Terashi, M. (2013), The Deep Mixing Method, Taylor & Francis, London.
  20. Lee, C.J., Wu, B.R., Chen, H.T. and Chiang, K.H. (2006), "Tunnel stability and arching effects during tunneling in soft clayey soil", Tunn. Undergr. Sp. Tech., 21(2), 119-132. https://doi.org/10.1080/19386362.2019.1592874.
  21. Liu, W., Wu, Y., Zhao H., Xu., X. and Miao, L. (2021), "Deformation of subway tunnel induced by overcrossing jacked box tunnel", Symmetry Journals 13 1-15. https://doi.org/10.3390/sym13101800
  22. Lyamin, A.V., Jack, D.L. and Sloan, S.W. (2001), "Collapse analysis of square tunnels in cohesive-frictional soils", Proceedings of the First Asian-Pacific Congress on Computational Mechanics, Sydney, N.S.W., Australia, November.
  23. Mair, R.J. (1979), "Centrifugal modelling of tunnel construction in soft clay", Ph.D. Thesis, University of Cambridge, Cambridge, U.K.
  24. Pan, Y.T., Xiao, H.W., Lee, F.H. and Phoon, K.K. (2016), "Modified isotropic compression relationship for cement-admixed marine clay at low confining stress", Geotech. Test. J., 39(4), 695-702. https://doi:10.1520/GTJ20150147.
  25. Pan, Y., Liu, Y., Tyagi, A., Lee, F.H. and Li, D.Q. (2020), "Model Independent strength reduction factor for effect of spatial variability on tunnels with improved soil surround", Geotechnique, 71(5), 406-422. https://doi.org/10.1680/jgeot.19.P.056.
  26. Pellegrino, G. and Adams, D.N. (1996), "The use of jet grouting to improve soft clays for open face tunnelling", Proceedings of the 2nd Symposium on Geotechnical aspects of Underground Construction in Soft Ground, Rotterdam, Netherlands.
  27. Pellegrino, G. and Bruce, D.A. (1996), "Jet grouting for the solution of tunnelling problems in soft clays", Grouting and deep mixing, Netherlands.
  28. Pham, V.V., Do, N.A. and Dias, D. (2021), "Sub rectangular tunnel behaviour under seismic loading", Appl. Sciences, 11(21), 9909. https://doi.org/10.3390/app11219909.
  29. Plaxis 2D Ultimate (Computer software), Bentley Systems.
  30. Qui, J., Liu, H., Lai, H., Chen, J. and Wang, K. (2018), "Investigating long term settlement of a tunnel built over improved loessial foundation soil using jet grouting technique", J. Perform. Constr. Fac., 04018066 1-15. https://doi.org/10.1061/(ASCE)CF.1943-5509.0001155.
  31. Raju, V.R., Yohannes, M.M and Daramalinggam (2021), "The development of deep soil mixing practice and application in Malaysia", Proceedings of the Deep foundation Institute Deep Soil Mixing - Online Conference 2021.
  32. Sloan, S.W. and Assadi, A. (1991), "Undrained stability of square tunnel in soil whose strength increases linearly with depth", Comput. Geotech., 12, 321-346. https://doi.org/10.1016/0266-352X(91)90028-E.
  33. Tan, T.S., Goh, T.L. and Yong, K.Y. (2002), "Properties of Singapore marine clays improved by cement mixing", Geotech. Test. J., 25(4), 422-433. https://doi.org 10.1520/GTJ11295J.
  34. Terashi, M., Tanaka, H., Mitsumoto, T., Niidome, Y. and Honma, S. (1980), "Fundamental properties of lime and cement-treated soils", Rep. PHRI, 19(1), 33-62 (in Japanese).
  35. Terashi, M. and Tanaka, H. (1983), "Settlement analysis for deep mixing method", Proceedings of the 8 th European Conference on SMFE, Vol. 2, A.A. Balkema, Rotterdam, Netherlands.
  36. Tornaghi, R. and Cippo, A.P. (1985), Soil Improvement by Jet Grouting for the Solution of Tunnelling Problems, Institution of Mining ang metallurgy, London, United Kingdom.
  37. Tyagi, A., Zulkefli, M.F.B., Pan Y., Goh, S.H. and Lee, F.H. (2017), "Failure modes of tunnel with improved soil surround", J. Geotech. Geoenviron. Eng., 143(11), 04017088, 1-13. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001788.
  38. Tyagi, A. and Lee, F. H (2017), "Factors affecting stability of large diameter tunnel in improved soil surround", Proceedings of 19th International Conference on Soil mechanics and Geotechnical Engineering Seoul, South Korea, September
  39. Tyagi, A., Liu, Y., Pan, Y.T., Ridhwan, K.B.M. and Lee, F.H. (2018), "Stability of tunnels in cement-admixed soft soils with spatial variability", ASCE J. Geotech. Geoenviron. Eng., 06018012, 1-7. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001988.
  40. Tyagi, A., Wong, Y.C. and Lee, F.H (2019), "Effect of loading strain rates on peak strength and drainage behaviour of cement-treated clay", Proceedings of the 16th Asian regional Conference on Soil Mechanics and Geotechnical Engineering, Taipei, Taiwan, October.
  41. Tyagi A., Liu Y., Pan Y.T. and Lee F.H. (2020), "Equivalent strength for tunnels in cement-admixed soil columns with spatial variability and positioning error", ASCE J. Geotech. Geoenviron. Eng., 146(10), 04020101, 1-13. https://doi.org/10.1061/(ASCE)GT.1943-5606.0002351.
  42. Tyagi, A. and Lee, F.H. (2022), "Influence of tunnel failure on the existing large diameter tunnel in improved soil surround", Tunn. Undergr. Sp. Tech., 120, 104247, 1-19. https://doi.org/10.1016/j.tust.2021.104276.
  43. Tyagi, A. and Tamta, D. (2023), "Equivalent design strengths for spatially variable cement-treated soil slope", Int. J. Geomech. ASCE, article in production. https://doi.org/10.1061/IJGNAI/GMENG-8207.
  44. Uktitchon, B. and Keawsawasvong, S. (2020), "Undrained stability of unlined square tunnel in clays with linearly increasing anisotropic shear strength", Geotech. Geol. Eng., 38, 897-915. https://doi.org/10.1007/s10706-019-01023-8.
  45. Wang, Y.Q., Kong, W.K. and Wang, Z.F. (2018), "Effect of expanding rectangular tunnels on adjacent structures", Adv. Civil Eng., 1729041. https://doi.org/10.1155/2018/1729041.
  46. Wang, L., Kong, C., Peng, F., Zhang, B., Deng, J., Gu, S. and Sun, Q. (2020), "Construction of large-section long pedestrian underpass using pipe jacking in water filled clay", Proceedings of the International conference on road tunnel safety and risk prevention and control, Chongqing, China, December.
  47. Wilson, D.W., Abbo, A.J., Sloan, S.W. and Yamamoto, K. (2017), "Undrained stability of rectangular tunnels where shear strength increases linearly with depth", Can. Geotech. J., 54(4), 469-480. https://doi.org/10.1139/cgj-2016-0072.
  48. Xiao, H.W. (2009), "Yielding and failure of cement treated soil", Ph.D. Thesis, National University of Singapore, Singapore.
  49. Yamamoto, K., Lyamin, A.V., Wilson, D.W., Sloan, S.W. and Abbo, A.J. (2011), "Stability of a circular tunnel in cohesive frictional soil subjected to surcharge loading", Comput. Geotech., 38(4), 504-514. https://doi.org/10.1016/j.compgeo.2011.02.014.
  50. Yang, F. and Yang J.S. (2010), "Stability of shallow tunnel using rigid blocks and finite element upper bound solutions", Int. J. Geomech., 10(6), 242-247. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000011.
  51. Yang, X.L. and Qin, C.B. (2014), "Limit analysis of rectangular cavity subjected to seepage forces based on Hoek-Brown failure criteria", Geomech. Eng., 6(5) 503-515. https://doi.org/10.12989/gae.2014.6.5.503.
  52. Yang, X.L. and Zhang, R. (2017), "Collapse analysis of shallow tunnel subjected to seepage in layered soil considering joined effect of settlement and dilation", Geomech. Eng., 13(2), 217-235. https://doi.org/10.12989/gae.2017.13.2.217.
  53. Yee, Y.W. and Tan, Y.C. (2015), "Excavation support for TBM retrieval shaft using deep soil mixing technique, Kuala Lumpur", Proceedings of the International conference and exhibition on Tunneling and underground space. Institute of Engineers Malaysia (IEM) Malaysia.
  54. Zhang, J., Hang, Z., Feng, T. and Yang, F. (2020), "Assessment of the stability of an unlined rectangular tunnel with an overload on the ground surface", Adv. Civil Eng., 6616067, 1-13. https://doi.org/10.1155/2020/6616067.
  55. Zhao. H., Sun, H., Zhang, D. and Liu, C. (2021), "Mechanical properties of progressive failure characteristics of sandstone containing elliptical and square openings subjected to biaxial stress", Plos One 16(3), 1-22. https://doi.org/10.1371/journal.pone.0246815.
  56. Zulkefli, M.F.B., Tyagi, A. and Lee, F.H. (2017), "Collapse behaviour of large rectangular tunnel in improved soil surround", Proceedings of the 9th International Symposium on Geotechnical Aspects of underground Construction in Soft Grounds (IS-Sao Paulo 2017), (Eds., A. Negro and M.O. Cecilio Jr.), CRC Press/Balkema, The Netherlands, April.