Geomechanics and Engineering

Techno-Press (테크노프레스)
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Numerical evaluation of surface settlement induced by ground loss from the face and annular gap of EPB shield tunneling

  • An, Jun-Beom (Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology) ;
  • Kang, Seok-Jun (Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology) ;
  • Kim, Jin (Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology) ;
  • Cho, Gye-Chun (Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology)
  • Received : 2021.12.17
  • Accepted : 2022.03.09
  • Published : 2022.05.10
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Abstract

Tunnel boring machines combined with the earth pressure balanced shield method (EPB shield TBMs) have been adopted in urban areas as they allow excavation of tunnels with limited ground deformation through continuous and repetitive excavation and support. Nevertheless, the expansion of TBM construction requires much more minor and exquisitely controlled surface settlement to prevent economic loss. Several parametric studies controlling the tunnel's geometry, ground properties, and TBM operational factors assuming ordinary conditions for EPB shield TBM excavation have been conducted, but the impact of excessive excavation on the induced settlement has not been adequately studied. This study conducted a numerical evaluation of surface settlement induced by the ground loss from face imbalance, excessive excavation, and tail void grouting. The numerical model was constructed using FLAC3D and validated by comparing its result with the field data from literature. Then, parametric studies were conducted by controlling the ground stiffness, face pressure, tail void grouting pressure, and additional volume of muck discharge. As a result, the contribution of these operational factors to the surface settlement appeared differently depending on the ground stiffness. Except for the ground stiffness as the dominant factor, the order of variation of surface settlement was investigated, and the volume of additional muck discharge was found to be the largest, followed by the face pressure and tail void grouting pressure. The results from this study are expected to contribute to the development of settlement prediction models and understanding the surface settlement behavior induced by TBM excavation.

Keywords

Acknowledgement

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. 2017R1A5A1014883). The first author is supported by the Innovative Talent Education Program for Smart City from Ministry of Land, Infrastructure and Transport (MOLIT).

References

  1. Anagnostou, G. and Kovari, K. (1994), "The face stability of slurry-shield-driven tunnels", Tunn. Undergr. Sp. Tech., 9(2), 165-174. https://doi.org/10.1016/0886-7798(94)90028-0.
  2. Carranza-Torres, C. (2004), "Elasto-plastic solution of tunnel problems using the generalized form of the Hoek-Brown failure criterion", Int. J. Rock Mech., 41(1), 629-639. https://doi.org/10.1016/j.ijrmms.2004.03.111.
  3. Chakeri, H., Ozcelik, Y. and Unver, B. (2013), "Effects of important factors on surface settlement prediction for metro tunnel excavated by EPB", Tunn. Undergr. Sp. Tech., 36, 14-23. https://doi.org/10.1016/j.tust.2013.02.002.
  4. Comodromos, E.M., Papadopoulou, M.C. and Konstantinidis, G. K. (2014), "Numerical assessment of subsidence and adjacent building movements induced by TBM-EPB tunneling", J. Geotech. Geoenviron. Eng., 140(11), 04014061. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001166.
  5. Davis, E.H., Gunn, M.J., Mair, R.J. and Seneviratine, 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.
  6. Goh, A.T. and Hefney, A.M. (2010), "Reliability assessment of EPB tunnel-related settlement", Geomech. Eng., 2(1), 57-69. https://doi.org/10.12989/gae.2010.2.1.057.
  7. Golpasand, M.R., Do, N.A., Dias, D. and Nikudel, M. (2018), "Effect of the lateral earth pressure coefficient on settlements during mechanized tunneling", Geomech. Eng., 16(6), 643-654. https://doi.org/10.12989/gae.2018.16.6.643.
  8. Hasanpour, R. (2014), "Advance numerical simulation of tunneling by using a double shield TBM", Comput. Geotech., 57, 37-52. https://doi.org/10.1016/j.compgeo.2014.01.002.
  9. KDS 27 25 00. (2016), TBM, Korea Construction Standards Center; Korea.
  10. Kim, D., Pham, K., Park, S., Oh, J.Y. and Choi, H. (2020), "Determination of effective parameters on surface settlement during shield TBM", Geomech. Eng., 21(2), 153-164. https://doi.org/10.12989/gae.2020.21.2.153.
  11. Kim, J., Kim, J., Lee, J. and Yoo, H. (2018a), "Prediction of transverse settlement trough considering the combined effects of excavation and groundwater depression", Geomech. Eng., 15(3), 851-859. https://doi.org/10.12989/gae.2018.15.3.851.
  12. Kim, K., Oh, J., Lee, H., Kim, D. and Choi, H. (2018b), "Critical face pressure and backfill pressure in shield TBM tunneling on soft ground", Geomech. Eng., 15(3), 823-831. https://doi.org/10.12989/gae.2018.15.3.823.
  13. Lambrughi, A., Rodriguez, L.M. and Castellanza, R. (2012), "Development and validation of a 3D numerical model for TBM-EPB mechanised excavations", Comput. Geotech., 40, 97-113. https://doi.org/10.1016/j.compgeo.2011.10.004.
  14. Mair, R.J. and Taylor, R.N. (1997), "Theme lecture: Bored tunnelling in the urban environment", Proceedings of the 14th Int. Conf. Soil Mech. and Found. Eng., Rotterdam, September.
  15. Melis, M., Medina, L., & Rodriguez, J. M. (2002), "Prediction and analysis of subsidence induced by shield tunnelling in the Madrid Metro extension", Can. Geotech. J., 39(6), 1273-1287. https://doi.org/10.1139/t02-073.
  16. Moeinossadat, S.R. and Ahangari, K. (2019), "Estimating maximum surface settlement due to EPBM tunneling by Numerical-Intelligent approach-A case study: Tehran subway line 7", Transp. Geotech., 18, 92-102. https://doi.org/10.1016/j.trgeo.2018.11.009.
  17. O'Reilly, M.P. and New, B.M. (1982), "Settlements above tunnels in the United Kingdom-their magnitude and prediction", Tunnelling, 82, (No. Monograph).
  18. Peck, R.B. (1969), "Deep excavations and tunneling in soft ground", Proceedings of the 7th ICSMFE, 225-290.
  19. Selby, A.R. (1988), "Surface movements caused by tunnelling in two-layer soil", Geological Society, London, Engineering Geology Special Publications, 5(1), 71-77. https://doi.org/10.1144/GSL.ENG.1988.005.01.05.
  20. Sugiyama, T., Hagiwara, T., Nomoto, T., Nomoto, M., Ano, Y., Mair, R.J. and Soga, K. (1999), "Observations of ground movements during tunnel construction by slurry shield method at the Docklands Light Railway Lewisham Extension-East London", Soils Found., 39(3), 99-112. https://doi.org/10.3208/sandf.39.3_99.
  21. Suwansawat, S. and Einstein, H. H. (2007), "Describing settlement troughs over twin tunnels using a superposition technique", J. Geotech. Geoenviron. Eng., 133(4), 445-468. https://doi.org/10.1061/(ASCE)1090-0241(2007)133:4(445).