A Study on the Behaviour of a Single Pile to Tunnelling Including Soil Slip

Soil slip을 고려한 터널굴착에 의한 단독말뚝의 거동연구

  • 이철주 (강원대학교 토목공학과)
  • Received : 2009.04.12
  • Accepted : 2009.05.26
  • Published : 2009.08.01

Abstract

Three-dimensional (3D) numerical analyses have been conducted to study the behaviour of a single pile to tunnelling. The numerical analysis has included soil slip at the pile-soil interface. In the numerical analyses the interaction between the tunnel and the pile constructed in weathered soil and rock has been analysed. The study includes the pile settlement, the relative shear displacement between the pile and the soil and the shear stresses at the interface and the axial force on the pile. In particular, the shear stress transfer mechanism at the pile-soil interface related to the tunnel advancement has been rigorously analysed. Due to changes in the relative shear displacement at the pile-soil interface during the tunnel advancement, the shear stress and the axial force distributions along the pile have been changed. Upward shear stress developed at most part of the pile (Z/L=0.0-0.8), while downward shear stress is mobilised near the pile tip (Z/L=0.8-1.0) resulting in tensile force on the pile, where Z is the pile location and L is the pile length. Some insights into the pile behaviour to tunnelling obtained from the numerical analyses will be reported and discussed.

본 연구에서는 단독말뚝의 주변에서 실시되는 터널의 굴착이 지반 및 말뚝에 미치는 영향을 3차원 수치해석을 통하여 분석하였다. 수치해석에서는 말뚝과 주변지반 사이에 경계면요소를 이용하여 소성항복 발생조건을 모델링하였다. 수치해석을 통하여 풍화토 및 풍화암에 시공된 터널과 말뚝의 상호거동에 대한 분석을 실시하였다. 수치해석을 통해 말뚝의 침하, 말뚝과 지반 경계면에서의 상대변위, 전단응력 및 말뚝의 축력변화를 분석하였다. 특히 터널의 굴착과 관련된 전단응력의 전이과정에 대한 심도있는 분석을 실시하였다. 터널굴착에 의한 말뚝-지반 경계면에서 상대변위의 변화로 인하여 말뚝에 작용하는 전단응력 및 축력의 분포가 변하게 된다. 말뚝 본체 대부분에서는 상향의 전단응력이 발생하는 반면(Z/L=0.0-0.8), 말뚝선단부근에서는(Z/L=0.8-1.0) 하향의 전단응력이 발생하여 말뚝에 인장력이 발생된다. 수치해석을 통해서 터널굴착이 말뚝 거동에 미치는 영향을 상세하게 분석하였다.

Keywords

Acknowledgement

Supported by : 국토해양부

References

  1. 대한토목학회 (2005), 제 5회 터널 시공기술 향상 대토론회, 도심지 터널 근접시공을 중심으로, 대한토목학회.
  2. 이철주, 전상현, 유남재 (2007), 터널굴착에 의한 단독말뚝의 거동, 대한토목학회 논문집, 27 (2C), pp. 121-127.
  3. Bezuijen, A. and Schrier, J.V.D. (1994), The influence of a bored tunnel on pile foundations, Centrifuge 94, (Edited by Lee & Tan), Balkema, Rottterdam, pp. 681-686.
  4. Chen, L.T., Poulos, H.G. and Loganathan, N. (1999), Pile responses caused by tunneling, Journal of Geotechnical and Geoenvironmental Engineering, 125(3), ASCE, pp. 207-215. https://doi.org/10.1061/(ASCE)1090-0241(1999)125:3(207)
  5. Chen, C. Y. and Martin, G. R. (2001), Effect of embankment slope on lateral response of piles, FLAC and numerical modeling in Geomechanics, (Billaux et al Eds), Swets & Zeitlinger, pp. 205-213.
  6. Cheng, C. Y, Dasari, G. R, Leung, C. F. and Chow, Y. K. (2003), Finite element study of tunnel-soil-pile interaction. National University of Singapore Publication, Hulme Prize Winning Paper.
  7. Cheng, C. Y, Dasari, G. R, Chow, Y. K. and Leung, C. F. (2007), Finite element analysis of tunnel-soil-pile interaction using displacement controlled model, Tunnelling and Underground Space Technology, 22, pp. 450-466. https://doi.org/10.1016/j.tust.2006.08.002
  8. Chiang, G. H. (2002), The load transfer behavior of piles caused by nearby tunneling, Master thesis, National Central University, Taiwan (in Chinese).
  9. Davisson, M. T. (1972), High capacity piles, Proceedings and Lecture Series in Innovations in Foundation Construction, ASCE, Illinois Section, pp. 82-112.
  10. Jacobsz, S.W. (2002), The effects of tunnelling on piled foundations, PhD thesis, University of Cambridge.
  11. Jacobsz, S.W. (2003), Tunnelling effects on piled foundations, Tunnels and Tunnelling international, June, pp. 28-31.
  12. Kaalberg, F.J, Teunissen, E.A.H, van Tol A.F. and Bosch, J.W. (2005), Dutch Research on the impact of shield tunneling on pile foundations, Geotechnical Aspects of Underground Construction in Soft Ground, Proceedings of 5th International Conf. of TC 28 of the ISSMGE, pp. 123-133.
  13. Lee, C. J. and Jacobsz, S.W. (2006), The Influence of Tunnelling on Adjacent Piled Foundations, ITA 2006, CD
  14. Lee, C. J. and Chiang, K. H. (2007), Responses of single piles to tunneling-induced soil movements in sandy ground, Canadian Geotechnical Journal, 44, pp. 1224-1241. https://doi.org/10.1139/T07-050
  15. Lee, G.T.K. and Ng, C.W.W. (2005), The effects of advancing open face tunneling on an existing loaded pile, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 131(2), pp. 193-201. https://doi.org/10.1061/(ASCE)1090-0241(2005)131:2(193)
  16. Lee, Y. J. (2004), Tunnelling adjacent to a row of loaded piles. PhD Thesis, University College London, University of London,
  17. Lee, Y. J. and Bassett, R. H. (2007), Influence zones for 2D pile-soil-tunnelling interaction based on model test and numerical analysis, Tunnelling and Underground Space Technology, 22, pp. 325-342. https://doi.org/10.1016/j.tust.2006.07.001
  18. Loganathan, N. and Poulos, H.G. (1998), Analytical prediction for tunnelling induced ground movements in clays. Journal of Geotechnical and Geo-environmental Engineering, ASCE, 124(9), pp. 846-856. https://doi.org/10.1061/(ASCE)1090-0241(1998)124:9(846)
  19. Mroueh, H. and Shahrour, I. (2002), Three-dimensional finite element analysis of the interaction between tunnelling and pile foundation, Int. J. Numer. Anal. Meth. Geomech., 26, pp. 217-230. https://doi.org/10.1002/nag.194
  20. Pang, C. H., Yong, K.Y., Chow, Y.K. and Wang, J. (2005), The response of pile foundations subjected to shield tunnelling, 5th Int'l Symposium Geotechnical Aspects of Underground Construction in Soft Ground, Balkema.
  21. Pang, C. H. (2006), The effects of tunnel construction on nearby pile foundation, PhD thesis, The National University of Singapore.
  22. Selemetas, D. (2005), The response of full-scale piles and piled structures to tunneling, PhD thesis, University of Cambridge.
  23. Vermeer, P. A. and Bonnier, P. G. (1991), Pile settlements due to tunneling, Proceedings of the 10th European Conference on Soil mechanics and Foundation Engineering, 2, pp. 869-872.
  24. Yong, K. Y. and Pang, C. H. (2004), Geotechnical challenges of the mass rapid transit (MRT) system in Singapore, In Malaysian Geotechnical Conference 2004, March 2004, Special Lecture.