Journal of Korean Tunnelling and Underground Space Association (한국터널지하공간학회 논문집)

Korean Tunnelling and Underground Space Association (한국터널지하공간학회)
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A study on the effect of the pile tip deformations on the pile behaviour to shield TBM tunnelling

Shield TBM 터널시공으로 유발된 말뚝선단의 변형이 말뚝거동에 미치는 영향에 대한 연구

  • Young-Jin Jeon (College Institute of Industrial Technology, Kangwon National University) ;
  • Byung-Soo Park (Dept. of Civil Engineering, Kangwon State University) ;
  • Young-Nam Choi (Center for Climate Change Research, Chungnam Institute) ;
  • Cheol-Ju Lee (Dept. of Civil Engineering, Kangwon National University)
  • 전영진 (강원대학교 산업기술연구소) ;
  • 박병수 (강원도립대학교 건설지적토목과) ;
  • 최영남 (충남연구원 기후변화연구센터) ;
  • 이철주 (강원대학교 토목공학과)
  • Received : 2024.04.05
  • Accepted : 2024.05.09
  • Published : 2024.05.31
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Abstract

In the current work, a series of three-dimensional finite element analyses have been carried out to understand the behaviour of pre-existing single piles and pile groups to adjacent Shield TBM tunnelling by considering various reinforcement conditions. The numerical modelling has analysed the effect of the pile cutting, ground reinforcement and pile cap reinforcement. The analyses concentrate on the ground settlements, the pile head settlements, the axial pile forces and the shear stress transfer mechanism at the pile-soil interface. In all cases of the pile tips supported by weathered rock, the distributions of shear stresses presented a similar trend. Also, when the pile tips were cut, tensile forces or compressive forces were induced on the piles depending on the relative positions of the piles. Furthermore, when the pile tips are supported by weathered rock, approximately 70% of the load is supported by surface friction, and only the remaining 30% is supported by the pile tip. Furthermore the final settlement of the piles without reinforcement showed approximately 70% more settlement than the piles for which ground reinforcement is considered. It has been found that the ground settlements and the pile settlements are heavily affected by the pile cutting and reinforcement conditions. The behaviour of the single pile and group piles, depending on the pile cutting, conditions of ground and pile cap reinforcement, has been extensively examined and analysed by considering the key features in great details.

본 연구에서는 Shield TBM 터널 근접 시공으로 인한 기 존재하는 단독말뚝 및 군말뚝의 공학적 거동을 파악하기 위해 다양한 보강조건을 고려한 3차원 유한요소해석을 수행하였다. 수치해석에서는 말뚝 절단, 지반보강 및 기초판 보강을 고려하여 말뚝의 거동을 분석하였으며, 터널굴착으로 유발되는 지반침하, 말뚝두부 침하, 말뚝의 축력 및 말뚝-지반 사이 경계면에서 발생하는 전단응력을 고찰하였다. 말뚝선단이 풍화암에 지지되는 모든 말뚝에서는 전단응력의 분포가 비슷한 경향을 보였으며, 말뚝선단이 절단되는 말뚝의 경우 말뚝의 상대적 위치에 따라 인장력 혹은 압축력이 동시에 발생하는 것으로 나타났다. 또한, 말뚝선단이 풍화암에 지지된 경우 약 70%가 주면마찰력에 지지되며, 나머지 약 30%가 말뚝선단에 지지되는 것으로 분석되었다. 추가적으로 보강을 고려하지 않은 말뚝의 경우 그라우팅 보강을 실시한 말뚝에 비해 최종침하가 약 70% 크게 발생하였다. 말뚝선단 절단 및 보강조건 유무에 따라 지반 침하와 말뚝 침하가 큰 영향을 받는 것으로 조사되었으며, 본 연구를 통해 말뚝절단, 지반보강 및 기초판 보강 조건에 따른 단독말뚝 및 군말뚝의 거동에 영향을 미치는 주요인자를 심도있게 고찰하였다.

Keywords

Acknowledgement

본 연구는 정부(과학기술정보통신부)의 재원으로 한국연구재단의 지원을 받아 수행된 연구임(RS-2023-00278033) 또한 2024년도 정부(교육부)의 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업임(No. 2022R1A6A3A01085973).

References

  1. Brinkgreve, R.B.J., Kumarswamy, S., Swolfs, W.M. (2015), Reference manual, Plaxis 3D 2015 User's Manual, Delft, pp. 1-284.
  2. Cheng, C.Y., Dasari, G.R., Chow, Y.K., Leung, C.F. (2007), "Finite element analysis of tunnel-soil-pile interaction using displacement controlled model", Tunnelling and Underground Space Technology, Vol. 22, No. 4, pp. 450-466.
  3. Choi, Y.G., Park, J.H., Woo, S.B., Jeong, Y.J. (2003), "Reinforcing effect of FRP multi-step grouting for NATM tunnel through weathered zone", Proceedings of the KSCE 2003 Convention Program, Seoul, pp. 4805-4810.
  4. Davisson, M.T. (1972), "High capacity piles", Proceedings of the Lecture Series in Innovations in Foundation Construction, ASCE, Illinois Section, Chicago, pp. 81-112.
  5. Dias, T.G.S., Bezuijen, A. (2014a), "Pile tunnel interaction: Literature review and data analysis", Proceedings of the ITA World Tunnel Congress 2014, Iguassu Falls, Brazil, pp. 1-10.
  6. Dias, T.G.S., Bezuijen, A. (2014b), "Pile-tunnel interaction: A conceptual analysis", Proceedings of the 8th International Symposium on Geotechnical Aspects of Underground Construction in Soft Ground, CRC Press, Seoul, pp. 251-255.
  7. Hartono, E., Leung, C.F., Shen, R.F., Chow, Y.K., Ng, Y.S., Tan, H.T., Hua, C.J. (2014), "Behaviour of pile above tunnel in clay", Physical Modelling in Geotechnics, pp. 833-838.
  8. Hong, Y., Soomro, M.A., Ng, C.W.W. (2015), "Settlement and load transfer mechanism of pile group due to side-by-side twin tunnelling", Computers and Geotechnics, Vol. 64, pp. 105-119.
  9. Jacobsz, S.W. (2002), The effects of tunnelling on piled foundations, Ph.D. Thesis, University of Cambridge, pp. 51-180.
  10. Jeon, Y.J., Jeon, S.C., Jeon, S.J., Lee, C.J. (2020a), "Study on the behaviour of pre-existing single piles to adjacent shield tunnelling by considering the changes in the tunnel face pressures and the locations of the pile tips", Geomechanics and Engineering, Vol. 21, No. 2, pp. 187-200.
  11. Jeon, Y.J., Jeon, S.C., Jeon, S.J., Lee, C.J. (2020b), "A study on the behaviour of pre-existing single piles to adjacent shield TBM tunnelling from three-dimensional finite element analyses", Journal of Korean Tunnelling and Underground Space Association, Vol. 22, No. 1, pp. 23-46.
  12. Jeon, Y.J., Kim, J.S., Jeon, S.C., Jeon, S.J., Park, B.S., Lee, C.J. (2018), "A study on the behaviour of single piles to adjacent Shield TBM tunnelling by considering face pressures", Journal of Korean Tunnelling and Underground Space Association, Vol. 20, No. 6, pp. 1003-1022.
  13. Jeon, Y.J., Kim, S.H., Kim, J.S., Lee, C.J. (2017), "A study on the effects of ground reinforcement on the behaviour of pre-existing piles affected by adjacent tunnelling", Journal of Korean Tunnelling and Underground Space Association, Vol. 19, No. 3, pp. 389-407.
  14. Jeon, Y.J., Kim, S.H., Lee, C.J. (2015), "A study on the effect of tunnelling to adjacent single piles and pile groups considering the transverse distance of pile tips from the tunnel", Journal of Korean Tunnelling and Underground Space Association, Vol. 17, No. 6, pp. 637-652.
  15. Jeon, Y.J., Lee, C.J. (2015), "A study on the behaviour of single piles to adjacent tunnelling in stiff clay", Journal of the Korean Geo-Environmental Society, Vol. 16, No. 6, pp. 13-22.
  16. Jeon, Y.J., Lee, C.J. (2023), "Analysis of pile group behaviour to adjacent tunnelling considering ground reinforcement conditions with assessment of stability of superstructures", Geomechanics and Engineering, Vol. 33, No. 5, pp. 463-475.
  17. Jeon, Y.J., Lee, G.S., Lee, J.C., Batbuyan, C., Lee, C.J. (2022), "A study on platform-based preliminary design guidelines associated with the behaviour of piles to adjacent tunnelling", Journal of Korean Tunnelling and Underground Space Association, Vol. 24, No. 2, pp. 129-151.
  18. Kaalberg, F.J., Teunissen, E.A.H., Van Tol, A.F., 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 the 5th International Conference of TC28 of the ISSMGE, Amsterdam, pp. 123-131.
  19. Lee, C.J. (2012a), "Three-dimensional numerical analyses of the response of a single pile and pile groups to tunnelling in weak weathered rock", Tunnelling and Underground Space Technology, Vol. 32, pp. 132-142.
  20. Lee, C.J. (2012b), "Behaviour of single piles and pile groups in service to adjacent tunnelling conducted in the lateral direction of the piles", Journal of Korean Tunnelling and Underground Space Association, Vol. 14, No. 4, pp. 337-356.
  21. Lee, C.J. (2012c), "The response of a single pile and pile groups to tunnelling performed in weathered rock", KSCE Journal of Civil and Environmental Engineering Research, Vol. 32, No. 5C, pp. 199-210.
  22. Lee, C.J., Chiang, K.H. (2007), "Responses of single piles to tunnelling-induced soil movements in sandy ground", Canadian Geotechnical Journal, Vol. 44, No. 10, pp. 1224-1241.
  23. Lee, C.J., Jeon, Y.J. (2015), "A study on the effect of the locations of pile tips on the behaviour of piles to adjacent tunnelling", Journal of Korean Tunnelling and Underground Space Association, Vol. 17, No. 2, pp. 91-105.
  24. Lee, C.J., Jeon, Y.J., Kim, S.H., Park, I.J., (2016), "The influence of tunnelling on the behaviour of preexisting piled foundations in weathered soil", Geomechanics and Engineering, Vol. 11, No. 4, pp. 553-570.
  25. Lee, Y.J. (2008), "A boundary line between shear strain formations associated with tunneling adjacent to an existing piled foundation", Journal of Korean Tunnelling and Underground Space Association, Vol. 10, No. 3, pp. 283-293.
  26. Liu, C., Zhang, Z., Regueiro, R.A. (2014), "Pile and pile group response to tunnelling using a large diameter slurry shield - Case study in Shanghai", Computers and Geotechnics, Vol. 59, pp. 21-43.
  27. Mair, R.J., Williamson, M.G. (2014), "The influence of tunnelling and deep excavation on piled foundations", Proceedings of the Geotechnical Aspects of Underground Construction in Soft Ground, Seoul, pp. 21-30.
  28. Marshall, A.M. (2009), Tunnelling in sand and its effect on pipelines and piles, Ph.D. Thesis, University of Cambridge, pp. 43-180.
  29. Mroueh, H., Shahrour, I. (2008), "A simplified 3D model for tunnel construction using tunnel boring machines", Tunnelling and Underground Space Technology, Vol. 23, No. 1, pp. 38-45.
  30. Ng, C.W.W., Lu, H. (2014), "Effects of the construction sequence of twin tunnels at different depths on an existing pile", Canadian Geotechnical Journal, Vol. 51, No. 2, pp. 173-183.
  31. Ng, C.W.W., Lu, H., Peng, S.Y. (2013), "Three-dimensional centrifuge modelling of the effects of twin tunnelling on an existing pile", Tunnelling and Underground Space Technology, Vol. 35, pp. 189-199.
  32. Ng, C.W.W., Soomro, M.A., Hong, Y. (2014), "Three-dimensional centrifuge modelling of pile group responses to side-by-side twin tunnelling", Tunnelling and Underground Space Technology, Vol. 43, pp. 350-361.
  33. Pang, C.H. (2006), The effects of tunnel construction on nearby pile foundation, Ph.D. Thesis, The National University of Singapore, pp. 24-170.
  34. Plaxis 3D (2024), Reference manual, Plaxis 3D User's Manual, pp. 75-130.
  35. Selemetas, D. (2006), The response of full-scale piles and piled structures to tunnelling, Ph.D. Thesis, University of Cambridge, pp. 44-132.
  36. Selemetas, D., Standing, J.R. (2017), "Response of full-scale piles to EPBM tunnelling in London Clay", Geotechnique, Vol. 67, No. 9, pp. 823-836.
  37. Soomro, M.A., Ng, C.W.W., Memon, N.A., Bhanbhro, R. (2018), "Lateral behaviour of a pile group due to side-by-side twin tunnelling in dry sand: 3D centrifuge tests and numerical modelling", Computers and Geotechnics, Vol 101, pp. 48-64.
  38. University of Cambridge: 2020 Case Studies, Monitoring of under-reamed piles during tunnelling interception using distributed fibre optic sensing, https://www-smartinfrastructure.eng.cam.ac.uk/projects-andcase-studies/2020-case-studies/monitoring-under-reamed-piles-during-tunnelling (March 25, 2024).
  39. Wang, X., Yuan, D. (2023), "Research on the interaction between the pile and shield machine in the process of cutting a reinforced concrete pile foundation", Applied Sciences, Vol. 13, No. 1, 245.
  40. Williamson, M.G. (2014), Tunnelling effects on bored piles in clay, Ph.D. Thesis, University of Cambridge, pp. 61-121.
  41. Zhang, C., Zhao, Y., Zhang, Z., Zhu, B. (2021), "Case study of underground shield tunnels in interchange piles foundation underpinning construction", Applied Sciences, Vol. 11, No. 4, 1611.