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

Korean Tunnelling and Underground Space Association (한국터널지하공간학회)
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Hydraulic convergence and confinement behavior characteristics of tunnels

터널의 수리적 수렴 및 제어 거동특성

  • Jae-Ho Jeong (GEO EXPERT GROUP Co., Ltd.) ;
  • Seung-Hyun Kim (Dept. of Civil Engineering, Konkuk University) ;
  • Hyun Il You (Dept. of Civil Engineering, Konkuk University) ;
  • Jong-Ho Shin (Dept. of Civil and Environmental Engineering, Konkuk University)
  • 정재호 ((주)지오엑스퍼트그룹) ;
  • 김승현 (건국대학교 인프라시스템공학과) ;
  • 유현일 (건국대학교 인프라시스템공학과) ;
  • 신종호 (건국대학교 사회환경공학부)
  • Received : 2024.08.01
  • Accepted : 2024.09.03
  • Published : 2024.09.30
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Abstract

Excavation of tunnels below the groundwater table changes the hydraulic boundary conditions, causing flow towards the excavation face. Inflow into a tunnel is generally influenced by pre-excavation grouting, shotcrete lining, drainage system implementation, and the hydraulic deterioration of the drainage system. From the perspective of continuum theory, the groundwater inflow behavior due to excavation is very similar to the tunnel excavation behavior known as the convergence-confinement method. The groundwater inflow behavior due to tunnel excavation can be explained by the hydraulic convergence, while the behavior of shotcrete lining in limiting inflow can be inferred as hydraulic confinement. This study investigates the hydraulic convergence and confinement behavior using theoretical and numerical methods due to tunnelling. It is confirmed that the hydraulic convergence-confinement is exactly the same as the mechanical convergence-confinement concept. It is identified that the behavior is governed by the tunnel geometry, grout thickness and permeability, as well as the thickness and permeability of the support materials, such as shotcrete.

지하수위 아래에서 이루어지는 터널 굴착은 수리경계조건을 변화시켜 굴착면을 향한 흐름을 유발한다. 터널 내 유입량은 굴착 전 시행된 그라우팅, 숏크리트 타설 및 방배수 시스템의 도입, 배수재의 수리적 열화 등에 영향을 받는다. 연속체이론 관점에서 굴착에 따른 지하수의 유입거동은 터널굴착 거동 이론인 내공변위-제어개념과 유사하다. 터널굴착에 따른 지하수 유입거동은 수리적 수렴거동(hydraulic convergence) 개념으로 설명할 수 있고, 지보재인 숏크리트가 유입량을 억제하는 거동은 수리적 제어거동(hydraulic confinement)으로 유추할 수 있다. 본 연구에서는 이론과 수치해석을 이용하여 터널 굴착에 따른 수리적 convergence 및 confinement 거동특성을 조사하였다. 터널 굴착에 따른 수리적 유입량 제어거동은 역학적 내공변위 제어 개념과 일치하며, 터널의 기하학적 조건, 그라우트 두께와 투수성, 그리고 숏크리트와 같은 지보재의 두께와 투수성에 지배됨을 확인하였다.

Keywords

Acknowledgement

이 논문은 건국대학교 지원에 의하여 작성되었음.

References

  1. El Tani, M. (1999), "Water inflow into tunnels", Proceedings of the World Tunnel Congress ITA-AITES, Norway, Oslo, pp. 61-70.
  2. Fernandez, G., Alvarez, T.A. (1994), "Seepage-induced effective stresses and water pressures around pressure tunnels", Journal of Geotechnical Engineering, No. 120, Vol. 1, pp. 108-128. https://doi.org/10.1061/(ASCE)0733-9410(1994)120:1(108)
  3. Freeze, R.A., Cherry, J.A. (1979), Groundwater, Prentice-Hall Inc., Englewood, NJ, pp. 490-491.
  4. Goodman, R.E., Moye, D.G., Van Schalkwyk, A., Javandel, I. (1965), "Ground water inflows during tunnel driving", Bulletin of the International Association of Engineering Geologists 2, No. 1, pp. 39-56.
  5. Joo, E.J., Shin, J.H. (2014), "Relationship between water pressure and inflow rate in underwater tunnels and buried pipes", Geotechnique, Vol. 64, No. 3, pp. 226-231. https://doi.org/10.1680/geot.12.P.185
  6. Lei, S. (1999), "An analytical solution for steady flow into a Ttonnel", Groundwater, Vol. 37, No. 1, pp. 23-26. https://doi.org/10.1111/j.1745-6584.1999.tb00953.x
  7. Panet, M., Sulem, J. (1995), Le Calcul des Tunnels par la Methode Convergence-Confinement, Presses de l'Ecole Nationale des Ponts et Chaussees, Paris, pp. 61-158.
  8. Shin, J.H. (2010), "Analytical and combined numerical methods evaluating pore water pressure on tunnels", Geotechnique, Vol. 60, No. 2, pp. 141-145. https://doi.org/10.1680/geot.8.T.035
  9. Shin, J.H., Addenbrooke, T.I., Potts, D.M. (2002), "A numerical study of the effect of groundwater movement on long-term tunnel behaviour", Geotechnique, Vol. 52, No. 6, pp. 391-403. https://doi.org/10.1680/geot.2002.52.6.391
  10. Shin, J.H., Potts, D.M., Zdravkovic, L. (2005), "The effect of pore-water pressure on NATM tunnel linings in decomposed granite soil", Canadian Geotechnical Journal, Vol. 42, No. 6, pp. 1585-1599. https://doi.org/10.1139/t05-072
  11. Shin, J.H., Shin, Y.S., Kim, S.H., Shin, H.S. (2007), "Evaluation of residual pore water pressure on linings for undersea tunnels", Chinese Journal of Rock Mechanics and Engineering, Vol. 26, No. 2, pp. 3682-3688.
  12. Shin, Y.J. (2007), Elasto-plastic ground response of underwater tunnels considering seepage forces, Thesis for the Degree of Doctor of Philosophy, Korea University, pp. 33-82.