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

Korean Tunnelling and Underground Space Association (한국터널지하공간학회)
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A numerical study on the waterproofing effect of Fan Grouting under tunnel excavation

터널 굴착 중 Fan Grouting의 차수 효과에 관한 수치해석적 연구

  • Received : 2019.01.08
  • Accepted : 2019.02.01
  • Published : 2019.03.31
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Abstract

Ground water generated under tunnel excavation has a major impact on tunnel construction and stability. Thus, effective waterproof grouting is needed to reduce the inflow of groundwater. Most tunnel designs are applying the Pre Grouting. However there are no propriety analysis for grouting material and waterproof effect. In this study, numerical analysis was performed in order to investigate the effect of waterproof with decrease of coefficient of permeability of the grouting area based on the case of grouting construction.

터널 굴착 중 발생하는 지하수는 터널 시공성 및 안정성에 중요한 영향을 끼친다. 따라서 터널의 굴착 중 발생하는 지하수의 유입을 감소시키기 위한 적절한 차수그라우팅이 필요하다. 대부분 터널 설계단계에서는 Pre Grouting을 적용하고 있으나 그라우팅 재료 및 차수효과의 적정성에 대한 분석은 미미하다. 본 연구에서는 현장의 차수 그라우팅 시공사례를 분석하고, 실측된 시공자료를 바탕으로 시공개선사항 및 그라우팅 영역의 투수계수 감소를 고려한 수치해석을 통해 차수효과를 분석하였다.

Keywords

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Fig. 1. Pre Grouting

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Fig. 3. Photos in the tunnel and layout

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Fig. 4. Manjet tube and U-GIP injection pipe

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Fig. 5. Principle of U-GIP injection pipe

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Fig. 6. Numerical model

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Fig. 7. Result of discharge and pore pressure

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Fig. 2. Fan Grouting

Table 1. Evaluation of leakage

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Table 2. Ground design parameters

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Table 3. Result of pore pressure and discharge at position of grouting

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References

  1. Cheon, B.S., Lee, Y.J., Ko, G.S., Jung, H.C., Choi, S.H. (1995), "Chemical grouting of tunnel underpassing the Han river", Proceedings of the Korean Society of Civil Engineers Conference, Seoul, Vol. 2, pp. 377-380.
  2. Do, I.W. (2014), "Performance research on cutoff grouting around the tunnel", M.S. Thesis, Graduate School of Kyungpook National University, pp. 1-49.
  3. Joo, E.J., Kim, Y.K., Shin, J.H., Kwon, O.Y. (2010), "Numerical study for the optimum grouting design of subsea tunnels", Journal of Korean Tunnelling and Underground Space Association, Vol. 12, No. 5, pp. 349-358.
  4. Seo, K.W., Baek, K.H., Kim, W.K., Jun, S.K., Kim, S.J. (2010), "Analysis of the grouting effectiveness in tunnel excavation", Proceedings of the Korean Society of Civil Engineers 36th Annual Conference, Incheon, pp. 1720-1723.
  5. You, K.H. (2011), "Analysis on the effect of strength improvement and water barrier by tunnel grouting reinforcement", Journal of Korean Tunnelling and Underground Space Association, Vol. 13, No. 4, pp. 291-304. https://doi.org/10.9711/KTAJ.2011.13.4.291
  6. You, K.H., Jie, H.K., Seo, K.W., Kim, S.J., You, D.W. (2012), "A study on the correlation between the rock mass permeability before and after grouting & injection volume and the parameters of Q system in a jointed rock mass tunnel", Journal of Korean Tunnelling and Underground Space Association, Vol. 14, No. 6, pp. 617-635. https://doi.org/10.9711/KTAJ.2012.14.6.617