A study on the flow behavior around shallow tunnels and its numerical modelling

Jong-Ho* Shin; Min-Gu Choi; So-Ra Kang; Taek-Soo Nam

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2008 Vol.10, Issue 1 Preview Page Next Page

A study on the flow behavior around shallow tunnels and its numerical modelling 천층터널 주변의 흐름거동 및 수치 해석적 모델링기법 연구

31 March 2008. pp. 37-47

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Abstract

Design and construction of tunnels require understanding the influence of groundwater. Particularly, it is essential to know how the drainage conditions at the tunnel boundary affect flow behavior of ground adjacent to the tunnels. In this study flow behavior of a leaking tunnel was investigated using physical model tests for tunnel depths and various hydraulic boundary conditions. Particular concerns were given to flow lines toward tunnels. Test results showed that the boundary conditions hardly influence on flow patterns and time required to reach steady state conditions. It is revealed that with an increase in water depth, flow lines concentrated to the drain holes. The physical tests were numerically simulated. Numerical results showed that the flow behavior was represented appropriately by considering filter-drain hole drainage rather than boundary drainage all over the lining.

Keywords

Leaking tunnel

hydraulic boundary conditions

physical model test

numerical simulation

터널 설계 및 시공시 지하수 영향에 대한 정확한 이해가 필요하며, 이를 위해 터널 주변의 흐름거동을 파악하는 것이 중요하다. 본 연구에서는 지하수 아래 건설된 배수형 천층터널에 대한 모형실험을 실시하여 주변 지하수 흐름조건과 지반의 토피고에 따른 터널 주변의 지하수 흐름거동을 조사하였다. 실험결과 정상류/부정류의 지하수 흐름조건은 터널내 유입량이나 도달시간에는 영향을 미칠 수 있으나, 터널 주변 흐름거동에는 큰 영향을 미치지 못함을 확인할 수 있었다. 또, 토피고가 증가할수록 배수공이 위치한 터널 하부로의 유선 집중현상이 뚜렷하게 관찰되었다. 모형실험에 대한 수치해석결과, 배수형 천층터널 주변의 흐름거동을 수치해석으로도 재현 가능함을 확인하였다. 배수형 천층터널의 경우 수리경계조건이 터널주면 유출이 아닌 배수공 유출로 모사하는 것이 보다 타당함을 보였다.

키워드

배수형 천층터널

수리경계조건

모형실험

수치 해석적 모델링

References

1.Atkinson, J.H., Mair, R.J. (1983), Loads on leaking and watertight tunnel lining, sewers and buried pipes due to groundwater, Geotechnique 33, No. 3, pp. 341-344.

2.Fernandez, G. (1994), Behavior of pressure tunnels and guidelines for liner design, Journal of Geotechnical Engineering, Vol. 120, No. 10-12, pp. 1768-1791.

3.Fernandez, G., Alvarez, T.A. Jr. (1992), Seepage-indeced effective stresses and water pressures around pressure tunnels, Journal of Geotechnical Engineering, Vol. 120, pp. 108-128.

4.Harr, M.E. (1962), Goundwater and Seepage, McGraw-Hill, New York, N.Y.

5.Jong-ho Shin (2002), Numerical analysis of tunnelling in decomposed granite soil, Ph.D. Dissertation, Imperial College, London, UK.

6.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 52, No. 6, pp. 391-403.

7.Shin, Y.J. (2007), Elasto-plastic ground response of underwater tunnels considering seepage forces, Ph.D. Dissertation, Korea University.

Information

Publisher :Korean Tunneling and Underground Space Association
Publisher(Ko) :한국터널지하공간학회
Journal Title :Journal of Korean Tunnelling and Underground Space Association
Journal Title(Ko) :한국터널지하공간학회 논문집
Volume : 10
No :1
Pages :37-47

Journal of Korean Tunnelling and Underground Space Association ISSN:2233-8292(Print) 2287-4747(Online) 한국터널지하공간학회 논문집

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