Tunnel and Underground Space (터널과지하공간)

Korean Society for Rock Mechanics and Rock Engineering (한국암반공학회)
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Case Study of a Shallow Tunnelling Through Complex Strata of Sand-Gravel and Rock Mass

모래자갈과 암반의 복합지층에 시공한 저심도 터널의 사례연구

  • Kim, Cheehwan (Department of Civil and Environmental Engineering, Woosuk University)
  • Received : 2015.06.06
  • Accepted : 2015.06.24
  • Published : 2015.06.30
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Abstract

The tunnel is excavated through the alluvial layer composed of sand and gravel with groundwater deposited on rock. A portion of upper part of the tunnel is located in the alluvial layer and there are several buildings just above the curved section of the tunnel. It is necessary to prevent from sand-flowing into the tunnel due to low strength of the alluvial, high groundwater level and shallow depth of the tunnel from the ground surface. For this, the alluvial around the tunnel is pre-reinforced by umbrella arch method with multi-stage grouting through large diameter steel pipes or jet grouting before excavating the tunnel. The effect of the pre-reinforcement of the tunnel and the safety of the buildings are monitored by measurement of ground deformation occurred during tunnelling.

모래와 자갈이 암반 위에 퇴적된 지층에서 터널의 윗부분이 지하수가 많은 모래자갈층을 통과하는 상황에서 터널을 시공하였다. 지상의 일부 곡선구간에 빌딩들도 있는 저심도 터널을 안전하게 시공하기 위하여 강도가 작고 지하수가 많은 터널천정부의 모래자갈이 터널 내로 낙하하는 유사현상(sand flow)을 예방해야 하였다. 이를 위하여 대구경강관다단그라우팅이나 제트그라우팅으로 터널주변 충적층을 굴착 전에 미리 보강한 후 터널을 시공하였다. 이와 같이 터널을 보강한 효과와 지상빌딩의 안전을 시공 중 계측을 통하여 확인하였다.

Keywords

References

  1. 대림산업주식회사, 2006, 지상건물 하부통과 터널구간의 계측치 추세예측 및 역해석.
  2. 서울특별시도시기반시설본부, 2011a, 서울지하철 9호선 3단계 918공구 건설공사 지반조사보고서
  3. 서울특별시도시기반시설본부, 2011b, 서울지하철 9호선 3단계 918공구 건설공사 실시설계보고서
  4. SK건설, 2014, 지하철918공구 월간계측보고서(2014.12).
  5. Kim Cheehwan, 1990, Stress analysis and deformation behaviour of rock around underground cavern by back analysis of field measurements. Ph.D Thesis, Seoul National University.
  6. Kim Cheehwan, 2005, Stability analysis on the intersection area of subway tunnels by observational method, Tunnel & Underground Space, Journal of Korean Society for Rock Mechanics, Vol. 15, No. 1, pp. 71-79.
  7. Kim Cheehwan, 2010, Forecasting final displacement with displacement function using deformation measurements while constructing a tunnel. Tunnel & Underground Space, Journal of Korean Society for Rock Mechanics, Vol. 20, No. 6, pp. 408-420.
  8. Kim Cheehwan, 2013a, Relations between initial displacement rate and final displacement of arch settlement and convergence of a shallow tunnel, Tunnel & Underground Space, Journal of Korean Society for Rock Mechanics, Vol. 23, No. 2, 2013, pp. 110-119. https://doi.org/10.7474/TUS.2013.23.2.110
  9. Kim Cheehwan, 2013b, Measurement of tunnel arch settlements ahead of and behind the tunnel face using a horizontal inclinometer and settlement pins, Tunnel & Underground Space, Journal of Korean Society for Rock Mechanics, Vol. 23, No. 2, 2013, pp. 120-129. https://doi.org/10.7474/TUS.2013.23.2.120
  10. Kim Cheehwan, 2013c, Characteristics of Subsidence above a Shallow Tunnel Excavated in Weathered Rock Mass, Tunnel & Underground Space, Journal of Korean Society for Rock Mechanics, Vol. 23, No. 5, 2013, pp. 337-346. https://doi.org/10.7474/TUS.2013.23.5.337
  11. Mair R.J., Taylor R.N., Burland J.B., 1996, Prediction of ground movements and assessment of risk of building damage due to bored tunnelling. Geotechnical Aspects of Underground Construction in Soft Ground, pp. 713-718.
  12. Matlab, 2009, The MathWorks Inc.
  13. Nam Kee Chun, Heo Young, Kim Chi Whan, You Kwang Ho, 2002, The behavior of soil tunnels reinforced with RPUM and fiber glass. Tunnel Technology, Korean Tunnelling Association, Vol. 4, No.3, pp. 185-193.
  14. Nam Kee Chun, 2002, A study on the reinforced protection to control extrusion at the face of shallow tunnels. Ph.D Thesis, Suwon University, pp. 57-71.
  15. New B.M. and Bowers. K.H., 1994, Ground movement model validation at the Heathrow Express trial tunnel. Tunnelling 94, pp. 301-332.