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2016 Vol.15, Issue 2 Preview Page
Effect of Separation Between Main and Divergent Tunnels in Divergence Section of Double-Deck Tunnel on the Stability

복층터널 분기구에서의 터널 이격에 따른 안정성 영향

You-Sung La1
,
Bum-Joo Kim2*
나 유성1
,
김 범주2*
1Graduate Student, Department of Civil and Environmental Engineering, Dongguk University
2Member, Associate Professor, Department of Civil and Environmental Engineering, Dongguk University
*교신저자. *Corresponding Author. 
30 June 2016. pp. 45-54
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Abstract

Double deck tunnels are considered to have a large demand in a near future for solving traffic congestion problems and overcoming the limitations in constructing new tunnels. This study presents a numerical investigation using finite element (FE) analysis on the behaviors of the tunnels and the stability of pillars in a divergence section where single tunnel is diverged from a main line double deck tunnel. The effects of the separation distance between the diverged and the main tunnels and the ground condition were examined through the FE analysis by varying the separation distance from 0.1D to 2.0D (D: diameter of main tunnel) and the rock class from class I to V, respectively, and the analysis results were compared with those using empirical methods, strength-stress ratio, and the volume of interference. The FE analysis results indicated that the separation distance has a larger effect on tunnel behaviors, compared with the rock strength, and a single tunnel with a large cross section is more favorable than two separated tunnels for tunnel stability when the separation distance is below 0.7D.

Keywords
Double-deck tunnel
Divergence
Separation Distance
Tunnel stability

본 연구에서는 증가하는 도심지 정체와 신설터널 건설에 따른 여러 제약의 문제를 해소하는 방안으로 향후 국내에서 수요가 증가할 것으로 전망되는 대심도 지하도로를 복층터널로 건설시 본선 복층터널에서 단층터널로 분기가 되는 구간의 터널 거동과 본선과 분기터널간의 필라 안정성을 수치해석을 통하여 검토하였다. 이를 위해 본선터널과 분기터널의 이격거리를 본선터널의 직경(D)을 기준으로 0.1D부터 2.0D까지 변화하는 조건과 지반조건을 암반등급에 따라 1∼5등급으로 변화하는 조건들에 대하여 유한요소해석을 수행하였으며, 터널의 전체적인 거동과 함께 그 결과를 기반으로 기존의 경험식 등을 이용한 안전율, 강도-응력비, 그리고 간섭체적비를 산정하여 굴착에 따른 안정성 영향을 검토하였다. 검토 결과 수치해석결과를 이용해 산정된 강도-응력비와 간섭체적비는 경험식을 이용한 방법에 비해 암반강도보다는 이격거리가 안정성에 더욱 크게 영향을 미침을 나타내었고, 그에 따라 본선과 분기터널의 이격거리가 0.7D 이하인 경우는 본선과 분기터널을 모자 형태의 하나의 대단면으로 시공하는 것이 안정성 측면에서 유리한 것으로 판단되었다.

References
1
Design Guidelines for Road. (2002), Korean Expressway Corporation.
2
Hoek. E., Brown, E.T. (1980), “Empirical Strength Criterion for Rock Masses”, J. Geotech Engineering Div. ASCE Vol.106, pp.1013-1035.
3
Jung, Y.J., Song, H.C., Lee, S.H., Shin, S.H., Lee, S.B. (2007) “Study of rock pillar stability and reinforcement methods for closely-spaced tunnels”, Korean Society for Rock Mechanics, Special Symposium, pp.486-500.
4
Kang, C.M. (2008), “Big Close Reinforce Parallel Tunnel Section Applies Pilla and Reliability Evaluation”, A master's thesis, Graduate School, Kyungpook National University.
5
Kang, J.G., Yang, H.S., Jang, S.J. (2014), “Stability Analysis of Rock Pillar in the Diverging Area of Road Tunnel”, J. of the Korean Society for Rock Mech, Vol.24, No.5, pp.344-353.
6
Kim, G.H., Choi, J.D., Jun, D.C., Shin, I.J., Sim, D.H. (2010), “A Case Study for the 1st Double-level Tunnel for Light vehicle in Urban Area in Korea”, Korean Geotechnical Society, Fall National Conference, pp.1302-1313.
7
Kim, H.M. (1997), “Effect of interference and Ground Movement by Twin Tunnelling”, J. of the Korean Society for Rock Mech, Vol.7, pp.136-147.
8
Matsuda, T. (1998), “Ground Behavior and Settlement Control of Twin Tunnels in Soil Ground” Tunnels and Metropolises, Vol.16, No.2, pp.1193-1198.
9
Peck, R.B. (1969), “Deep excavations and tunneling in soft grounding”. 7th Internation Conferences, Soil Mechanics and Foundation Engineering, pp.225-290.
10
Ryu, H.S. (2014), “The Stability Estimation of Near Parallel Tunnel Pillar at Multi-layered Soil with Shallow Depth”, A master's thesis, Graduate School, Chungbuk National University.
11
Sourcebook of Design Practical Affair for Tunnel. (2000), Korean Expressway Corporation.
12
Standard Specification for Tunnel. (2009), Ministry of Land, Transport and Maritime Affairs.
Information
  • Publisher :Korean Geosythetics Society
  • Publisher(Ko) :한국지반신소재학회
  • Journal Title :Journal of the Korean Geosynthetics Society
  • Journal Title(Ko) :한국지반신소재학회 논문집
  • Volume : 15
  • No :2
  • Pages :45-54
  • Received Date : 2016-03-31
  • Revised Date : 2016-05-04
  • Accepted Date : 2016-06-13
  • DOI :https://doi.org/10.12814/jkgss.2016.15.2.045
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