Assessment of minimum pillar width and reinforcement of parallel tunnel using numerical analysis and field monitoring

Yong-Koan An; Suk-Min Kong; Yong-Joo Lee

doi:10.9711/KTAJ.2014.16.3.299

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2014 Vol.16, Issue 3 Preview Page Next Page

Assessment of minimum pillar width and reinforcement of parallel tunnel using numerical analysis and field monitoring 수치해석과 현장계측을 통한 병렬터널의 최소 필라폭과 보강에 대한 평가

31 May 2014. pp. 299-310

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Abstract

Nationally, tunnel and underground constructions are necessary for the environmental sustainability and the efficient use of land space. For the importance of eco-friendly circumstances, 2-arch or large road tunnel has been designed so far. However, such a 2-arch or large tunnel has problems in terms of cost, constructability, construction period, and maintenance. Therefore, in this study, tunnel behavior and stability of rock pillar according to the pillar width and cover depth for parallel tunnels are investigated by performing FE analysis and using empirical formula. According to the results, Rock pillar is reinforced for distributed vertical load by Tie-Bolt due to unpredicted ground deformation, and the reinforced rock pillar’s behaviour from the FE analysis shows a quite good agreement with field measurement. According to ground conditions, if the pillar width of the parallel tunnels is reduced, it can be more efficient in use of the tunnel space compared to previous tunnels.

Keywords

Parallel tunnel

Numerical analysis

Empirical formula

Pillar width

Field measurement

국가적으로 국토의 효율적 활용과 친환경성 등으로 인해 터널과 같은 지하공간 건설이 필요하다. 친환경적 요소의 중요성을 감안할 때, 산악지에 형성되는 도로건설에 대해 2-아치 및 대단면 터널로 계획되나 경제성, 시공성, 공사기간, 유지관리 등의 문제점을 가지고 있다. 따라서 본 연구에서는 2차로의 국도터널을 기준으로 현장조건과 지반조건을 고려하여 터널별 이격거리와 토피고를 변화시켜 경험식과 수치해석적으로 필라부의 안전성을 평가하였으며, 해석 프로그램으로 유한요소법을 적용한 Plaxis 2D를 활용하여 터널의 최소 필라폭 선정과 전체적인 터널의 거동특성을 분석하였다. 분석결과, Tie-Bolt에 의한 필라보강은 연직하중을 분산시켜 안전적인 근접병렬터널 계획이 가능하며, 터널 필라의 거동은 현장계측 결과와 잘 일치하는 것으로 나타났으며, 지반조건에 따라 터널 필라폭을 축소시킨다면 이전의 터널에 비해 효율적인 터널 활용이 가능하다.

키워드

병렬터널

수치해석

경험식

필라폭 (필라 이격거리)

현장계측

References

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2.Hoek, E.I., Brown, E.T. (1997), “Practical estimates of rock mass strength”, Int. J. of Rock Mech. Min. Sci., Vol. 34, No. 8, pp. 1,165-1,186.

3.Kim, D.S., Kim, Y.G. (2007), “A study on the stability analysis for asymmetry parallel tunnel with rock pillar”, Tunnelling and Underground Space Technology, Vol. 9, No. 4, pp. 387-401.

4.Lee, M.H., Kim, B.j., Jang, Y.S., Yun, J.N., Park, H.G. (2013), “Behavior and pillar stability of enlarged existing parallel tunnels”, Journal of Korean Tunnelling and Underground Space Association, Vol. 15, pp. 537-546.

5.Matsuda, T., Toyosato, E., Igarashi, M., Nashimoto, Y., Sugiyama, T. (1997), “A study on design methods for twin tunnels constructed by the single drift and central pier method”, Proceeding of Studies on Tunnel Engineering, Vol. 7.

6.Peck, R.B. (1969), “Deep excavation and tunneling in soft ground”, Proc. 7th International Conferences, Soil Mechanics and Foundation Engineering, pp. 225-290.

7.Plaxis (2002), Ver. 8.2, PLAXIS BV, (2002), The Netherlands.

8.Sin, Y.W., Kim, Y.G. (2010), “Review of mechanical behaviors of pillar in large parallel tunnel”, Tunnelling and Underground Space Technology, Vol. 20, No. 3, pp. 131-144.

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 : 16
No :3
Pages :299-310
Received Date : 2014-04-21
Revised Date : 2014-05-09
Accepted Date : 2014-05-13
DOI :https://doi.org/10.9711/KTAJ.2014.16.3.299

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

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