All Issue

2018 Vol.20, Issue 4 Preview Page
A study for calculating factor of safety against basal heave during circular vertical shaft excavation in clay considering 3D shape

3차원 형상을 고려한 점성토 지반 원형 수직구 굴착 중 히빙에 대한 안전율 산정을 위한 연구

Seok-Jun Kang1
,
Gye-Chun Cho2
,
Jung-Tae Kim3
,
Han-Sung Kim4
,
Eun-Soo Hong5*
강 석준1
,
조 계춘2
,
김 정태3
,
김 한성4
,
홍 은수5*
1Master’s Course, Department of Civil and Environmental Engineering, KAIST
2Professor, Department of Civil and Environmental Engineering, KAIST
3Ph.D. Candidate, Department of Civil and Environmental Engineering, KAIST
4President, HBC Inc.
5Research Associate Professor, Department of Civil and Environmental Engineering, KAIST
1비회원, KAIST 건설 및 환경공학과 석사과정
2정회원, KAIST 건설 및 환경공학과 교수
3비회원, KAIST 건설 및 환경공학과 박사과정
4비회원, 주식회사 에이치비씨 대표이사
5비회원, KAIST 건설 및 환경공학과 연구부교수
* Corresponding Author
31 July 2018. pp. 717-729
PDF XML Citation
Abstract

Considering the stability of the ground in the process of excavation design is essential because there is a risk of basal heave due to the load of the surrounding ground during the vertical excavation. However, calculation of the factor of safety for basal heave should be performed with two-dimensional equation, and the equation cannot reflect three-dimensional shape of vertical excavation. In this study, an equation for factor of safety for the basal heave was proposed with considering the effect of three-dimensional shape. It is confirmed that the equation can more appropriately reflect the basal heave stability 3D circular vertical excavation than the existing equation. Using the equation proposed in this study, it is possible to derive an appropriate factor of safety according to the 3D excavation shape during the circular vertical shaft excavation.

Keywords
Circular vertical shaft
Basal heave
Factor of safety
3D effect
Numerical analysis

연약지반 수직구 굴착 중에는 주변 지반의 하중으로 인한 굴착면의 히빙이 발생할 위험이 있기 때문에 굴착 설계 시 지반 안정성에 대한 고려가 필수적이다. 그러나 연약지반 히빙 안전율 산정은 2차원 산정식으로 수행하여야 하므로 수직구의 3차원 형상을 고려하지 못하는 문제가 있다. 본 연구에서는 수직구 굴착 시 히빙 안전율에 대한 선행 연구를 보완하여 3차원 효과를 반영하는 히빙에 대한 안전율 식을 제안하였으며, 해당 식이 기존 식에 비해 3차원 원형 수직구 굴착에서의 히빙 안정성을 더 적절하게 반영할 수 있음을 확인하였다.

키워드
원형수직구
히빙
안전율
3차원 효과
수치해석
References
1
Aksoy, C.O. (2008), “Chemical injection application at tunnel service shaft to prevent ground settlement induced by groundwater drainage: A case study”, International Journal of Rock Mechanics and Mining Sciences, Vol. 45, No. 3, pp. 376-383.
10.1016/j.ijrmms.2007.06.005
2
Bjerrum, L., Eide, O. (1956), “Stability of strutted excavations in clay”, Geotechnique, Vol. 6, No. 1, pp. 32-47.
10.1680/geot.1956.6.1.32
3
Center for Utility Tunnel (2015), Development of core technology for urban small-diameter utility tunnel construction.
4
Hong, E.S., Cho, G.C., Baak, S., Jun, H.W. (2016), “Rapid construction technique development for vertical shafts of utility tunnels”, Proceedings of the KTA 2016 Annual Spring Conference, Seoul, pp. 129-130.
5
Kim, D.H., Lee, D.S., Kim, K.Y., Lee, Y.H., Lee, I.M. (2009), “Earth pressure acting on vertical circular shafts considering arching effects in c-φ soils: I. Theory”, Journal of Korean Tunnelling and Underground Space Association, Vol. 11, No. 2, pp. 117-129.
6
Kim, D.H., Lee, K.H., Lee, I.M. (2011), “Seepage-induced behavior of a circular vertical shaft”, Journal of Korean Tunnelling and Underground Space Association, Vol. 13, No. 6, pp. 431-450.
7
Kim, K.Y., Lee, D.S., Jeong, S.S. (2012), “Analysis of earth pressure acting on vertical circular shaft considering aching effect (I): a study on centrifuge model tests”, Journal of the Korean Geotechnical Society, Vol. 28, No. 2, pp. 23-31.
10.7843/kgs.2012.28.2.23
8
Shin, Y.W., Kim, S.S., Kim, Y.J. (2010), “Development of design charts for concrete lining in a circular shaft”, Journal of Korean Tunnelling and Underground Space Association, Vol. 12, No. 2, pp. 165-175.
9
Shin, Y.W., Park, T.S., Lee, I.K. (2005), “A method of estimating earth pressure on a shaft wall and ground settlement caused by excavation”, Proceedings of the KSCE Tunnel Committee Special Conference, pp. 151-167.
10
Shin, Y.W., Sagong, M. (2007), “A rational estimating method of the earth pressure on a shaft wall considering the shape ratio”, Journal of Korean Tunnelling and Underground Space Association, Vol. 9 No. 2, pp. 143-155.
11
Tan, Y., Wang, D. (2013), “Characteristics of a large-scale deep foundation pit excavated by the central- island technique in Shanghai soft clay. I: Bottom-up construction of the central cylindrical shaft”, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 139, No. 11, pp. 1875-1893.
10.1061/(ASCE)GT.1943-5606.000092810.1061/(ASCE)GT.1943-5606.0000929
12
Terzaghi, K., Peck, R. (1948), Soil mechanics in engineering practice, John Wile and Sons, New York.
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 : 20
  • No :4
  • Pages :717-729
  • Received Date : 2018-06-05
  • Revised Date : 2018-06-21
  • Accepted Date : 2018-06-26
  • DOI :https://doi.org/10.9711/KTAJ.2018.20.4.717
Journal Informaiton Journal of Korean Tunnelling and Underground Space Association Journal of Korean Tunnelling and Underground Space Association
Online Submission & Review System
  • NRF
  • KOFST
  • KISTI Current Status
  • KISTI Cited-by
  • crosscheck
  • orcid
  • open access
  • ccl
Journal Informaiton Journal Informaiton - close