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2018 Vol.20, Issue 3 Preview Page
Behavior of wall and nearby tunnel due to deformation of strut of braced wall using laboratory model test

실내모형시험을 통한 흙막이벽체 버팀대 변형에 따른 흙막이벽체 및 인접터널의 거동

Sung Joo Ahn1
,
Sang Duk Lee2*
안 성주1
,
이 상덕2*
1Design Manager, Infra Structure Business Unit, Samsung C&T Corporation
2Professor, Dept. of Civil and Transportation Engineering, Ajou University
1정회원, 삼성물산 건설부문 인프라사업부 책임
2정회원, 아주대학교 건설교통시스템공학과 교수
* Corresponding Author
31 May 2018. pp. 593-608
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Abstract

If a problem occurs in the strut during the construction of the braced wall, they may cause excessive deformation of the braced wall. Therefore, in this study, the behavior of the braced wall and existing tunnel adjacent to excavation were investigated assuming that the support function of strut is lost during construction process. For this purpose, a series of model test was performed. As a result of the study, the earth pressure in the ground behind wall was rearranged due to the deformation of the braced wall, and the ground displacements caused the deformation of adjacent tunnels. When the struts located on the nearest side wall from the tunnel were removed, the deformation of the braced wall and the tunnel deformation were the largest. The magnitude of transferred earth pressure depended on the location of tunnel. The increase of the cover depth of tunnel from 0.65D to 2.65D caused the increase of the earth pressure by 25.6%. As the distance between braced wall and tunnel was increased from 0.5D to 1.0D, the transferred earth pressure increased by 16% on average. Horizontal displacements of braced wall by the removal of the strut tended to concentrate around the removed struts, and the horizontal displacement increased as the strut removal position is lowered. The tunnel displacement was maximum, when the cover depth of tunnel was 1.15D and the horizontal distance between braced wall and the side of tunnel was 0.5D. The minimal displacement occurred, when the cover depth of tunnel was 2.65D and the horizontal distance between braced wall and the side of tunnel was 1.0D. The difference between the maximum displacement and the minimum displacement was about 2 times, and the displacement was considered to be the largest when it was in the range of 1.15D to 1.65D and the horizontal distance of 0.5D.

Keywords
Braced wall
Adjacent construction
Deformed strut
Model test
Tunnel

흙막이벽체 시공 중 버팀대에 문제가 발생하여 변형되거나 제 기능을 상실하게 되면 흙막이벽체에 과다한 변형의 원인이 된다. 따라서 본 연구에서는 모형시험을 통해 시공 중 흙막이벽체의 버팀대 일부가 기능을 상실하게 되었을 때 흙막이벽체의 거동특성 및 배면에 인접한 터널의 거동을 파악하고자 하였다. 연구 결과, 흙막이벽체의 변형으로 인해 배면지반의 토압이 재배치되고 지표변위를 발생시켜 인접한 터널의 변형에 영향을 미쳤으며, 터널에서 가장 가까운 측벽에 위치한 버팀대를 제거하였을 때 흙막이벽체 변형 및 터널변형이 가장 크게 나타났다. 터널의 위치에 따른 평균 전이토압은 터널 심도가 0.65D에서 2.65D로 깊어짐에 따라 평균 25.6% 증가하였으며, 흙막이벽체와 터널과의 이격거리가 0.5D에서 1.0D로 증가함에 따라 전이토압이 평균 16% 증가하였다. 버팀대 제거에 따른 흙막이벽체의 수평변위는 제거되는 버팀대 부근에 집중되는 경향을 보였으며 버팀대 제거위치가 하부로 내려갈수록 수평변위는 비선형적으로 증가하는 것으로 나타났다. 터널 내공변위는 토피고 1.15D, 수평거리 0.5D일 때 최대 내공변위가 발생하였고, 토피고 2.65D, 수평거리 1.0D에서 최소 내공변위가 발생하였다. 가상파괴면이 터널의 중심부를 통과하는 범위인 토피고 1.15~1.65D, 수평거리 0.5D에서 터널의 내공변위가 크게 증가하는 것으로 검토되었으며, 최대 내공변위와 최소 내공변위의 차이는 약 2배 정도 발생하였다.

키워드
흙막이벽체
근접시공
버팀대 기능상실
실내모형실험
터널
References
1
Back, S.H. (2002), A behavior of braced wall and adjacent ground with the preloading and wall stiffness, Master Thesis, Ajou University, pp. 31-33.
2
Choi, Y.J., Park, B.S., Lee, S.D. (2013), “A study on the behavior of the adjacent tunnel due to the deformation of bracing”, Procceedings of the KTA 2013 Fall Symposium, November 01, 2013, pp. 67-70.
3
Choi, Y.J. (2013), Behavior of a tunnel adjacent to the cut-off wall due to the deformation of bracing, Master Thesis, Ajou University, pp. 31-35.
4
Clough, G.W., Smith, E.M., Sweeney, B.P. (1989), “Movement control of excavation support systems by iterative design”, Proceedings of the ASCE Foundation Engineering: Current Principles and Practices, 2, pp. 869-884.
5
Duddeck, H., Erdmann, J. (1985), “Structural design models for tunnels in soft soil”, Underground Space, Vol. 9, Pergamon Press, pp. 246-259.
6
Hwang, R. N., Duann, S.W., Cheng, K.H., Chen, C.H. (2011), “Damages to metro tunnels due to adjacent excavations”, Proceedings of the International Symposium on Backward Problems in Geotechnical Engineering, TC302, Osaka 2011, pp. 83-88.
7
Kim, I., Lee, S.D. (2007), “behavior of tunnel under the influence of pre-loading on braced wall during the adjacent ground excavation”, Journal of Korean Tunnelling and Underground Space Association, Vol. 9, No. 4 pp. 331-341.
8
Lee, J.M., Lee, S.D. (2010), “Behavior of building lower part passage tunnel due to adjacent ground excavation”, Tunnel and Underground Space, Vol. 20, No. 5 pp. 369-377.
9
Lee, S.D. (2014), Soil Mechanics, CIR, Seoul, pp. 353-354, 388-396.
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 :3
  • Pages :593-608
  • Received Date : 2018-02-19
  • Revised Date : 2018-03-02
  • Accepted Date : 2018-03-21
  • DOI :https://doi.org/10.9711/KTAJ.2018.20.3.593
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