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A Study for Safety Management on the Basis of Lateral Displacement Rates of Anchored In-situ Walls by Collapse Case Histories

붕괴 사례를 통한 앵커지지 가설흙막이벽체의 수평변위속도에 의한 안전관리 연구

  • Received : 2018.08.21
  • Accepted : 2018.09.25
  • Published : 2018.09.30

Abstract

Purpose: The objective of this study is to present a reasonable safety management of the anchored in-situ wall systems constructed in the ground conditions consisting of multi-layered soils underlain by bedrocks in the urban area of Korea. Method: Field measurements collected from collapse case histories with deep excavations were analyzed for the safety management of the wall systems supported by the earth anchors in terms of lateral displacement rates. Results: The average maximum lateral displacement rate in a collapsed zone of the in-situ wall significantly increased upon the completion of the excavation. Particularly, the collapse of the in-situ wall system due to the sliding occurring along the discontinuities of the rock produced a considerably large lateral displacement rate over a relatively short period. Conclusion: For predicting and preventing the collapse of the wall system during or after the excavation work, the utilization of the safety management criteria of the in-situ wall system by the lateral displacement rate was found to be much more reasonable in judging the safety of earthworks than the application of the quantitative management criteria which have been commonly used in the excavation sites.

연구목적: 본 연구는 국내 도심지 굴착시 흔히 마주치는 암반을 포함한 다층토 지반에서 앵커지지 흙막이 구조물의 합리적인 안전관리방법에 대해 서술하는 것을 목적으로 한다. 연구방법: 흙막이 굴착공사의 붕괴사례 현장으로부터 수집한 현장 계측자료를 바탕으로 깊은 굴착시 앵커지지 흙막이벽체의 수평변위속도 관점에서 흙막이 구조물의 안전관리방법에 대해 접근하였다. 연구결과: 붕괴구간의 흙막이벽체 평균 최대수평변위속도는 굴토완료 이후에 뚜렷하게 증가하는 추세를 보였다. 특히, 암반 불연속면을 따라 발생하는 슬라이딩에 의한 흙막이 구조물 붕괴는 비교적 짧은 시간에 상당히 큰 변위속도를 나타냈다. 결론: 본 연구를 통해 굴착공사중 흙막이 구조물 붕괴 사고를 사전에 예측하고 예방하기 위해 국내 현장에서 일반적으로 적용되어온 수평변위에 의한 정량적인 관리기준보다는 수평 변위속도에 의한 안전관리기준의 활용은 흙막이 굴착공사의 안전성을 판단하는데 훨씬 합리적인 것으로 나타났다.

Keywords

References

  1. Kim, D.J. (1998). Design of In-situ Wall System and Instrumentation, Saeron Press, Seoul, Korea, pp.320-337.
  2. Kim, M.S. (2012). The Role of Field Monitoring to Prevent Failure During Ground Excavation Works, M.S. Thesis, Chung-ang University, Seoul, Korea, pp.4-81.
  3. Yang, G.S. (1996). Analysis of Adjacent Ground Movements for Deep Excavations in Urban Areas, Ph.D. Thesis, Seoul National University, Seoul, Korea, pp.23-66.
  4. Lee, D.W., Kim, J.H., Lee, J.Y., and Chun, B.S. (2007). "A Study of Behavior on Earth Retaining Wall and Soil Pressure in Urban Area Excavation", Proceedings of Korean Geo-Environmental Society, Korea, pp.259-256.
  5. Lee, C.K. and Jeon, S.K. (1993). "Earth Pressure Distribution on Retention Walls in the Excavation of Multi-Layered Ground", Journal of The Korean Geotechnical Society, Vol.9, No.1, Korea, pp.59-68.
  6. Korean Geotechnical Society (1992). Excavations and Earth Retaining Structures, Geotechnical Engineering Series, Volume 3, Goomibook Press, Seoul, Korea, pp.364-370.
  7. Hong, W.P. and Yun, J.M. (1995). "A Study on the Stability of Anchored Retention Walls for Underground Excavation", Journal of The Korean Society of Civil Engineers, Vol.15, No.4, Korea, pp.991-1002.
  8. Clough, G.W. and O'Rourke, T.D. (1990). "Construction Induced Movements of In Situ Walls", Specialty Conference on Design and Performance of Earth Retaining Structures, Lambe, P. C. & Hansen, L. A. ed., New York, US, pp.439-470.
  9. Goldberg, D.T., Jaworski, W.E., and Gordon, M.D. (1976). Lateral support Systems and Underpinning, Report FHWA-RD-75-128, Vol. 1, Federal Highway Administration, US, pp.1-28.
  10. Hashashi, Y.M.A. and Whittle, A.J. (1996). "Ground Movement Prediction for Deep Excavations in Soft Clay", Journal of Geotechnical Engineering, Vol.122, No.6, US, pp.474-486. https://doi.org/10.1061/(ASCE)0733-9410(1996)122:6(474)
  11. Mana, A.I. and Clough, G.W. (1981). "Prediction of Movements for Braced Cuts in Clay", Journal of the Geotechnical Engineering Division, Vol.107, Issue 6, US, pp.759-777.
  12. NAVFAC (1982). DM-7.2, US, pp. 13-20.
  13. Ou, C.Y., Hsieh P.G., and Chiou, D.C. (1993). "Characteristics of Ground Surface Settlement during Excavation", Canadian Geotechnical Journal, Vol.30, No.5, Canada, pp.758-767. https://doi.org/10.1139/t93-068
  14. Peck, R.B. (1969). "Deep Excavation and Tunneling in Soft Ground", Proceedings of the 7th International Conference on Soil Mechanics and Foundation Engineering, State-of-the-Art Report, Mexico, pp.259-290.
  15. Yoo, C.S. (2001). "Behavior of Braced and Anchored Walls in Soils Overlying Rock", Journal of Geotechnical and Geoenvironmental Engineering, Vol.127, No.3, US, pp.225-233. https://doi.org/10.1061/(ASCE)1090-0241(2001)127:3(225)