Settlement Characteristics of Soft Ground Applying the Suction Drain Method

Sang-Jae Han; Han-Kyu Yoo; Byung-Il Kim; Soo-Sam Kim

doi:10.7843/kgs.2013.29.3.15

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2013 Vol.29, Issue 3 Preview Page Next Page

Settlement Characteristics of Soft Ground Applying the Suction Drain Method 석션드레인공법을 적용한 연약지반의 침하 특성

31 March 2013. pp. 15-27

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Abstract

A vacuum pressure method has been developed to solve many problems in the conventional surcharge method such as embankments, and its application has increased in the country. Recently, to control target settlements in the field, there have been many studies on the comparison of settlements between vacuum pressure method and surcharge load method in the same conditions. In this study, the settlement characteristics of soil subjected to vacuum pressure and surcharge pressure are discussed. The results indicate that if vacuum pressure is applied to the improvement of soft ground, there will be inward lateral displacement and the vacuum pressure will induce generally less settlement than a surcharge load of the same magnitude. The range of settlement reduction ratio is 0.54～0.67 based on Hooke's law, 0.91 based on field cases, 0.81 based on laboratory oedometer tests, 0.75 based on the theory of elasticity and coefficient of volumetric compressibility and 0.77～0.93 in its recent applications to the thick soft ground.

Keywords

Suction drain method

Vacuum consolidation

Settlement reduction ratio

Soft ground

기존 성토재하 방식의 연약지반 개량공법에서 제기된 여러 가지 문제에 의해 진공압 재하방식의 개량공법이 개발되었으며, 국내 적용사례가 증가하고 있다. 현장에서의 침하관리시 동일한 하중을 재하하였을 경우의 진공압재하공법과 성토재하공법에 대한 침하량 비교 연구가 진행되어 왔다. 본 연구에서는 두 공법의 발생침하량에 관한 이론 및 사례 연구를 수행하였다. 그 결과 연약지반 개량을 위해 진공압이 적용되면 내향의 수평변위가 발생하고 동일한 하중재하대비 침하량이 감소하였다. Hooke의 탄성이론을 바탕으로 한 경우 0.54～0.67, 국내 설계기준에서는 0.50～0.75, 과거 국내 시공사례를 바탕으로 한 경우 0.91, 실내시험을 바탕으로 한 경우 0.81, 탄성론과 체적압축계수법을 바탕으로 한 경우 0.75, 최근 국내 대심도 시공 사례의 경우 0.77～0.93의 범위를 보이는 것으로 나타났다.

References

1.An dong uk (2010), “Numerical evaluation of soft ground response under application of the individual vacuum pressure”, Ph.D thesis. Hanyang university, pp.15-62, 152-218.

2.Chai, J. C. Carter, J. P., and Hayashi, S. (2005) “Ground deformation induced by vacuum consolidation.” Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 131, 1552-1561.

3.Daewoo E&C. (2009), “Busan Newport Ungdong 1st phase porthinterland (3rd zone) - Structure and hydraulic calculating report”, pp. 7-77-103

4.Daewoo E&C. (2011), “Busan Newport Ungdong 1st phase porthinterland (3rd zone) - Ground improvement finishing report”, pp.8-35.

5.Hansbo, S. (1981) “Consolidation of fine-grained soils by prefabricated drains”, Proc. 10th Int. Conf. Soil Mech. Found. Eng., Stockholm, Sweden Vol.3, paper.12/22, pp.677-682.

6.Hird, C. C., Pyrah, I. C., and Russell, D. (1992), “Finite element modelling of vertical drain beneath embankments on soft ground”, Geotechnique Vol.42, No.3, pp.499-511.

7.Imai Goro (2005), “For the Further Development of Vacuum-Induced Consolidation Method”, 日本土木學會論文集 No.798/Ⅵ-68, pp.1-16.

8.Kim, B. I., Kim, D. H., Kim, S. S., and Han, S. J. (2009), “Consolidation characteristics of soft ground in suction drain method”, J. of KSCE, Vol.29, No.6, pp.287-294.

9.Kim, K. N. (2008), “Analysis of consolidation settlement considering hardening zone in suction board drain method”, Ph.D thesis. Hanyang university, pp.11-30.

10.Liu, X. (1996), “Application and Experience of Vacuum Preloading Method”, Proc. of Int. Workshop on Technology Transfer for Vacuum- Induced Consolidation, pp.47-69.

11.Kang, M. S., Song, Y. J., Kim, S. S., and Lee, S. I. (2007), “The Analysis of efficiency of suction drain method by step vacuum pressure”, Proceedings of the Seventeenth International Offshore and Polar Engineering Conference, pp.1287-1292.

12.Ihm, C. W. and Masse, F. (2002), “Successful application of Menard vacuum consolidationTM method to Nakdong river soft clay in Kimhae, South Korea”, Proc. 4th International Conference on Ground Improvement Techniques, pp.26-28.

13.Ministry of Maritime and Fisheries (2005), “Harbor and fishing port design criteria”, Vol.1, Chap.4-7, pp.596.

Information

Publisher :The Korean Geotechnical Society
Publisher(Ko) :한국지반공학회
Journal Title :Journal of the Korean Geotechnical Society
Journal Title(Ko) :한국지반공학회 논문집
Volume : 29
No :3
Pages :15-27
Received Date : 2012-03-28
Accepted Date : 2013-02-18
DOI :https://doi.org/10.7843/kgs.2013.29.3.15

Journal of the Korean Geotechnical Society ISSN:1229-2427(Print) 2288-646X(Online) 한국지반공학회 논문집

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