All Issue

2018 Vol.17, Issue 3

Research Article

Numerical Analysis on the Behavior of Revetment Reinforced by Sand Compaction Pile According to Area Replacement Ratio

수치해석을 이용한 모래다짐말뚝 치환율에 따른 호안 구조물의 거동 분석

Byoung-Il Kim1
,
Tae-Ho Bong2
,
Jin-Tae Han3
,
Young-Eun Jang4*
김 병일1
,
봉 태호2
,
한 진태3
,
장 영은4*
1Nonmember, Professor, Dept of Civil and Environmental Engineering, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi-do, Republic of Korea
2Nonmember, Research Professor, Institute of Construction and Environmental Engineering, Seoul Univ., San 56-1 Sillim, Gwanak, Seoul, Republic of Korea
3Member, Research Fellow, Center of Seismic Safety Research, Korea Institute of Civil Engineering & Building Technology, 238 Goyangdae-Ro, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do, Republic of Korea
4Member, Researcher, UEE Research Institute, UNIST, 50 UNIST-gil, Ulsan 44919, Republic of Korea
* Corresponding Author
30 September 2018. pp. 1-8
PDF XML Citation
Abstract

Sand compaction pile (SCP) is a ground improvement method which is used to secure the stability of the soft ground by using a type of replacement pile filled with coarse grained material. The behavior characteristics of the SCP, which is frequently used for improving both the onshore and offshore ground, is governed by the ground condition, the installation method, and replacement ratio. Therefore, the stability of the SCP in terms of the bearing capacity and displacement needs to be evaluated considering both the design values and in-situ conditions of construction site. In this study, numerical analysis is carried out based on the conditions of 00 revetment construction site in South Korea where unexpected displacement occurred during construction of SCP. Based on the analysis results, the displacement of the revetment structure according to the replacement ratio of the SCP was compared to the result calculated from design formulas. The results showed that the lateral displacement can be exceeded the reference value from proposed criteria regardless of increased replacement ratio of SPC. It is also confirmed that the behavior of the structure according to the replacement ratio of SPC in not reflected in the existing calculation methods. Therefore, the stability of the SCP composite ground should be examined through the site inspection after the SCP construction.

Keywords
Sand compaction pile
SCP method
Area replacement ratio
Revetment structure
SCP composite ground

모래다짐말뚝은 연약 지반에 조립질 재료로 채워진 말뚝 형태의 치환재료 시공을 통해 지반의 안정성을 확보하기 위한 목적으로 활용되는 지반개량 공법이다. 육상 및 해상의 연약지반 개량을 목적으로 꾸준히 사용되고 있는 모래다짐말뚝의 거동 특성은 지반 조건, 설치 방법 및 시공 형태에 따른 치환율 등에 의해 결정된다. 그러므로 모래다짐말뚝의 지지력 및 거동특성에 따른 안정성을 확보하기 위해서는 기존의 설계 식뿐만 아니라 시공 현장의 특성 및 영향 인자 등을 고려해 종합적으로 검토되어야 할 필요가 있다. 본 논문에서는 모래다짐말뚝 시공 중 예상치 못한 말뚝의 과다 변위가 발생한 국내 현장의 호안 축조 현장조건을 바탕으로 수치해석을 수행하고, 모래다짐말뚝의 치환율에 따른 지반의 변위 특성을 기존 제안식과 비교하였다. 해석결과 모래다짐말뚝의 치환율이 증가하여도 호안 구조물의 수평변위가 교대 말뚝 변위의 기준값을 초과할 수 있는 것으로 나타났으며, 이러한 지반 치환율에 따른 구조물의 거동 특성은 기존의 모래다짐말뚝 지지력 산정식에는 반영되지 못함을 확인하였다. 그러므로 모래다짐말뚝 시공 후에는 현장 시공성 확인을 병행하여 SCP 복합지반의 안정성을 검토해야 할 것으로 나타났다.

References
1
Barksdale, R. D. and Takefumi, T. (1991), “Design, Construction and Testing of Sand Compaction Piles”, Deep Foundation Improvements : Design, Construction and Testing, ASTM STP 1089, pp.4-18.
10.1520/STP25047S
2
Barksdale, R. D. and Bachus, R. C. (1983), Design and construction of Stone Columns, Report No. FHWA/RD-83/026, National Technical Information Service.
3
Bozozuk, M. (1978), Bridge Foundations Move, Transportation Research Record No. 678, Transportation Research Board, Washington DC, pp.17-21.
4
Greenwood, D. A. (1970), “Mechanical Improvement of Soils Below Ground Surface”, Proc. of Ground Engineering Conference, Institute of Civil Engineering, pp.9-20.
5
Hansbo, S. (1994), Foundation Engineering, Development in Geotechnical Engineering, Elsevier, Amsterdam, pp.450-455.
6
Hughes, J. M. O., Withers, N. J., and Greenwood, D. A. (1975), “A Field Trial of the Reinforcing Effect of a Stone Column in Soil”, Geotechnique, Vol.25, No.1, pp.31-44.
10.1680/geot.1975.25.1.31
7
Kim, J. K. (2003), Load transfer characteristrics of sand compaction piles in soft ground, Ph.D Thesis, Yonsei University, pp.20-23.
8
Kitazume, M. (2005). The sand compaction pile method, Taylor and Francis, London.
10.1201/9781439824696
9
Kim, B. I. and Lee S. H. (2004), “Comparison of Bearing Capacity Characteristics of Sand and Gravel Compaction Pile Treated Ground”, KSCE Journal of Civil Engineering, Vol.9, No.3, pp.197-203.
10.1007/BF02829050
10
Kim, B. I., Cho, S. M., Kim, J. H. and Kim, S. R. (2015), Soft Ground Improvement Method, CIR Publishing Co. pp.239-283.
11
Madhav, M. R. and Vitkar, P. P. (1978), “Strip footing on weak clay stabilized with a granular trench or pile”, Canadian Geotechnical Journal, Vol.15, pp.605-609.
10.1139/t78-066
12
Mori, H. (1979), “Some Case Records of Stability and Settlement of Embankment of the Soft Ground”, Proc. of 6th Asian Regional Conference on Soil Mechanics and Foundation Engineering, Vol.2, pp.169-189.
13
Murayama. S. (1962), “Considerations of vibro-compozer method for application to cohesive ground”, Journal of Construction Machinery, No.150, pp.10-15(in Japanese).
14
Wong, H. Y. (1975). Vibroflotation - its effect on weak cohesive soils, Civil Engineering, No.824, pp.44-67.
15
Vesic, A. S. (1972), “Expansion of cavities in infinite soil mass” Journal of soil mechanics and foundations division, Vol.98, No.3, pp.265-290.
Information
  • Publisher :Korean Geosythetics Society
  • Publisher(Ko) :한국지반신소재학회
  • Journal Title :Journal of the Korean Geosynthetics Society
  • Journal Title(Ko) :한국지반신소재학회 논문집
  • Volume : 17
  • No :3
  • Pages :1-8
  • Received Date : 2018-07-13
  • Revised Date : 2018-08-23
  • Accepted Date : 2018-09-03
  • DOI :https://doi.org/10.12814/jkgss.2018.17.3.001
Journal Informaiton Journal of the Korean Geosynthetics Society Journal of the Korean Geosynthetics Society
  • NRF
  • KOFST
  • KISTI Current Status
  • KISTI Cited-by
  • crosscheck
  • orcid
  • open access
  • ccl
Journal Informaiton Journal Informaiton - close