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2013 Vol.29, Issue 11 Preview Page
Horizontal Bearing Behavior of Group Suction Piles by Numerical Analysis

수치해석을 이용한 그룹형 석션파일의 수평방향 지지거동 분석

Ju-Hyung Lee1
,
Si-Hoon Lee2*
,
Sung-Ryul Kim3
이 주형1
,
이 시훈2*
,
김 성렬3
1Senior Researcher, Geotechnical Engrg. Research Division, Korea Institute of Construction Technology
2Graduate Student, Dept. of Civil Engrg., Dong-A Univ.
3Associate Prof., Dept. of Civil Engrg., Dong-A Univ.
1한국건설기술연구원 Geo-인프라연구실 수석연구원
2동아대학교 토목공학과 박사수료
3동아대학교 토목공학과 부교수
*교신저자. *Corresponding Author. 
30 November 2013. pp. 119-127
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Abstract

Recently, several researches on the development of new economical foundation types have been performed to support floating structures as many offshore structures have been constructed. This study focused on the evaluation of bearing capacity of group suction piles, which are connected by a concrete pile cap. The offshore floating structures are mainly subjected to horizontal loading, so the horizontal bearing capacities of the group suction piles were analyzed by performing 3-dimensional finite element analyses. The group suction piles are expected to behave as a rigid pile due to its shallow embedded depth. Therefore, the detailed soil modeling was necessary to simulate the bearing behavior of soils under low confining pressure. The modulus and the strength of soils were modelled to increase with effective confining pressure in soils. For the parametric study, the center-to-center spacing between piles was varied and two soil types of clay and sands were applied. The analyses results showed that the yielding load of the group pile increased with the increase of the pile spacing and the yielding load of the group piles with 5D spacing was about 3 times larger than that of the single pile with free rotation.

Keywords
Suction pile
Group pile
Bearing capacity
Geosynthetics
Numerical analysis
Floating structure

최근 해양구조물의 건설이 활발해짐에 따라 해상 부유식 구조체를 경제적으로 지지할 수 있는 새로운 기초형식을 개발하려는 연구가 이루어지고 있다. 본 연구에서는 기존의 대구경 단일형 석션파일 대신에 다수의 중구경 석션파일을 콘크리트 파일캡으로 결합한 그룹형 석션파일 형식에 대하여 연구하였다. 해상 부유식 구조체에 사용되는 기초의 경우 수평방향 하중이 지배적이므로 그룹형 석션파일의 수평방향 지지거동을 3차원 유한요소 해석을 통해 분석하였다. 그룹형 석션파일은 근입깊이가 얕아서 강체기초 거동을 하게 되므로 수평방향 거동을 분석할 때 지표면 부근의 낮은 구속압을 받는 지반의 정밀한 거동 모사가 필요하다. 이를 위하여, 탄성계수, 지반강도 등을 지반 구속압에 따라 증가되도록 모델링하였다. 해석조건은 석션파일 중심간 거리, 그리고 사질토와 점성토의 지반조건 등을 변화시키며 변수연구를 수행하였다. 그 결과, 석션파일 사이의 간격이 증가함에 따라 점차 항복하중이 증가하였으며, 그룹형 석션파일의 항복하중은 S/D=5인 경우 회전을 허용한 단일형 석션파일 항복하중의 약 3배인 것으로 나타났다.

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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 :11
  • Pages :119-127
  • Received Date : 2013-08-18
  • Revised Date : 2013-11-12
  • Accepted Date : 2013-11-19
  • DOI :https://doi.org/10.7843/kgs.2013.29.11.119
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