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2025 Vol.41, Issue 4 Preview Page
Evaluation of Geotechnical Design for Suction Anchor Installation in Clay for Floating Offshore Wind Turbines

점토지반에서 부유식 해상풍력 석션앵커의 설치 시 지반설계 평가

Woo-Young Kim1
,
Na-Young Jung2*
,
Won-Hyo Lee3
,
Dae-Hwan Kim4
,
Tae-Hyung Kim5
김 우영1
,
정 나영2*
,
이 원효3
,
김 대환4
,
김 태형5
1Member, M.S. Candidate, Dept. of Civil Engineering, National Korea Maritime and Ocean Univ.
2Member, Ph.D. Candidate, Dept. of Civil Engineering, National Korea Maritime and Ocean Univ.
3Member, Ph.D. Candidate, Dept. of Civil Engineering, National Korea Maritime and Ocean Univ.
4Member, Ph.D. Candidate, Dept. of Civil Engineering, National Korea Maritime and Ocean Univ.
5Member, Prof., Dept. of Civil Engineering, National Korea Maritime and Ocean Univ.
1정회원, 국립한국해양대학교 토목공학과 석사과정
2정회원, 국립한국해양대학교 토목공학과 박사과정
3정회원, 국립한국해양대학교 토목공학과 박사과정
4정회원, 국립한국해양대학교 토목공학과 박사과정
5정회원, 국립한국해양대학교 토목공학과 교수
*Corresponding Author
31 August 2025. pp. 77-90
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Abstract

This study evaluates the geotechnical design of suction anchors for floating offshore wind turbines in clayey soils. It addresses key aspects such as anchor touchdown, penetration by self-weight and suction, and reinstallation considerations. The allowable excess pore pressure at each depth, based on anchor penetration, is determined using the soil’s lower-bound shear strength. During suction-assisted penetration, suction pressure must not exceed cavitation pressure, particularly in shallow soils. Reinstallation should occur within one day of retrieval, considering clay sensitivity to lateral shear. Although clay has greater erosion resistance than sandy soils, scour and trenching will eventually develop and must be incorporated into the design. Anchor tilt and misorientation should remain within recommended limits. When the seabed slope exceeds 5°, tilt increases and requires review. Anchor length should be determined with consideration of slope, alignment errors, scour, and ground heave.

Keywords
Clayey ground
Floating offshore wind turbine
Geotechnical design
Installation
Suction anchor

본 연구는 점토지반에 부유식 해상풍력 석션앵커를 설치하는 것에 대한 지반설계 평가 연구를 수행하였다. 석션앵커 착지, 자중에 의한 관입, 부압에 의한 관입, 재설치 시 고려해야 하는 사항을 검토하였다. 연구 결과, 앵커 착지 후 관입깊이에 따른 지반 깊이별 허용 과압은 지반의 전단강도 하한값을 이용하여 결정한다. 부압을 이용한 앵커 관입 시 얕은깊이 지반에서 허용 부압이 공동압력을 초과하지 않도록 해야 한다. 앵커 재설치는 앵커가 해저에서 회수된 후 1일 이내에 재설치가 필요하고 앵커의 측면전단에 대해 점토의 예민비를 고려해야 한다. 점토 지반은 침식 저항성이 모래질 퇴적지반에 비해 크나 진행 속도가 느릴 뿐이며, 궁극적으로 세굴 및 트렌치는 발생하므로 설계에서 고려해야 한다. 앵커의 수직도와 회전오차는 권장기준에서 제시한 허용기준 내에 설치가 필요하다. 해저면 경사가 5°를 초과하면 수직도 오차도 증가하므로 추가 검토가 필요하다. 해저면 경사와 앵커 수직도 및 회전오차, 세굴, 앵커 내부의 지반 융기 높이 등을 고려하여 적정 앵커 길이 산정이 필요하다.

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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 : 41
  • No :4
  • Pages :77-90
  • Received Date : 2025-06-23
  • Revised Date : 2025-07-25
  • Accepted Date : 2025-07-27
  • DOI :https://doi.org/10.7843/kgs.2025.41.4.77
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