Journal of Korean Society of Steel Construction (한국강구조학회 논문집)

Korean Society of Steel Construction (한국강구조학회)
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New Development of Hybrid Concrete Support Structure with Driven Piles for Offshore Wind Turbines

하이브리드 해상풍력 파일 기초 콘크리트 지지구조(MCF) 개발

  • Kim, Hyun Gi (Dept. of Civil and Environmental System Engineering, Konkuk University) ;
  • Kim, Bum Jun (Dept. of Civil and Environmental System Engineering, Konkuk University) ;
  • Kim, Ki Du (Dept. of Civil and Environmental System Engineering, Konkuk University)
  • 김현기 (건국대학교 사회환경시스템공학과) ;
  • 김범준 (건국대학교 사회환경시스템공학과) ;
  • 김기두 (건국대학교 사회환경시스템공학과)
  • Received : 2013.04.30
  • Accepted : 2013.06.11
  • Published : 2013.06.27
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Abstract

This paper proposes a new hybrid support structure by the driven piles which removes disadvantages of the existing type of support structure for offshore wind turbines. The hybrid type of support structure is combined with concrete cone and steel shaft, and is supported not only by gravity type foundations but also by driven piles. For three dimensional analysis of the huge and thick concrete structure, a solid-shell element that is capable of exact modeling and node interpolations of stresses is developed. By applying wave theory of stream function and solid-shell element in XSEA simulation software for fixed offshore wind turbines, a quasi-static analysis and natural frequency analysis of proposed support structure are performed with the environmental condition on Southwest Coast in Korea. In the result, lateral displacement is not exceed allowable displacement and a superiority of dynamic behavior of new hybrid support structure is validated by natural frequency analysis. Consequently, the hybrid support structure presented in this study has a structural stability enough to be applied on real-site condition in Korea. The optimized structures based on the preliminary design concept resulted in an efficient structure, which reasonably reduces fabrication costs.

기존 해상풍력발전 지지구조물의 단점을 보완한 신형식의 파일 기초 하이브리드 지지구조물을 본 연구에서 제안하였다. 이 지지구조는 콘크리트 자중을 이용한 중력식 기초의 개념으로부터 수정되어 4개의 파일로 지지되며, 강재 샤프트와 원추형 콘크리트가 결합된 하이브리드 형식이다. 규모가 크고 두꺼운 콘크리트의 3차원 해석을 위해, 정확한 기하형상 모델링과 응력의 절점 보간이 가능한 솔리드-쉘 입체요소를 개발하였다. 해양구조물 전용 유한요소 프로그램인 XSEA에 탑재된 솔리드-쉘 요소와 Stream Function 파랑 이론을 적용하여, 제안한 하이브리드 지지구조물에 대해 서남해안 지역의 환경조건을 적용한 준정적 해석 및 고유진동수 해석을 실시하였다. 해석결과, 수평변위가 허용변위 이내로 나타났고, 고유진동수 해석을 통해 하이브리드 구조형식의 동적거동에 대한 우수성을 입증하였다. 결과적으로, 파일지지 하이브리드 지지구조물은 우리나라 서남해안 지역과 같이 연약지반에 적용 할 수 있는 충분한 안정성을 가진 것으로 평가 되었고, 각 부재에 대한 최적화 연구를 통해 경제성 확보가 가능한 것으로 검토되었다.

Keywords

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  2. Seismic Analysis for Multi-pile Concrete Foundation in 5MW Class Offshore Wind Turbine vol.29, pp.3, 2016, https://doi.org/10.7734/COSEIK.2016.29.3.209
  3. Three-dimensional Analysis of Prestressed Concrete Offshore Wind Turbine Structure Under Environmental and 5-MW Turbine Loads pp.1993-5048, 2018, https://doi.org/10.1007/s11804-018-0021-9
  4. Analysis of Piled Concrete Foundation for a 3-MW Class Offshore Wind Turbine along the Southwest Coast in Korea vol.8, pp.3, 2013, https://doi.org/10.3390/jmse8030215
  5. Design Optimization of Conical Concrete Support Structure for Offshore Wind Turbine vol.13, pp.18, 2013, https://doi.org/10.3390/en13184876