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Evaluation of Pile-Ground Interaction Models of Wind Turbine with Twisted Tripod Support Structure for Seismic Safety Analysis

지진 안전도 해석을 위한 Twisted Tripod 지지 구조를 갖는 풍력발전기의 말뚝-지반 상호작용 모델 평가

  • Park, Kwang-yeun (Institute of Construction and Environmental Engineering, Seoul National University) ;
  • Park, Wonsuk (Department of Civil Engineering, Mokpo National University)
  • 박광연 (서울대학교 건설환경종합연구소) ;
  • 박원석 (목포대학교 토목공학과)
  • Received : 2017.12.26
  • Accepted : 2018.02.09
  • Published : 2018.02.28

Abstract

The seismic response, the natural frequencies and the mode shapes of an offshore wind turbine with twisted tripod substructure subject to various pile-ground interactions are discussed in this paper. The acceleration responses of the tower head by four historical earthquakes are presented as the seismic response, while the other loads are assumed as ambient loads. For the pile-ground interactions, the fixed, linear and nonlinear models are employed to simulate the interactions and the p-y, t-z and Q-z curves are utilized for the linear and nonlinear models. The curves are designed for stiff, medium and soft clays, and thus, the seven types of the pile-ground interactions are used to compare the seismic response, the acceleration of the tower head. The mode shapes are similar to each other for all types of pile-ground interactions. The natural frequencies, however, are almost same for the three clay types of the linear model, while the natural frequency of the fixed support model is quite different from that of the linear interaction model. The wind turbine with the fixed support model has the biggest magnitude of acceleration. In addition, the nonlinear model is more sensitive to the stiffness of clay than the linear pile-ground interaction model.

Keywords

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