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Seismic Behaviors of Concrete-Suction-Type Offshore Wind Turbine Supporting Structures Considering Soil-Structure Interaction

지반-구조물 상호작용을 고려한 콘크리트 석션식 해상풍력 지지구조물의 지진거동 특성

  • Lee, Jin Ho (Department of Ocean Engineering, Pukyong National Univ.) ;
  • Jin, Byeong-Moo (Daewoo Institute of Construction Technology, DAEWOO E&C) ;
  • Bae, Kyung-Tae (Daewoo Institute of Construction Technology, DAEWOO E&C)
  • Received : 2017.06.22
  • Accepted : 2017.07.25
  • Published : 2017.08.31

Abstract

In this study, characteristics of seismic behaviors of offshore wind turbine systems using concrete-suction-type supporting structures are investigated. Applying hydrodynamic pressure from the surrounding sea water and interaction forces from the underlying soil to the structural system which is composed of RNA, the tower, and the supporting structure, a governing equation of the system is derived and its earthquake responses are obtained. It can be observed from the analysis results that the responses are significantly influenced by soil-structure interaction because dynamic responses for higher natural vibration modes are increased due to the flexibility of soil. Therefore, the soil-structure interaction must be taken into consideration for accurate assessment of dynamic behaviors of offshore wind turbine systems using concrete-suction-type supporting structures.

본 연구에서는 콘크리트 석션식 지지구조물을 사용한 해상풍력발전시스템의 지진응답 해석을 수행하여 그 거동 특성을 파악한다. 전체 시스템을 RNA, 타워, 지지구조물로 구성된 구조계와 이에 접하고 있는 유체 및 지반의 부분구조로 분리하여 운동방정식을 유도한다. 구조계에 작용하는 유체의 동수압과 지반의 상호작용력을 산정하고, 이를 구조계의 운동방정식과 결합하여 전체 시스템의 지배방정식을 도출한 후, 이 방정식의 해를 구하여 해상풍력발전시스템의 지진응답을 계산한다. 해석 결과로부터 지반-구조물 상호작용은 콘크리트 석션식 지지구조물에 의해 지지된 해상풍력발전시스템의 지진응답을 크게 증가시킬 수 있음을 확인할 수 있다. 특히, 지반의 유연성으로 인해 시스템의 고차 고유모드 응답이 증가할 수 있으므로, 해상풍력발전시스템의 동적거동 산정 시에는 반드시 지반-구조물 상호작용의 효과를 고려하여야 할 것이다.

Keywords

References

  1. Choi, H.-C., Kim, D.-H., Kim, D.-M., Park, K.-K. (2010) Seismic Response Analysis of a MW Class Wind-Turbine Considering Applied Wind Loads, J. Comput. Struct. Eng. Inst. Korea, 23(2), pp.209-215.
  2. EESK, KICT (1997) The Research of Seismic Design Code(II), Ministry of Construction and Transportation.
  3. Kausel, E. (1974) Forced Vibrations of Circular Foundations on Layered Media, Research Report R74-11, Department of Civil Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts.
  4. Lee, J.H., Bae, K.T., Jin, B.M., Kim, J.K. (2013) Earthquake Response Analysis of an Offshore Wind Turbine Considering Effects of Geometric Nonlinearity of a Structure and Drag Force of Sea Water, EESK J. Earthq. Eng., 17, pp.257-269.
  5. Lee, J.H., Kim, J.K. (2015) Analysis of Threedimensional Earthquake Responses of a Floating Offshore Structure with an Axisymmetric Floating Structure, EESK J. Earthq. Eng., 19, pp.145-159.
  6. Lee, J.H., Lee, S., Kim, J.K. (2012) Earthquake Response Analysis of an Offshore Wind Turbine Considering Fluid-Structure-Soil Interaction, EESK J. Earthq. Eng., 16, pp.1-12.
  7. Spera, D.A. (2009) Wind Turbine Technology, Fundamental Concepts of Wind Turbine Engineering, 2nd Edition, ASME Press, Three Park Avenue, New York.