Journal of the Korean GEO-environmental Society (한국지반환경공학회 논문집)

Korean Geo-Environmental Society (한국지반환경공학회)
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Stiffness of Bucket Foundation in Sand

사질토 지반에 설치된 버킷기초의 강성

  • Park, Jeongseon (Korea Hydro & Nuclear Power Central Research Institute (KHNP-CRI)) ;
  • Park, Duhee (Department of Civil and Environmental Engineering, Hanyang University) ;
  • Yoon, Sewoong (Department of Civil and Environmental Engineering, Hanyang University) ;
  • Jang, Hwasup (Research center, Korea Register of Shipping) ;
  • Yoon, Jinam (Department of Civil and Environmental Engineering, Hanyang University)
  • Received : 2017.06.05
  • Accepted : 2017.07.19
  • Published : 2017.08.01
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Abstract

To perform an integrated load analysis carried out to evaluate the stability evaluation of wind turbine generators, the six degree-of-freedom stiffness matrix of foundation, which describes relationships between loads and displacement, is needed. Since the foundation stiffness should accurately reflect the shape of foundation and the condition of soil, it is necessary to calculate the stiffness of the bucket foundation that considers the elasto-plastic behavior of the soil. In this study, finite element analyses were performed for a range of soils and shapes of bucket foundations to estimate the foundation stiffness. Normalized stiffness curves are developed from respective numerical simulations. Proposed results are considered to be useful because they can be directly applied in the design.

풍력발전기의 안정성 평가를 위해 수행하는 통합하중해석에서 기초는 하중과 변위의 관계로 정의되는 기초강성을 입력하여 적용이 가능하다. 이때 기초의 형상과 지반의 조건이 정확하게 반영된 기초의 강성이 적용되어야 하므로, 지반의 탄소성 거동을 정밀하게 반영한 버킷기초의 강성 산정방법이 필요하다. 본 연구에서는 다양한 사질토의 마찰각과 버킷기초 형상에 대한 유한요소해석을 수행하여 기초의 강성을 산정하였으며, 해석결과로부터 정규화된 기초강성 매트릭스가 제안되었다. 제안된 버킷기초의 강성 산정방법은 설계에 직접 적용될 수 있는 유용한 결과라고 판단된다.

Keywords

References

  1. Achmus, M., Akdag, C. T. and Thieken, K. (2013), Load-bearing behavior of suction bucket foundations in sand, Applied Ocean Research, Vol. 43, pp. 157-165. https://doi.org/10.1016/j.apor.2013.09.001
  2. Achmus, M., Kuo, Y. S. and Abdel-Rahman, K. (2009), Behavior of monopile foundations under cyclic lateral load, Computers and Geotechnics, Vol. 36, No. 5, pp.7 25-735. https://doi.org/10.1016/j.compgeo.2008.12.003
  3. Brinkgreve, R. B. J. and Vermeer, P. A. (1999), Plaxis: finite element code for soil and rock analyses: version 7, Balkema, pp. 1-376.
  4. Choi, C., Han, J., Cho, S. and Jang, Y. (2013), The effect of flexibility for the offshore wind turbine system, Journal of the Korean Geoenvironmental Society, Vol. 14, No. 4, pp. 59-66.
  5. Darendeli, M. B. (2001), Development of a new family of normalized modulus reduction and material damping curves, The University of Texas at Austin, pp. 1-362.
  6. Doherty, J. and Deeks, A. (2003), Elastic response of circular footings embedded in a non-homogeneous half-space, Geotechnique, Vol. 53, No. 8, pp. 703-714. https://doi.org/10.1680/geot.2003.53.8.703
  7. Gazetas, G., Anastasopoulos, I., Adamidis, O. and Kontoroupi, T. (2013), Nonlinear rocking stiffness of foundations, Soil Dynamics and Earthquake Engineering, Vol. 47, pp. 83-91. https://doi.org/10.1016/j.soildyn.2012.12.011
  8. Houlsby, G. T., Ibsen, L. B. and Byrne, B. W. (2005), Suction caissons for wind turbines, Frontiers in Offshore Geotechnics: ISFOG, Perth, WA, Australia, pp. 75-93.
  9. Itasca (2011), FLAC, Fast Lagrangian analysis of continua, Minneapolis, pp. 1-3058.
  10. Jung, S., Kim, S.-R. and Patil, A. (2015), Effect of monopile foundation modeling on the structural response of a 5-MW offshore wind turbine tower, Ocean Engineering, Vol. 109, pp. 479-488. https://doi.org/10.1016/j.oceaneng.2015.09.033
  11. Kim, D. J., Youn, J. U., Jee, S. H., Choi, J., Lee, J. S. and Kim, D. S. (2014), Numerical studies on bearing capacity factor $N{\gamma}$ and shape factor of strip and circular footings in sand according to dilatancy angle, Journal of the Korean geotechnical Society, Vol. 30, No. 1, pp. 49-63 (in Korean). https://doi.org/10.7843/kgs.2014.30.1.49
  12. Kwak, D. Y., Brandenberg, S. J., Mikami, A. and Stewart, J. P. (2015), Prediction equations for estimating shear-wave velocity from combined geotechnical and geomorphic indexes based on Japanese data set, Bulletin of the Seismological Society of America, Vol. 105, No. 4, pp. 1919-1930. https://doi.org/10.1785/0120140326
  13. Loukidis, D. and Salgado, R. (2009), Bearing capacity of strip and circular footings in sand using finite elements, Computers and Geotechnics, Vol. 36, No. 5, pp. 871-879. https://doi.org/10.1016/j.compgeo.2009.01.012
  14. Park, J. S., Park, D. and Yoo, J. K. (2016), Vertical bearing capacity of bucket foundations in sand, Ocean Engineering, Vol. 121, No. 1, pp. 453-461. https://doi.org/10.1016/j.oceaneng.2016.05.056
  15. Park, J. S., Park, D., Yoon, S. W. and Jang, H. S. (2015), Vertical load transfer mechanism of bucket foundation in sand, Journal of the Korean geotechnical Society, Vol. 31, No. 7, pp. 1-11.
  16. Veritas, D. N. (2004), Design of offshore wind turbine structures, Offshore Standard DNV-OS-J101, Vol. 6, pp. 2004.
  17. Wolff, T. F. (1989), Pile capacity prediction using parameter functions, Predicted and Observed Axial Behavior of Piles: Results of a Pile Prediction Symposium: ASCE, pp. 96-106.