Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Effect of Lateral Load-Moment Combination on p-y Curves of Large Diameter Monopile for Offshore Wind Turbine: Centrifuge Model Tests

해상풍력 대구경 모노파일의 p-y 곡선에 대한 수평-모멘트 조합의 영향: 원심모형실험

  • Lee, Min Jy (Dept. of Civil Environmental Engrg., Kongju National Univ.) ;
  • Yun, Jong Seok (Dept. of Civil Environmental Engrg., Kongju National Univ.) ;
  • Choo, Yun Wook (Dept. of Civil Environmental Engrg., Kongju National Univ.)
  • 이민지 (공주대학교 건설환경공학과) ;
  • 윤종석 (공주대학교 건설환경공학과) ;
  • 추연욱 (공주대학교 건설환경공학과)
  • Received : 2019.12.16
  • Accepted : 2020.02.17
  • Published : 2020.02.29
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Abstract

In this study, centrifuge tests were performed to investigate the effect of the lateral load-moment combination on the p-y curves for 7 m-diameter monopiles installed in sand for offshore wind turbine. For the objectives, a centrifuge testing system was developed and tests were conducted at an acceleration of 68.83 g using well-instrumented model monopiles under two different lateral load-moment combinations simulated by different loading heights: 1 and 5 times monopile diameter from the ground surface. The sand was prepared as medium loose sand. Based on the centrifuge test results, the experimental p-y curves were evaluated and compared with previous literatures including API codes. The experimental results reveal that the p-y curves were little influenced by the combination of lateral load and moment. It was also found that the embedded length affects p-y curves.

본 연구에서는 모래지반에 설치된 해상풍력 지지용 직경 7m 모노파일의 p-y 곡선에 대한 수평하중-모멘트 조합의 영향을 분석하기 위하여 원심모형실험을 수행하였다. 이를 위하여 원심모형실험시스템을 구축하였고, 다수의 게이지를 부착한 계측용 모노파일 모형을 사용하여 68.83g에서 원심모형실험을 수행하였다. 지표면으로부터 직경의 1배와 직경의 5배 높이에서 하중재하를 하는 2개의 수평하중-모멘트 조합으로 재하시험이 수행되었다. 모형지반은 중간밀도의 모래로 조성되었다. 원심모형실험결과로부터 실험 p-y 곡선을 산정하였고 기존 문헌의 p-y 곡선과 비교하였다. 결과적으로 p-y 곡선에 대한 모멘트 조합의 영향이 미미함을 확인하였다. 또한, 근입깊이가 모노파일의 p-y 곡선에 영향을 미치는 것을 확인하였다

Keywords

References

  1. Achmus, M., Rahman, K. A., and Peralta, P. (2005), "On the Design of Monopile Foundations with Respect to Static and Quasi-static Cyclic Loading", Copenhagen offshore wind 2005.
  2. Achmus, M., Kuo, Y. S., and Rahman, K.A. (2009), "Behavior of Monopile Foundations under Cyclic Lateral Load", Computers and Geotechnics 36, pp.725-735. https://doi.org/10.1016/j.compgeo.2008.12.003
  3. Alderlieste, E. A., Dijkstra, J., and Van Tol, A. F. (2011), "Experimental Investigation into Pile Diameter Effects of Laterally Loaded Mono-piles", Proceedings of the ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering OMAE 2011, Rotterdam, The Netherlands.
  4. API (American Petroleum Institute). (2011), "Geotechnical and Foundation Design Considerations", Washington, DC.
  5. Bayton, S. and Black, J. (2016), "The Effect of Soil Density on Offshore Wind Turbine Monopile Foundation Performance", Proc. In the 3rd Eurofuge, Vol.16 pp.245-251.
  6. Bienen, B. and Klinkvort, R. T., Fan, S., Black, J., Bayton, S., Thorel, L., Blanc, M., Madabhushi, G. S. P., Haigh, S., Broad, T., Zania, V., Askarinejad, A., Li, Q., Kim, D. S., Park, S., Almeida, M., Barra, M. F. W., Prendergast, L., Kong, D., and Zhu, B. (2019), "Centrifuge Benchmark Testing of Laterally Loaded Monopiles in Sand", Procds. of the 16th Asian Regional Conference on soil mechanics and Geotechnical Engineering.
  7. Choo, Y. W., Kim, D. W., Park, J. H., Kwak, K. S., Kim, J. H., and Kim, D. S. (2014), "Lateral Response of Large Diameter Monopiles for Offshore Wind Turbines from Centrifuge Model Tests", Geotechnical Testing Journal, Vol.37, No.1.
  8. Choo, Y. W. and Kim, D. W. (2016), "Experimental Development of the p-y Relationship for Large-diameter Offshore Monopiles in Sands: Centrifuge Tests", J. Geotech. Geoenviron. Eng., 2016, Vol. 142, No.1, 04015058. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001373
  9. DNV (Det Norske Veritas). (2014), "Design of Offshore Wind Turbine Structures" DNV-OS-J101, Hlvik, Norway.
  10. Doherty, P. and Gavin, P. (2012), "Laterally Loaded Monopile Design for Offshore Wind Farms", Article in Energy, Vol.165, No.1, pp.7-17.
  11. Dyson, G. J. and Randolph, M. F. (2001), "Monotonic Lateral Loading of Piles in Calcareous Sand", J. Geotech. Geoenviron. Eng. 2001. Vol.127, pp.346-352. https://doi.org/10.1061/(ASCE)1090-0241(2001)127:4(346)
  12. Haiderali, A. E. and Madabhushi, G. S. P. (2013), "Evaluation of the p-y Method in the Design of Monopiles for Offshore Wind Turbines", Offshore Technology Conference OTC 24088, Texas, USA.
  13. Hearn, E. N. and Edgers, L. (2010), "Finite Element Analysis of an Offshore Wind Turbine Monopile", GeoFlorida 2010: Advances in Analysis, Modeling & Design, GSP 199 (C) 2010 ASCE.
  14. Kim, K. J., Nam, B. H., and Youn, H. J. (2015), "Effect of Cyclic Loading on the Lateral Behavior of Offshore Monopiles Using the Strain Wedge Model", Hindawi Publishing Corporation Mathematical Problems in Engineering. Vol.2015, pp.12.
  15. Kirkwood, P. (2015) "Cyclic Lateral Loading of Monopile Foundations in Sand", Ph. D. Thesis, University of Cambridge.
  16. Klinkvort, R. T. (2018), "Monopile Design through Centrifuge Technology", OSIG Evening Geoforum, OSIG-SUT London, UK.
  17. Klinkvort, R. T., Leth, C. T., and Hededal, O. (2010), "Centrifuge Modelling of a Laterally Cyclic Loaded Pile", Physical Modelling in Geotechnics - Springman, Laue & Seward (eds) (C) 2010 Taylor & Francis Group, London, ISBN 978-0-415-59288-8.
  18. Kong, L. G. and Zhang, L. M. (2006) "Rate-controlled Lateral-load Pile Tests Using a Robotic Manipulator in Centrifuge", Geotech. Test.J., Vol.30(3), pp.192-201.
  19. Lee, M. J., Yoo, M. T., Bae, G. T., Kim, Y. S., Nam, B. H., and Youn, H. J. (2019), "Centrifuge Tests on the Lateral Behavior of Offshore Monopile in Saturated Dense Sand under Cyclic Loading", Journal of Testing and Evaluation, Vol.47, No.3, pp.1809-1828.
  20. Moller, I. F. and Christiansen, T. H. (2011), "Laterally Loaded Monopile in Dry and Saturated Sand-static and Cyclic Loading; Experimental and Numerical Studies", Master Project, June 2011 Aalborg University Esbjerg.
  21. O'Neill, M. W. and Murchison, J. M. (1983), "An Evaluation of p-y Relationships in Sands", Research Rep. Dept. of Civil Engineering, Univ. of Houston, Houston, No. GT-DF02-83.
  22. Park, J. O., Choo, Y. W., and Kim, D. S. (2009), "Evaluating of Bearing Capacity of Piled Raft Foundation on OC Clay Using Centrifuge and Numerical Modeling", Journal of the Korean Geotechnical Society, KGS, Vol.25, pp.23-33
  23. Rahman, K. A. and Achmus, M. (2005), "Finite Element Modelling of Horizontally Loaded Monopile Foundations for Offshore Wind Energy Converters in Germany", Institute of Soil Mechanics, Foundation Engineering and Waterpower Engineering, University of Hannover, Germany.
  24. Wilson, D. (1998), "Soil-pile-superstructure Interaction in Liquefying Sand and Soft clay", Ph. D. dissertation, University of California, Davis, CA
  25. Yang, K. and Liang, R. (2006) "Methods for Deriving p-y Curves from Instrumented Lateral Load Tests", Geotech. Test. J., Vol.30(1), pp.1-8.