KSCE Journal of Civil and Environmental Engineering Research (대한토목학회논문집)

Korean Society of Civil Engeneers (대한토목학회)
권호 표지
DOI QR코드

DOI QR Code

Experimental Study on Wave-Induced Hydraulic Pressure subjected to Bottom of Floating Structures

부유구조체 하면에 작용하는 파압에 대한 실험적 연구

  • 정연주 (한국건설기술연구원 SOC 성능연구소) ;
  • 유영준 (한국건설기술연구원 SOC 성능연구소) ;
  • 이두호 (한국건설기술연구원 SOC 성능연구소)
  • Received : 2011.08.02
  • Accepted : 2011.10.11
  • Published : 2011.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, in order to investigate the wave-induced buoyancy effects, experimental studies were conducted on pontoon-type floating structures. A series of small-scale tests with various wave cases were performed on the pontoon models. A total of four small-scale pontoon models with different lateral shapes and bottom details were fabricated and tested under the five different wave cases. Six hydraulic pressure gauges were attached to the bottom surfaces of the pontoon models and the wave-induced hydraulic pressure was measured during the tests. Finally, hydraulic pressures subjected to the bottoms of the pontoon models were compared with each other. As the results of this study, it was found that whereas the waffled bottom shape hardly influenced the wave-induced hydraulic pressure, the hybrid lateral shape significantly influenced the wave-induced hydraulic pressure subjected on the bottoms of floating structures. The air gap effects of the hybrid shape contribute to decreasing the wave-induced hydraulic pressure due to absorption of wave impact energy. Compared with box type, the hydraulic pressures of the hybrid type were about 83% at the bow, 74% at the middle, and 53% at the stern.

본 연구에서는 파랑하중에 의해 부유구조체 하면에서 발생하는 파압 현상을 규명하기 위한 실험적 연구를 수행하였다. 서로 다른 측면 형상과 하면 형상을 갖는 4개의 폰툰형 시험체를 제작하여 5 종류 파랑하중에 대한 수리모형실험을 실시하였다. 시험체의 하면에는 6개의 파압센서를 설치하였으며, 수리모형실험 동안 시험체 하면에 작용하는 파압을 측정하였다. 측정된 파압을 분석한 결과, 와플형의 하면 형상은 부유구조체 하면에 작용하는 파압에 거의 영향을 미치지 않으며, 하이브리드형의 측면 형상은 파압에 상당한 영향을 미치는 것으로 나타났다. 이것은 하이브리드형의 측면에 형성된 에어갭(Airgap)이 부유구조체에 작용하는 파랑의 충격 에너지를 일부 흡수하여 파압을 저감시키는데 기여하는 것으로 판단된다. 기존의 상자형 폰툰과 비교하였을 때 하이브리드형의 파압은 선수부에서 약 83%, 중간부에서 약 74% 및 선미부에서 약 53% 수준인 것으로 나타났다.

Keywords

References

  1. 위엔후탄, 노혁천, 김승억, 나성원(2009) 파랑하중에 대한 초대형 콘크리트 부유식 구조물의 설계 부재력 산정. 대한토목학회논문집, 대한토목학회, 제29권 제6A호, pp. 641-650.
  2. 지광습, 김진균, 이승오, 이필승(2010) 초대형 부유식 해상 구조 물의 초기 설계를 위한 설계차트 개발. 대한토목학회 논문집, 대한토목학회, 제30권 제3B호, pp. 315-324.
  3. 해양수산부(2005) 항만 및 어항 설계기준.
  4. Allen, E., Dees, D., Hicks, S., Hollibaugh, R., Martin, T., and Starling, T. (2006) Design of a Floating Production Storage and Offloading Vessel for Offshore Indonesia-Final Report, Texas A&M University, Texas.
  5. Haveman, C., Parliament, J., Sokol, J., Swenson, J., and Wangner, T. (2006) Design of a Floating Production Storage and Offloading Vessel for Operation in the South China Sea-Final Report, Texas A&M University, Texas.
  6. Huang, W. and Moan, T. (2005) Combination of global still-water and wave load effects for reliability-based design of floating production, storage and offloading(FPSO) vessels. Applied Ocean Research, Vol. 27, pp. 127-141. https://doi.org/10.1016/j.apor.2005.11.006
  7. Jeong, Y.J., Cho, J.Y., You, Y.J., and Na, S.W. (2010) Stability and wave-induced bending moment for design of offshore floating terminal. 9th Pacific Structural Steel Conference 2010, Beijing, pp. 369-374.
  8. Jung, D.H., Kim, H.J., Kim, J.H., and Moon, D.S. (2006) A preliminary experimental study for development of floater of floating breakwater, J. of the Korean Society for Marine Environmental Engineering, Vol. 9, No. 3, pp. 141-147.
  9. Koutandos, E.V., Karambas, T.V., and Koutitas, C.G. (2004) Floating breakwater response to waves action using a boussinesq model coupled with a 2D velliptic solver. J. of Waterway, Port, Coastal, and Ocean Engineering ASCE, Vol. 130, No. 5, pp .243-255. https://doi.org/10.1061/(ASCE)0733-950X(2004)130:5(243)
  10. Lanquetin, B., Collet, P., and Esteve, J. (2007) Structural integrity management for a large prestressed concrete floating production unit. 26th International Conference on Offshore Mechanics and Arctic Engineering, SanDiego, CA, pp. 1-12.
  11. Link, R.A. and Elwi, A.E. (1995) Composite concrete-steel plate walls: analysis and behavior. Journal of Structural Engineering ASCE, Vol. 121, pp. 260-271. https://doi.org/10.1061/(ASCE)0733-9445(1995)121:2(260)
  12. OTRC (2010) Design of Floating Production Systems. University of Texas at Austin, Texas.
  13. Palo, P. (2005) Mobile offshore base: hydrodynamic advancements and remaining challenges. Marin Structures, Vol. 18, pp. 133- 147. https://doi.org/10.1016/j.marstruc.2005.07.007
  14. Pham, D.C. and Wang, C.M. (2010) Optimal layout of gill cells for very large floating structures. J. of Structural Engineering- ASCE, Vol. 136, No. 7, pp. 907-916. https://doi.org/10.1061/(ASCE)ST.1943-541X.0000182
  15. Zijian, Y. (2007) Very Large Floating Container Terminal and Optimal Layout of Gill Cells, MSc Thesis, National University of Singapore, Singapore.