Journal of Korean Society of Coastal and Ocean Engineers (한국해안·해양공학회논문집)

Korean Society of Coastal and Ocean Engineers (한국해안·해양공학회)
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Dispersion Characteristics of Wave Forces on Interlocking Caisson Breakwaters by Cross Cables

크로스 케이블로 결속된 인터로킹 케이슨 방파제의 파력분산특성

  • Seo, Ji Hye (Coastal Engineering Division, Korea Institute of Ocean Science & Technology) ;
  • Yi, Jin Hak (Coastal Engineering Division, Korea Institute of Ocean Science & Technology) ;
  • Park, Woo Sun (Coastal Engineering Division, Korea Institute of Ocean Science & Technology) ;
  • Won, Deck Hee (Coastal Engineering Division, Korea Institute of Ocean Science & Technology)
  • 서지혜 (한국해양과학기술원 연안공학연구본부) ;
  • 이진학 (한국해양과학기술원 연안공학연구본부) ;
  • 박우선 (한국해양과학기술원 연안공학연구본부) ;
  • 원덕희 (한국해양과학기술원 연안공학연구본부)
  • Received : 2015.07.16
  • Accepted : 2015.09.21
  • Published : 2015.10.31
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Abstract

Damage level of coastal structures has been scaled up according to increase of wave height and duration of the storm due to the abnormal global climate change. So, the design criteria for new breakwaters is being intensified and structural strengthening is also conducted for the existing breakwaters. Recently, interlocking concept has been much attention to enhance the structural stability of the conventional caisson structure designed individually to resist waves. The interlocking caisson breakwater may be survival even if unusual high wave occurs because the maximum wave force may be reduced by phase lags among the wave forces acting on each caisson. In this study, the dispersion characteristics of wave forces using interlocking system that connect the upper part of caisson with cable in the normal direction of breakwater was investigated. A simplified linear model was developed for computational efficiency, in which the foundation and connection cables were modelled as linear springs, and caisson structures were assumed to be rigid. From numerical experiments, it can be found that the higher wave forces are transmitted through the cable as the angle of incident wave is larger, and the larger the stiffness of the interlocking cable makes larger wave dispersion effect.

이상 기후현상으로 인해 폭풍의 강도가 커지고, 지속시간 또한 길어지고 있어 연안 피해가 점차 대규모화 되고 있다. 이러한 변화에 대응하기 위하여 기존 방파제에 대한 평가기준과 신설 방파제의 설계기준이 강화되고 있다. 최근 케이슨식 방파제의 구조적 안정성을 향상시키기 위하여 개별 케이슨이 독립적으로 파에 저항하도록 하였던 방파제 케이슨을 서로 인터로킹시키는 방안이 관심을 받고 있다. 이는 각각의 케이슨에 작용하는 힘을 분산시켜 이상파랑이 발생할 경우에도 최대파력이 저감되어 방파제의 안정성을 확보할 수 있도록 한 것이다. 본 연구에서는 케이블을 이용하여 케이슨 상부를 방파제 기준선방향으로 인터로킹시켰을 때의 파력의 분산특성에 대해서 분석하였다. 수치계산의 효율을 위해 지반과 연결 케이블은 선형 스프링으로 모형화하고 케이슨은 강체로 가정한 정적 선형모델을 개발하였다. 수치해석 결과, 입사각이 커질수록 케이블을 통하여 전달되는 파력비가 높아지고, 인터로킹 케이블의 강성이 클수록 전달 파력비가 증대되어 파력분산 효과가 높아지는 특성을 확인할 수 있었다.

Keywords

References

  1. Battjes, J.A. (1982). Effect of short-crestedness on wave loads on long structures, Applied Ocean Research, 4(3), 165-172, 1982. https://doi.org/10.1016/S0141-1187(82)80053-9
  2. Chae, J.W. et al. (2013). Extreme Waves Generated by Typhoon Bolaven (201215) in Southern Korean Waters, Proc. 7th Int. Conf. on Asian and Pacific Coasts, 996-1001.
  3. Dalrymple, R. A., and Dean, R. G. (1991). Water wave mechanics for engineers and scientists. Prentice-Hall,
  4. Emanuel, K.A. (2013). Downscaling CMIP5 climate models shows increased tropical cyclone activity over the 21st century, Proceedings of the National Academy of Sciences, 110(30), 12219-12224. https://doi.org/10.1073/pnas.1301293110
  5. Gleixner, S., Keenlyside, N., Hodges, K. I., Tseng, W. L., and Bengtsson, L. (2014). An inter-hemispheric comparison of the tropical storm response to global warming, Climate Dynamics, 42(7-8), 2147-2157. https://doi.org/10.1007/s00382-013-1914-6
  6. Goda, Yoshimi. (2010). Random Seas and Design of Maritime Structures. World Scientific, 708.
  7. Hyndai Dvp. company. (2009). Report of Alternative-design of Counter Facilities Construction at Yeongil Bay Port in Pohang (Stage 2-1)
  8. Hyndai Dvp. company. (2011). Report of Basic Design of South-Breakwater at Yeongil Bay Port in Pohang (Stage 1 on Zone 1)
  9. Kim, B.H., Lee, J.W., Park, W.S. and Jung, J.S. (2010). Making Long Caisson Breakwater Using interlocking System, KSCE J. Civil Engrg., 58(12), 65-71.
  10. Kim, B.H., Kim, J.S., Park, S.Y. and Kim, J.W. (2011). Design Case of the 3D Interlocking Breakwater, Proc. KAOSTS '11 Conf., 1903-1906.
  11. Korea Hydrographic and Oceanographic Administration (KHOA). (2012). Data report of typhoon Bolaven (201215). l2a.
  12. National Typhoon Center. (2011). Typhoon White Book, 11-1360016-000001-01.
  13. Newmark, Nathan M. and Rosenblueth, Emilio. (1971). Fundamentals of Earthquake Engineering, Prentice Hall, Inc.
  14. Park, S.H., Park, W.S. and Kim, H.S. (2011). Evaluation of Structural Behavior for Interlocking Breakwater, Proc. KAOSTS '11 Conf., pp. 1915-1918.
  15. Park, W.S., Yi, J.H., Won, D.H., and Seo, J.H. (2013). Dispersion Characteristics of Wave Forces on Interlocking Caisson Breakwaters, Proc. KSCDP '13 Conf., 70.
  16. Takahashi, S., and Shimosako, K. (1990). Reduction of wave force on a long caisson of vertical breakwater and its stability. Technical Notes No. 685, Port and Harbour Research Institute, Yokosuka, Japan.
  17. Takayama, T. and Higashira, K. (2002). Statistical analysis on damage characteristics of breakwaters. Proc. of Ocean Development Conf., 18, 263-268. (in Japanese).

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