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

Korean Society of Coastal and Ocean Engineers (한국해안·해양공학회)
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A Study on Minimization of Harbor Oscillations by Infragravity Waves Using Permeable Breakwater

투과제를 이용한 중력외파의 항내 수면진동 저감 방법에 대한 연구

  • Kwak, Moon Su (Department of Civil Engineering, Myongji College) ;
  • Jeong, Weon Mu (Maritime ICT R&D Center, Korea Institute of Ocean Science Technology)
  • 곽문수 (명지전문대학교 토목공학과) ;
  • 정원무 (한국해양과학기술원 해양ICT융합연구센터)
  • Received : 2020.11.18
  • Accepted : 2020.12.07
  • Published : 2020.12.31
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Abstract

In this study, the minimization of harbor oscillation using permeable breakwater was applied to the actual harbor and investigated an effect of minimization by computer simulation in order to take into account the water quality problems and measures of harbor oscillation by infragravity waves at the same time. The study site is Mukho harbor located at East coast of Korea that harbor oscillation has been occurred frequently. The infragravity waves obtained by analyzing the observed field data for five years focused on the distribution between wave periods of 40 s and 70 s and wave heights in less than 0.1 m was 94% of analyzing data. The target wave periods was 68.0 s. The most effective method of minimization of harbor oscillation by infragravity waves was to install a detached permeable breakwater with transmission coefficient of 0.3 on the outside harbor and replace some area of the vertical wall in the harbor with wave energy dissipating structure to achieve a reflectivity of 0.9 or less. The amplitude reduction rate of this method shown in 27.4%. And the effect of the difference in transmission coefficient of permeable breakwater on the reduction rate of the amplitude was not significant.

본 연구는 장주기 파의 항내 수면진동 대책과 수질 문제를 동시에 고려하기 위하여 투과방파제를 활용하는 수면진동 저감 방법을 실제 해역에 적용하고 Boussinesq 파랑모델을 이용하여 저감 효과를 수치적으로 검토한 것이다. 본 연구에서는 중력외파에 의한 항내 수면진동 문제가 빈번히 발생하는 동해안의 묵호항을 연구대상으로 하였으며, 5년간의 장기 파랑관측 자료를 분석하여 파악한 묵호 수역의 중력외파는 주기는 40 s~70 s 사이에 집중 분포하였고 파고는 0.1 m 이하가 분석대상 자료의 94%이었다. 저감 목표 주기는 항내 수면진동 해석을 실시하여 첨두 주기 68.0 s로 결정하였으며, 가장 효과적인 수면진동 저감 방법은 항 외측에 투과율 0.3의 투과방파제를 도제로 설치하고 항내 안벽의 일부 구역을 파랑에너지흡수 구조형식으로 교체하여 중력외파에 의한 반사율을 0.9 이하로 하는 방법이었다. 이 방법의 진폭 감소율은 27.4%이었다. 그리고 투과방파제의 투과율 차이가 중력외파에 의한 항내 수면진동의 진폭 감소율에 미치는 영향은 크지 않았다.

Keywords

Acknowledgement

본 논문은 정부(교육부)의 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업임(No.2017R1D1A1B03032990).

References

  1. Bertin, X., Bakker, A., Dongeren, A., Coco, D., Andre, G., Ardhuin, F., Bonneton, P., Bouchette, F., Castelle, B., Crawford, W., Davidson, M., Deen, M., Dodet, G., Guerin T., Inch, K., Leckler, F., McCall, R., Muller, H., Olabarriet a, M., Roelvink, D., Ruessink, G., Sous, D., Stutzmann, E. and Tissier, M. (2018). Infragravity waves: From driving mechanisms to impacts. Earth-Science Review, 177, 774-799. https://doi.org/10.1016/j.earscirev.2018.01.002
  2. Biesel, F. (1952). equations genrales au second ordre de la houle irrguliere. La Houille Blanche, 7, 372-376. https://doi.org/10.1051/lhb/1952033
  3. Cho, H.Y., Jeong, W.M. and Oh, S.H. (2014). Analysis on the characteristics of the infra-gravity waves inside and outside pohang new harbor using a transfer function model. Journal of KSCOE, 26(3), 131-139 (Korean).
  4. Coastal Engineering Committee, JSCE (1993). Research report on investigation and design method of waves, structures and foundations, 58p. (Japanese).
  5. Diaz-Hernandez, G., Lara, J.L. and Losada, I.J. (2016). Extended long wave hindcast inside port solutions to minimize resonance. Journal of Marine Science and Engineering, 4(1), 9. https://doi.org/10.3390/jmse4010009
  6. Gonzalez-Escriva, J.A. and Medina, J.R. (2012). ANTIREFLECTIVE VERTICAL STRUCTURE EXTENDED FOR ATTENUATION OF LOW FREQUENCY WAVES, Proceedings of 33th ICCE, ASCE, 1-9.
  7. Gonzalez-Escriva, J.A., Molines, J, Medina, J.R. and GomezMartin, M.E. (2018). ANALYSIS OF LONG-CIRCUIT TYPE CAISSONS FOR ATTENUATION OF LONG-PERIOD WAVES, Proceedings of 36th ICCE, ASCE, 1-8.
  8. Hiraishi, T., Hirayama, K., Kozawa, K. and Moriya, Y. (2009). Wave Absorbing Capacity of Long Period Wave Countermeasures in Harbor, Technical note of the port and airport research institute, No.1205.
  9. Jeong, W.M., Chae, J.W., Jun, K.C., Lee, J.C., Cho, H.Y., Kim, Y.K., Baek, W.D., Park, S.J. and Kim, M.K. (1997). A Study on the Propagation of Bound Waves, Report of KORDI, No. BSPE 97625-00-1055-2 (Korean).
  10. Jeong, W.M., Chae, J.W., Park, W.S., Lee, K.S. and Suh, K.D. (2001a). Correlation betwenn stom waves and far-infra-gravity waves observed in okkye harbor. Journal of KSCOE, 13(3), 209-229 (Korean).
  11. Jeong, W.M., Park, W.S., Suh, K.D., Lee, K.S. and Kim, J.H. (2001b). Reducing harbor resonance by dredging of harbor basin. Journal of KSCOE, 13(2), 122-138.
  12. Jeong, W.M., Park, W.S., Chae, J.W. and Suh, K.D. (2002). A countermeasure to harbor resonances induced by far-infra-gravity waves in mukho harbor. Journal of KSCE, 22(2-B), 213-226 (Korean).
  13. Jeong, W.M., Choi, H.J., Cho, H.Y. and Oh., S.H. (2016). Comparison of the shallow-water design wave height on the Korean East coast based on wave observation data and numerical simulation. Journal of KSCOE, 28(5), 292-302 (Korean).
  14. Jeong, W.M., Back, J.D., Choi, H.J. and Kim, S.I. (2018). Analysis on the reduction effects of the gravity waves and infra-gravity waves of detached submerged breakwater by field monitoring. Journal of KSCOE, 30(2), 51-60 (Korean).
  15. Kwak, M.S., Jeong, W.M., Pyun, C.K., Xing, X. and Lee, J.J. (2008). COMPUTER SIMULATION of POHANG NEW HARBOR FOR SEICHE REDUCTION, Proceedings of 31th ICCE, ASCE, 3996-4001.
  16. Lee, K.H., Beom, S.S., Kim, D.S., Choi, N.H., Park, J.B. and An, S.W. (2012). Application of wave resonator to the field for controlling secondary undulation. Journal of KSCOE, 24(1), 58-65 (Korean).
  17. Longuet-Higgins, M. and Stewart, R. (1962). Radiation stress and mass transport in gravity waves, with application to surf beats. J. Fluid Mech., 13, 481-504. https://doi.org/10.1017/S0022112062000877
  18. Madsen, P.A., Sorensen, O.R. and Schaffer, H.A. (1997). Surf zone dynamics simulated by a Boussinesq type model. Part I: Model description and cross-shore motion of regular waves. Coastal Eng., 32, 255-288. https://doi.org/10.1016/S0378-3839(97)00028-8
  19. MIKE BY DHI (2009a). MIKE 21 Boussinesq Wave Module User Guide. 7-121.
  20. MIKE BY DHI (2009b). MIKE 21 Boussinesq Wave Module Scientific Documentation. 12-14.
  21. Munk, W. (1949). Surf beat. Eos Trans. AGU, 30, 849-854. https://doi.org/10.1029/TR030i006p00849
  22. Nakamura, T., Mochizuki, H. and Morita, S. (1996). PERFORMANCE OF A RESONATOR DESIGNED BY THE WAVE FILTER THEORY-APPLICABILITY TO A HARBOR, Proceedings of 25th ICCE, ASCE, 1280-1292.
  23. Okihiro, M., Guza, R.T. and Seymour, R.J. (1993). Excitation of seiche observed in a small harbor. J. Geophys. Res., 98, 18.201-18.211. https://doi.org/10.1029/93JC01760
  24. Poon, Y.K., Raichlen, F. and Walker, J.K. (1998) Application of Physical Model in Long Wave Studies for The Port of Long Beach, Proceedings of 26th International Conference on Coastal Engineering, ASCE, 1222-1235.
  25. Shiraishi, S, Kubo, M., Ueda, S. and Sakakibara, S. (1995). Measures of ship motion induced by long waves using mooring system. Proceedings of Conference on Coastal Engineering, JSCE, 42, 941-945 (Japanese).
  26. Sorensen, O.R., Schaffer, H.A. and Sorensen, L.S., (2004). Boussinesq-type modelling using an unstructured finite element technique. Coastal Eng., 50, 181-198. https://doi.org/10.1016/j.coastaleng.2003.10.005
  27. Suganuma, H., Kamiyama, S., Atsumi, Y. and Koizumi, N. (1995). Prediction of frequency of long waves and ship motion occurrence. Proceedings of Conference on Coastal Engineering, JSCE, 42, 951-955 (Japanese).
  28. Symonds, G., Huntley, D., and Bowen, A.J. (1982). Two-dimensional surf beat: long wave generation by a time-varying breakpoint. J. Geophys. Res., 87, 492-498. https://doi.org/10.1029/JC087iC01p00492
  29. Tai, L.H., Xing, X. and Lee, J.J. (2008). Improving Harbor Resonance Induced by Typhoon Waves for Hualien Harbor, Proceedings of 31th ICCE, ASCE, 1236-1248.
  30. Thotagamuwage, D.T.P. (2014) Harbour oscillations: Generation and minimization of their impacts, Thesis for the degree of Doctor of Philosophy, School of Civil Environmental and Mining Engineering, University of Western Australia.
  31. van der Molen, W., Scott D., Taylor, D. and Elliott, T. (2016). Improvement of mooring configurations in geraldton harbour. Journal of Marine Science and Engineering, 4(1), 3. https://doi.org/10.3390/jmse4010003