Journal of the Korean Society of Marine Environment & Safety (해양환경안전학회지)

The Korean Society of Marine Environment and safety (해양환경안전학회)
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Analysis of Extreme Wave Conditions for Long-Term Wave Observation Data Considering Directionality

방향성을 고려한 장기 파랑관측자료의 극치파랑조건 분석

  • Kim, Gunwoo (Department of Ocean Civil Engineering, Mokpo National Maritime University)
  • 김건우 (목포해양대학교 해양건설공학과)
  • Received : 2022.06.02
  • Accepted : 2022.08.29
  • Published : 2022.08.31
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Abstract

In this study, deepwater design waves were estimated for 16 wave directions and various return periods based on statistical analysis of extreme waves observed for more than 20 years at three stations (Chilbal-do, Geomun-do, Donghae). These values were compared with design waves estimated based on the omni-directional wave data. The Weibull distribution was used as the probability distribution function whose parameters were determined by the least square method. The Kolmogorov-Smirnov test was applied for the goodness of fit test. Notably, the directional design waves were smaller than the omni-directional design wave for every wave direction. The maximum 50-year wave heights for directional sectors were 7.46 m (NNE), 12.05 m (S), and 9,59 m (SSW) at Chilbal-do, Geomun-do and Donghae whereas those for uni-directional wave data were 7.91 m, 13.82 m and 10.38 m, respectively. This implied possible under-estimation of the deepwater design waves for 16 wave directions being currently used in the design of offshore and coastal structures.

본 연구에서는 칠발도, 거문도, 동해에서 20년 이상 관측된 파랑자료를 16 방위별 극치확률분석을 통해 재현빈도별 심해설계파를 산정하였고, 이 값을 방향을 고려하지 않은 전방향파의 심해설계파와 비교하였다. Weibull 분포함수를 확률분포함수로 사용하였으며, 최소자승법을 사용해서 매개변수를 결정하였다. 추정된 분포함수는 Kolmogorov-Smirnov 방법을 사용하여 적합도를 검증하였다. 그 결과 방향별로 구한 심해설계파가 전방향파의 심해설계파보다 모든 방향에서 상대적으로 작은 것으로 나타났다. 파향별로 구한 50년 빈도 설계파고는 칠발도, 거문도, 동해에서 각각 7.46 m(NNE), 12.05 m(S), 9.69 m(SSW)가 최대값이지만, 전방향파로 구한 설계파고는 각각 7.91 m, 13.82 m, 10.38 m이었다. 이는 현재 해양 및 연안 구조물 설계에 사용하고 있는 16 방위별 심해설계파고가 과소산정되었을 가능성이 있음을 보여준다.

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