Journal of Korea Water Resources Association (한국수자원학회논문집)

Korea Water Resources Association (한국수자원학회)
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Comparative analysis of caisson sections of composite breakwaters evaluated by Level I reliability-based design method

Level I 신뢰성 기반 설계법에 의해 산정된 혼성제 케이슨 단면의 비교 분석

  • Lee, Cheol-Eung (Department of Architectural, Civil, and Environmental Engineering, Kangwon National University) ;
  • Park, Dong Heon (Department of Architectural, Civil, and Environmental Engineering, Kangwon National University) ;
  • Kim, Sang Ug (Department of Architectural, Civil, and Environmental Engineering, Kangwon National University)
  • 이철응 (강원대학교 공과대학 건축토목환경공학부) ;
  • 박동헌 (강원대학교 공과대학 건축토목환경공학부) ;
  • 김상욱 (강원대학교 공과대학 건축토목환경공학부)
  • Received : 2018.03.12
  • Accepted : 2018.03.27
  • Published : 2018.07.31
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Abstract

A methodology has been presented for evaluating the partial safety factors on the sliding failure mode of vertical caissons of composite breakwaters and for determining the cross sections of those by Level I reliability-based design method. Especially, a mathematical model has been suggested for the sake of a consistency of code format as well as convenience of application in practical design, for which the uncertainties associated with buoyancy and its own weight can be taken into account straightforwardly. Furthermore, design criteria equation has been derived by considering accurately the effect of uplift pressure, so that the cross sections of caissons can be assessed which must be safe against the sliding failure. It has been found that cross sections estimated from partial safety factors proposed in this paper are in very good agreement with the results of Level II AFDA and Level III MCS under the same target probability of failure. However, partial safety factors of the Technical Standards and Commentaries for Port and Harbour Facilities in Japan and Coastal Engineering Manual in USA tend to estimate much bigger or smaller cross sections in comparison to the present results. Finally, many reliability re-analyses have been performed in order to conform whether the stability level of cross section estimated by Level I reliability-based design method is satisfied with the target probability of failure of partial safety factors or not.

혼성제 직립 케이슨의 활동에 대한 부분안전계수 산정과 Level I 신뢰성 기반 설계법에 의한 단면 결정 과정을 자세히 제시하였다. 특히 본 연구에서는 형식의 일치성과 실무에서의 적용 편이성을 위하여 부력 및 자중과 직접적으로 관련된 수위 및 케이슨을 구성하는 재료의 불확실성을 고려할 수 있는 수학적 모형을 제시하였다. 또한 양압력에 대한 영향을 정확히 고려하여 활동에 대해 안정한 혼성제 직립 케이슨 단면을 산정할 수 있는 설계기준식을 유도하였다. 본 연구에서 제시한 부분안전계수를 가지고 Level I 신뢰성 기반 설계법에 의해 산정된 단면이 동일한 목표파괴확률에 대한 Level II AFDA의 결과 및 Level III MCS의 결과와 매우 잘 일치하였다. 그러나 미국 및 일본의 항만 설계기준에서 제시한 부분안전계수를 이용한 결과는 그 보다 훨씬 크거나 작은 단면을 산정하고 있다. 마지막으로 부분안전계수의 목표수준과 Level I 신뢰성 기반 설계법으로 결정된 단면의 안정성 수준에 대한 일치성 여부를 확인하기 위한 다각적인 신뢰성 재해석이 수행되었다.

Keywords

References

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