• 제목/요약/키워드: Breakwater development

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방파제 기초에 적용된 고품질 DCM공법의 설계 및 시공 사례 (A Case Study on the High-quality DCM applied to the Foundation of Breakwater)

  • 강연익;심민보;심성현;김하영;심재범;천윤철;윤종익
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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    • pp.815-826
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    • 2009

  • The paper presents a case study addressing the design and construction aspects for DCM(Deep Cement Mixing) method employed as the foundation of a caisson type breakwater with heavy weight(10,700 ton/EA) and a high design wave height($H_{1/3}$=8.7m). The DCM was designed for the project(Ulsan New Port North Breakwater Phase 1) by optimizing the pattern of DCM columns with a combination of short and long columns (i.e., block type(upper 3m)+wall type(lower)) and considering overlapped section between columns as a critical section against shear force where the coefficient of effective width of treated column($\alpha$) was estimated with caution. It was shown that the value can be 0.9 under the condition with the overlapped width of 30cm. In addition to that, a field trial test was performed after improving conventional DCM equipment (e.g., mixing blades, cement paste supplying pipes, multi auger motor, etc.) to establish a standardized DCM construction cycle (withdrawal rate of mixing blades) which can provide the prescribed strength. The result of the field strength test for cored DCM specimens shows that the averaged strength is larger than the target strength and the distribution of the strength(with a defect rate of 7%) also satisfies with the quality control normal distribution curve which allows defect rate of 15.9%.

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수치해석을 통한 규칙파를 받는 후부 패러핏 케이슨 방파제의 안정성 평가 (Stability Evaluation of Rear-Parapet Caisson Breakwaters under Regular Waves by Numerical Simulation)

  • 이병욱;박우선;안석진
    • 한국해안·해양공학회논문집
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    • 제32권2호
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    • pp.95-105
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    • 2020

  • 본 연구에서는 CADMAS-SURF 모형을 사용하여 케이슨 직립제의 상부에 패러핏의 설치 위치에 따라서 규칙파에 의한 파압과 파력의 특성을 분석하였고, 파력결과를 사용하여 방파제 및 지반 안정성 평가를 수행하였다. 수치해석결과, 후부 패러핏을 채택하면 전면 최대 파압 및 파력을 저감시킬 수 있으며, 패러핏에 작용하는 최대 파압은 전면에 있는 경우에 비하여 다소 증가하나 전면 최대 파압과의 위상차에 의해 방파제의 안정성에는 거의 영향을 미치지 못함을 확인하였다. 그리고 Yamamoto et al.(2013)이 후부 패러핏의 문제점으로 지적한 바 있는 충격파압은 발생하지 않았다. 활동, 전도에 대한 안정성 검토 결과, 후부 패러핏 구조를 채택하면 항외측에 패러핏을 설치한 경우에 비하여 13% 적은 자중으로도 목표 안전율인 1.2를 확보할 수 있는 것으로 평가되었다. 이때 최대 지반지지력도 30% 감소되는 것으로 확인되어 후부 패러핏 구조의 실제 현장에서의 적용성이 높은 것으로 평가되었다.

  • https://doi.org/10.9765/KSCOE.2020.32.2.95 인용 PDF KSCI

경사식 방파제의 형상에 따른 월파량 및 반사율 실험 연구 (Experimental Study of the Wave Overtopping/Reflection Rate on the Shapes of Rubble Mound Structures)

  • 손병규;김홍진;안희춘
    • 한국해양공학회지
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    • 제19권2호
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    • pp.34-39
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    • 2005

  • All of the design criterion are not only formulated by an internal study, concerning the design of maritime structures, but also by the guarantee that internal design technology is essential, at least according to theoretical and experimental studies. Furthermore, the basic data, which is necessary for the development of a more stable design of breakwater structures, should be ensured, according to current research and analysis of damage created by water waves. According to the necessity to solve the problems that occur in the design and construction of ocean structures, until now, it is recognized that the hydraulic experiments are important. This paper provides the design of structures to decrease the energy created by waves. Suggestions to make contributions to the development of ocean/fisheries technology are also discussed. It is better to use S-type coastal structures/breakwaters than to use uniform type breakwaters, concerning stability, reflection, and overtopping.

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