• Title/Summary/Keyword: Breakwater development

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

  • Kang, Yeoun-Ike;Shim, Min-Bo;Shim, Sung-Hyun;Kim, Ha-Young;Shim, Jae-Bum;Chun, Youn-Chul;Yoon, Jung-Ik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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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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Stability Evaluation of Rear-Parapet Caisson Breakwaters under Regular Waves by Numerical Simulation (수치해석을 통한 규칙파를 받는 후부 패러핏 케이슨 방파제의 안정성 평가)

  • Lee, Byeong Wook;Park, Woo-Sun;Ahn, Sukjin
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.2
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    • pp.95-105
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    • 2020

  • In this study, using the CADMAS-SURF model, the characteristics of the wave pressures and the wave forces were analyzed according to the installation position of the parapet on top of the caisson, and the stability evaluation was carried out using estimated wave forces for the design wave condition. Numerical results show that adopting the rear-parapet reduces the front maximum wave pressures and wave forces, and the maximum wave pressure acting on the rear-parapet increases slightly compared to the front parapet, but the wave force acting on the rear-parapet has little effect on the stability of the breakwater due to the phase difference with the wave force acting on the front of the breakwater. In addition, impulsive wave pressures did not occur, as Yamamoto et al. (2013) pointed out the problem of the rear-parapet breakwater. As a result of the stability against sliding and overturning, it was estimated that the target safety factor of 1.2 could be secured by the self-weight of 13% less than the case of the front parapet. At this time, the maximum ground pressure was also reduced by 30%, and the applicability of the rear-parapet structure to the actual site was evaluated as high.

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

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

  • SOHN BYUNG-KYU;KIM HONG-JIN;AN HEUI-CHUN
    • Journal of Ocean Engineering and Technology
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    • v.19 no.2 s.63
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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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