• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.199-202
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• 2018

현재 대규모 항만국가공사 대부분은 대수심, 고파랑 지역에 위치하고 있어 대안설계 진행시는 해당 해역의 특성을 고려한 설계파 산정, 평면 및 단면계획, 구조물의 안정성 검토 등의 사항을 기존설계 대비 상향시켜 설계에 반영하고 있는 사례를 최근 발주된 동해항 3단계 방파호안 축조공사를 사례를 들어 최근 설계방향성을 검토함.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.71-75
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• 2003

최근 특별한 연약지반 처리공법을 적용하지 않고 자중을 감소시키고 구조적인 특성을 이용하여 연약지반 위에 설치하는 방파제가 제안ㆍ개발되고 있다. 일본에서는 자중을 가볍게 하고 파랑 하중을 역T형 구조와 말뚝을 이용하여 지지하는 구조를 시공한 사례도 있으며(문사강지 등, 1989), 국내에서는 Fig. 1과 같이 역T형 콘크리트 방파제의 자중만으로도 과도한 압밀침하가 발생되는 아주 연약한 지반에서 방파제의 자중을 줄이기 위해 부력통을 설치하고 설계 하중은 지중에 벽체를 설치하여 지지하는 구조를 제안하고 그 성능을 평가한 바 있다(권오순 등,2001 ; 권오순 등, 2002). (중략)

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.1-7
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• 2005

In order to secure the traffic safety especially in the entrance waterway of harbour, it is important that the breakwater and the port facilities should be designed properly considering ship-handling difficulty and traffic flow. In this study, the lateral force acting on ship hull under the external force(wind, current, wave) is investigated quantitatively for the container ship approaching to the Busan and Gamcheon breakwater. The relation of ship-handling difficulty to the breakwater and the arrangement of ship's routine are examined based on the lateral force under the external force. Some of reviews to secure traffic safety on the design of breakwater are discussed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.1
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• pp.11-16
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• 2020

The rotational stability of an interlocking caisson breakwater was studied. Using the analytical solution for the linear wave incident to the infinite breakwater, the phase difference effect of wave pressures in the direction of the breakwater baseline is considered, and Goda's wave pressure formula in the design code is adopted to consider the nonlinearity of the design wave. The rotational safety factor of the breakwater was defined as the ratio of the rotational frictional resistance moment due to caisson's own weight and the acting rotational moment due to the horizontal and vertical wave forces. An analytical solution for the rotational center point location and the minimum safety factor is presented. Stability assessment formula were proposed to be applicable to all design wave conditions used in current port and harbor structure design such as regular waves, irregular waves and multi-directional irregular waves.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.36 no.2
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• pp.50-60
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• 2024

To promote the application of reliability-based design within the Korean coastal engineering community, the author conducted reliability analyses and optimized the design of a vertical-type breakwater, considering multiple limit states in the seas off of Pusan and Gunsan - two representative ports in Korea. In this process, rather than relying on design waves of a specific return period, the author intentionally avoided such constraints. Instead, the author characterized the uncertainties associated with wave force, lift force, and overturning moment - key factors significantly influencing the integrity of a vertical-type breakwater. This characterization was achieved by employing a probabilistic model derived from the frequency analysis results of long-term in-situ wave data. The limit state of the vertical-type breakwater encompassed sliding, overturning, and collapse failure, with the close interrelation between wave force, lift force, and moment described using the Nataf joint probability distribution. Simulation results indicate, as expected, that considering only sliding failure underestimates the failure probability. Furthermore, it was shown that the failure probability of vertical-type breakwaters cannot be consistently secured using design waves with a specific return period. In contrast, breakwaters optimally designed to meet the reliability index requirement of 𝛽-3.5 to 4 consistently achieve a consistent failure probability across all sea areas.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.287-292
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• 2021

Load and resistance factor design is an efficient design approach that provides a system of consistent design solutions. This study aims to determine the load and resistance factors needed for the design of breakwater foundations within a probabilistic framework. In the study, four typical types of Korean breakwaters, namely, rubble mound breakwaters, vertical composite caisson breakwaters, perforated caisson breakwaters, and horizontal composite breakwaters, are investigated. The bearing capacity of breakwater foundations under wave loading conditions is thoroughly examined. Two levels of the target reliability index (RI) of 2.5 and 3.0 are selected to implement the load and resistance factors calibration using Monte Carlo simulations with 100,000 cycles. The normalized resistance factors are found to be lower for the higher target RI as expected. Their ranges are from 0.668 to 0.687 for the target RI of 2.5 and from 0.576 to 0.634 for the target RI of 3.0.

• Journal of the Korean Geotechnical Society
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• v.21 no.1
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• pp.29-41
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• 2005

The small harbors and fishing ports in Korea have less economic efficiency if the previous construction method of breakwater would be utilized due to bad ground conditions in spite of low design waves. Therefore, it is necessary to develop a new type breakwater economically applicable to the cases with low design wave. In this study, a soldier pile type breakwater, which is found to be economic and can be easily constructed on the ground without any need of treatment of the ground, was newly introduced. The effects of embedded depth, reinforcement methods as well as pile types including saw type and flat type on the lateral behavior of the proposed breakwaters installed in loose sandy soils were investigated from model test. The test results revealed that the lateral resistance increases by increasing the embedded depth and by adopting the reinforcement techniques such as raker and anchor. Furthermore, it was also verified that the saw type breakwater shows better geotechnical performance than the flat type breakwater.

• 어항어장
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• s.44
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• pp.67-75
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• 1998

본 연구의 목적은 서로 다른 형태를 갖는 피복블록의 형상에 따른 Hudson식의 안정계수 값들과 양압력의 관계를 방파제의 안정성과 연계 해석하여, 방파제 단면설계에 있어서 피복블록의 선택 및 소요중량 산정에 효과적으로 이용하고자 한다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.1
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• pp.21-32
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• 2003

In this study, the reliability design method developed by Hanzawa et al. in 1996 for calculation of the expected damage to armor blocks of a horizontally composite breakwater is extended to take into account the variability in wave direction such as directional spreading of waves, obliquity of the design principal wave direction from the shore-normal direction, and its variation about the design value. To calculate the transformation of random directional waves. the model developed by Kweon et al. in 1997 is used instead of Goda's model, which was developed in 1975 for unidirectional random waves normally incident to a straight coast with parallel depth contours and has been used by Hanzawa et al. It was found that the variability in wave direction had great influence on the computed expected damage to armor blocks. The previous design, which disregarded wave directionality, could either overestimate or underestimate the expected damage by a factor of two depending on water depth and seabed slope, if the assumption of the present study that the stability formula for breakwater armor blocks proposed for normal incidence can be used for obliquely incident waves is valid.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.3
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• pp.123-133
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• 2018

We studied the change process in the design parameters (conditions) of structural sections of vertical/slope breakwaters in Korea over the long term based on an analytical review of the latest design recommendations. This study found the following. 1) Design wave heights have increased gradually with the increase in the wave height of deep sea waves. 2) The relative design wave height ($H_{1/3}/h$) changed from 0.5 in the 1970s to 0.6~0.7 today. This means that design wave heights are overestimated compared with the water depth. 3) Before 1999, the design water level was based on high water during an average spring tide, but this has been increased since 2000 because of additional consideration of anomalous sea levels. 4) Before 1999, the relative crest heights of the investigated breakwaters was 0.6~0.7, but after 1999 this increased to a mean of 1.0 and maximum of 1.26.