• 한국항해항만학회지
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• 제38권6호
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• pp.673-681
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• 2014

Due to the increased demand for safety and security requirements on the port infrastructure, the harbor tranquility is one of the important parameter in the mooring basin of harbor. It relates keenly to berthing/unberthing and cargo handling works but also it is an important indicator to get the minimum water area as the safe refuge. Hupo harbor is a national coastal harbor located in east coast of Korea and a development plan for a new marina near the entrance is being carried out including berth layouts, breakwater extensions, 300m marina berths, dredging and land reclamation works. The new plan will impact on calmness of the existing port. Therefore, it is necessary to analyze in complex the variation of wave height and direction caused by wave refraction, diffraction, shoaling and reflection from the incident waves from outside the harbor. In order to check the calmness inside a harbor, the numerical models are being used currently need fundamental reviews according to the difference of results which depend on their respective features. In this study, hence, it was introduced the validity of numerical models by comparing the computational results with the hydraulic model experiment. The current investigations contribute to the existing development recommendations and provide further solutions for port planning.

• Structural Engineering and Mechanics
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• 제43권5호
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• pp.679-690
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• 2012

A new concept sea-floating port called mobile harbor has been introduced, in order to resolve the limitation of current above-ground port facilities against the continuous growth of worldwide marine transportation. One of important subjects in the design of a mobile harbor is to secure the dynamic stability against wave-induced excitation, because a relatively large-scale heavy crane system installed at the top of mobile harbor should load/unload containers at sea under the sea state up to level 3. In this context, this paper addresses a two-step sequential analytical-numerical method for analyzing the structural dynamic response of the mobile harbor crane system to the wave-induced rolling excitation. The rigid ship motion of mobile harbor by wave is analytically solved, and the flexible dynamic response of the crane system by the rigid ship motion is analyzed by the finite element method. The hydrodynamic effect between sea water and mobile harbor is reflected by means of the added moment of inertia.

• 한국항만학회지
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• 제15권1호
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• pp.57-74
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• 2001

In the past, the predictions of beach processes and harbor sedimentation were mainly relied on the hydraulic model tests and empirical methods. In recent years, however, as computers have come into wide use, more accurate models have gradually been developed and thus replaced those conventional methods. For prediction of topographical change near the coastal area, we need informations of wave and current conditions in the numerical model which should be calculated in advance. Numerical model introduced in this study combines wave refraction-diffraction, breaking, bottom friction, lateral mixing, and critical shear stress and three sub-models for simulating waves, currents, and bottom change were briefly discussed. Simulations of beach processes and harbor sedimentation were also described at the coast neighboring Bangpo Harbor, Anmyundo, Chungnam, where the area has suffered accumulation of drifting sand in a small fishing harbor with a wide tidal range. We also made model test for the new layout of the harbor and planned south breakwater for preventing intrusion of sand. Although the model study gave reasonable description of beach processes and harbor sedimentation mechanism, it is necessary to collect lots of field observation data, including waves, tides and bottom materials, etc. for better prediction.

• 한국통신학회논문지
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• 제36권3B호
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• pp.268-274
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• 2011

최근에 들어서 얕은 바다에서 대형 선박의 하역을 손쉽게 처리하기 위한 모바일 하버의 도입에 대한 논의와 연구가 활발히 진행되고 있다. 이에 본 연구에서는 대형 선박이 정박할 수 없는 얕은 바다에서도 화물을 싣고 내릴 수 있는 이동형 부두 시스템인 모바일 하버에 대하여 선박의 도착에서 하적에 이르기까지의 서비스를 자동으로 관리하는 모바일 하버 서비스 관리 시스템을 개발하였다. 이를 위해 먼저 최근에 등장한 새로운 개념인 모바일 하버의 동작 원리를 정의하고 모바일 하버와 대형 선박의 행동 특성함수를 정의하였다. 이어서 모바일 하버와 서비스 관리 시스템이 정보를 주고받는 과정을 정의하고 그에 따른 기능을 시뮬레이터로 구현하였다. 마지막으로 개발한 시뮬레이터를 이용한 모의실험을 통하여 제안한 방법의 유효성을 제시하였다.

• 한국해양공학회지
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• 제22권1호
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• pp.46-52
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• 2008

Lately Gun-Jang Harbor has undergone a drastic change in hydraulic characteristics due to newly added harbor protection measures, like a wharf and breakwater. The wharf and breakwater, with a training dike, were constructed to keep enough depth far navigation. They make the plan view of Gun-Jang Harbor semi closed and very elongated, which makes it very vulnerable to seiche. Hence it is an urgent task to unveil the hydraulic characteristics, like seiche, for the optimal operation of the new harbor system. In this study, we numerically analyze the seiche characteristics of Gun-Jang Harbor over the $10-4{\sim}10-3$ Hz frequency range, considering that wind waves due to seasonal winds are the most prevailing during winter in the West sea. As a wave driver, we use Mild Slope Eqs. and numerically integrate these using FEM based on Galerkin weak formulation. It turns out that the 1st, 2nd, 3rd and 4th eigen models are over 0.0009 Hz, 0.0013 Hz, 0.0017 Hz and 0.002 Hz.

• 한국해안해양공학회지
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• 제16권3호
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• pp.178-189
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• 2004

본 논문에서는 장기간 측정된 파랑자료를 이용하여 신뢰성 있는 항만설계를 하기 위한 평상파 산정에 대한 방법론을 제시하였다. 제안된 방법론을 부산항 내 해경부두 설계에 적용하여, 부산항 입구 조도 전면해상에서 장기간 측정된 파랑자료를 이용하여 97.5% 평상파를 산정하였다. 1993년 2월부터 2002년 12월까지 측정된 파랑자료를 파향별로 유의파고와 유의파주기의 결합분포를 구한 후, 포물선형 완경사 방정식 파랑모델을 이용하여 해경부두에서의 평상파 조건을 산정하였다. 해경부두 위치에서의 항만설계를 위한 97.5% 평상파의 파고는 1.06 m 이며, 이는 부산항 항외에서 입사되는 파향 E, 유의파고 1.75 m, 유의파주기 7 sec에 의해 생성되는 것으로 분석되었다. 부산항 내 풍파에 의한 평상파에의 영향을 검토하였으나, 항내 풍파는 평상파 산정에 영향이 없으며 항외에서 항내로 진입하는 너울성 파고의 영향이 지배적임이 밝혀졌다. 따라서 항내의 풍파의 영향만을 고려하여 평상파를 추정하였을 경우 심각한 오류가 있음을 알 수 있었다.

• 대한토목학회논문집
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• 제26권6B호
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• pp.651-660
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• 2006

외해에 접해 있는 항만은 항내정온도가 항만설계기준에 만족 되도록 설계되었을 지라도 계류선박의 동요 때문에 하역에 지장을 초래하고 가동률이 저하되는 현상이 빈번하게 발생하고 있다. 이것은 항만설계기준이 항내 파고만으로 설정되었기 때문이며, 이와 같은 현상을 방지하기 위해서는 계류선박의 동요를 고려한 새로운 가동률 평가방법이 필요하다. 본 연구는 선박동요해석모형을 이용하여 항내에 계류된 선박의 동요량을 산정하고 하역허용동요량과의 관계로부터 하역허용파고를 산정한 후 항만의 가동률을 평가하는 방법을 제시한 것이다. 여기서는 새로운 가동률 평가 방법을 현지 항만인 온산항에 적용하고 현행 평가 방법과 비교하여 두 방법의 차이를 제시하였다. 새로운 방법에 의한 항만가동률은 ENE와 NE방향에서 현행 항만설계기준에 의한 가동률 결과 보다 1~11% 정도 낮아 지는 것을 확인할 수 있었다. 따라서 외해에 접해 있는 항만은 설계 단계에서 파고 기준에 의한 항만가동률 평가뿐만 아니라 계류선박의 동요를 고려한 가동률 평가를 병행하여 평면배치 계획을 수립하여야 할 것이다.

• Selected Papers of The Society of Naval Architects of Korea
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• 제2권1호
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• pp.47-62
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• 1994

Herein the surge-heave-pitch motion of a ship in harbor has been analyzed within the framework of linear potential theory. The ship is assumed to be slender and moored at an arbitrary position in a rectangular harbor with a constant depth. The coast line is assumed to be straight. The ship and harbor responses to incident long waves are represented in terms of Green's function, which is the solution of tole Helmholtz equation satisfying necessary boundary conditions. An integral equation is obtained from matching condition between harbor and ocean solutions, and it is replaced by an equivalent variational form. Numerical results sallow that the ship motion can be highly amplified at the frequencies, where the harbor is resonated by the incident wave. At the resonant frequencies, the added mass for vertical motions becomes negative and the damping forte changes abruptly.

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 2003년도 한국해안해양공학발표논문집
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• pp.179-184
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• 2003

It is inevitable for dredging to increase the suspended sediment concentration (SSC) of the ambient waters in some degree, which has the potential to affect the coastal ecosystem in various manners. Thus, quantitative under- standing of dredging-induced sediment loss is essential fur the reliable environmental impacts assessment. (omitted)

• 산업기술연구
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• 제14권
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• pp.101-107
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• 1994

This study is to investigate harbor oscillation phenomenon according to combination of the wall structures by model experiment in a three dimensional wave basin. Six different types of wall combination were chosen through combination of erect wall, erect dissipation block, and sand beach, wave height at selected points in the harbor were measured by electronic wave gage. Test results show that the wall structure composed solely of erect walls showed generally highest harbor oscillation. Since natural beach shows lower reflection than erect dissipation block do, we thought it would be more efficient to use natural beach for improved harbor oscillation. The result showed, however, that the erect dissipation block are more efficient than natural beach to attain less harbor oscillation. The reason seens that the erect dissipation blocks have better capability to control breaking wave on the surface of the structure.