• Journal of the Korean Institute of Navigation
• /
• v.13 no.1
• /
• pp.77-106
• /
• 1989

Two numerical models of the shoreline change and sediment transport rates, explicit and implicit, are simulated with shore structures such as breakwaters, a jetty, groins and a seawall. The applied study area is songdo Beach, Youngil bay, Korea since it has all the shore structures mentinoed above. The two models investigate the beach line changes and sedimen transport rates for the beach before design of three groins with and without an offshore breakwater. In order to estimate the shoreline changes after three groins were built, the beach response inside the three groin compartiments and the offshore barrier are also investigated. The simulation based on the initial shoreline conditions surveyed by the Hydrographic office, Koreai 1979 and 1984. The breaking wave characteristics are introduced into the models by calculation from the empirical equations and modification from the numerical and hydraulic model test results developed for waves behind an offshore breakwater. The numerical simulation describes well the tendencies of the sand transport and shoreline changes affected by wave diffraction behind a detached breakwater and by interruption of sand transport at three groins.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2007.05a
• /
• pp.2117-2119
• /
• 2007

최근의 이상기후에 따른 악영향으로 항만구조물의 설계시 중요한 요소인 심해설계파가 증고되었다. 최근, 증고된 설계파에 대해 마루높이의 절감 및 단면축소에 따른 경제적 효과를 극대화시키기 위하여, 사석경사제형 제체 상부에 이중곡면 반파공을 적용한 각종 구조물형식이 도입되고 있는 추세이다. 본 연구에서는 수리모형실험을 통해 월파와 안정성 검토를 수행하여 방파제의 최적 단면을 선정하였다. 본연구의 수리모형실험에 적용된 단면형식은 총 4가지로 각각에 대해 월파량과 반사율을 측정하여 비교 검토하였다. 그 결과 TTP로 피복된 제체 상부에 이중곡면 반파공을 설치한 단면이 가장 우수한 단면으로 선정되었다. 또한, 이중곡면 반파호안의 계획과 설계시 체계적인 검토와 합리적인 단면계획을 수립하여 이를 통해 마루높이 절감에 따른 경제적 효과의 극대화를 기대할 수 있다.

• Journal of Navigation and Port Research
• /
• v.33 no.2
• /
• pp.105-110
• /
• 2009

Shipwaves am have harmful effects on ships working on the sea, in a harbour or navigational channel and caused beach erosion, seawall destruction. This study aims to investigate describe the characteristics of the wave pattern generated by an individual model ship tested at different velocities and hull forms for a given water depth and to investigate the variations at a given distance from the sailing line under the same conditions. As a result, the angles a's by model ship tests are smaller than those by real ship ones. Wave heights decreases with an increasing the mid-ship cross sectional area $A_s$. The maximum wave height and period increase rapidly in the subcritical speed, and beyond the critical speed the height and period decrease with increasing depth Froude number. And the period keeps constant with the distance from the sailing line.

• Journal of Industrial Technology
• /
• v.9
• /
• pp.3-19
• /
• 1989

Shoreline have been changed from time immemorial continuously, three-quarters of the population of the world live by the sea. It is not too much to say that all of us who live in Han penisular live by coastal zone because we can reach in the beach within only for hours. In this way effectual use and menagement of coastal zone is very importent problems in side of protection of marine resources as well as land use. But it has problems which change of shoreline have to be surveyed and to be predictived. This study the pattern and characteristics of the East sea coast including investigations of the shoreline changes of the East sea. This report gives a description of the method for implementing the seawall boundary condition in the shoreline change numerical model. Such analytical solutions can provide a simple and economical means to make a quick qualitative evaluation of shoreline response under a wide range of environmental and engineering conditions.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2018.05a
• /
• pp.206-208
• /
• 2018

울산신항의 활발한 개발로 인하여 기존에 설치되어 있던 온산항북방파제는 원래의 목적인 방파제로서의 기능은 사라지고, 울산항 3항로에 간섭된 지장물이 됨에 따라, 기존방파제의 철거를 수행하였으며 철거순서는 상치 콘크리트 깨기, 속채움 제거, 케이슨 절단 및 천공, 인양 및 제거, 케이슨 파쇄의 순서로 진행되었다. 특히, 파쇄한 콘크리트는 크라싱 작업을 통해 재생골재로 생산하였으며, 향후 신설케이슨의 속채움 재료로 재활용하는 것으로 하여 경제적 자원재활용에도 기여하고 있다.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.35 no.4
• /
• pp.75-83
• /
• 2023

Apart from implementing hardware solutions like raising the crest freeboard of coastal structures to efficiently counter wave-overtopping, there is a simultaneous requirement for software-driven disaster mitigation strategies. These tactics involve the swift and accurate dissemination of wave-overtopping information to the inland regions of coastal zones, enabling the regulation of evacuation procedures and movement. In this study, a method was proposed to estimate wave-overtopping by utilizing the temporal variation of wave heights exceeding the structure's crown level, with the aim of developing an on-site wave measurement system for providing wave-overtopping information in the field. Laboratory model experiments were conducted on vertical seawall structures to measure wave-overtopping volumes and wave runup heights under different wave conditions and structural freeboard variations. By assuming that the velocity of water inundation on the top of the structure during wave-overtopping events is equivalent to the long-wave velocity, an overtopping discharge coefficient was introduced. This coefficient was utilized to estimate the rate of wave-overtopping based on the temporal changes in wave runup heights measured at the top of the structure. Upon reasonably calculating the overtopping discharge coefficient, it was verified that the estimation of wave-overtopping could be achieved solely based on the wave runup heights.

• Asian Journal of Atmospheric Environment
• /
• v.10 no.2
• /
• pp.114-123
• /
• 2016

A change in chemical compositions of Asian dust (AD) particles can dramatically alter their optical properties, cloud-forming properties, and health effects. The present study was undertaken to evaluate this aging of AD particles by means of two complementary methods (i.e., the traditional spot test and the most advanced micro-PIXE analytical technique) for single particle analysis. Size-classified particles were sampled at the rural peninsula of Korea (Byunsan, 35.37N; 126.27E) during AD event and non-AD period in 2004. Sulfate was principally enriched on the particles in the size range of $7.65-10.85{\mu}m$ collected during AD event. The average number fraction of coarse particles ($>2.05{\mu}m$) containing chloride was 16.2% during AD event. Relatively low particles containing nitrate compared to those containing sulfate and chloride were found in AD event. Micro-PIXE elemental maps indicated that a large number of AD particles were internally mixed with man-made zinc. The highest peaks of EC and OC concentrations were appeared at $0.01-0.43{\mu}m$ particle aerodynamic diameter. High EC concentration in $PM_1$ was might be caused by the Saemangeum Seawall Project that was being conducted during our field measurement.

• Structural Engineering and Mechanics
• /
• v.53 no.3
• /
• pp.393-410
• /
• 2015

Two dimensional numerical models and physical models have been developed to study the highly nonlinear interactions between waves and breakwaters, but several of these models consider the effects of the structural dynamic responses and the shape of the breakwater axis on the wave pressures. In this study, a multi-material Arbitrary Lagrangian Eulerian (ALE) method is developed to simulate the nonlinear interactions between nonlinear waves and elastic seawalls on a coastal rubble mound breakwater, and is validated experimentally. In the experiment, a solitary wave is generated and used with a physical breakwater model. The wave impact is validated computationally using a breakwater - flume coupling model that replicates the physical model. The computational results, including those for the wave pressure and the water-on-deck, are in good agreement with the experimental results. A local breakwater model is used to discuss the effects of the structural dynamic response and different design parameters of the breakwater on wave loads, together with pressure distribution up the seawall. A large-scale breakwater model is used to numerically study the large-scale wave impact problem and the horizontal distribution of the wave pressures on the seawalls.

• Journal of Korean Society of Steel Construction
• /
• v.11 no.3 s.40
• /
• pp.259-270
• /
• 1999

In this study, establishment of standard design procedure and optimum dimension of the embedded steel-plate cellular bulkheads for seawall structures in deep water sites has been presented. A computer program was developed to asses feasible dimensions of steel-plate cell, and general equations to determine optimum cell diameter and embedment depth are derived for sand. A model experiment to verify the necessary driving force of vibratory hammer system was also performed and driving force data pertinent to optimum cell dimension are presented.

• Journal of Navigation and Port Research
• /
• v.31 no.5 s.121
• /
• pp.339-344
• /
• 2007

Shipwaves can cause beach erosion, seawall destruction and difficulty of cargo working due to rolling of ship. In addition, high speed operation of motor boat and passenger ship jeopardize sea bathers and anglers' safety. This study aims to investigate the characteristics of shipwaves which occurred and propagated in shallow water experimentally and theoretically. Shipwaves which occurred and propagated in shallow water depth represent large wave height increase.