• Proceedings of the Korean Society of Disaster Information Conference
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• 2016.11a
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• pp.181-182
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• 2016

방조제 차수공사를 실시하는 현장 지반의 하부에 철재이물질과 돌망태 와이어 등이 매립되어 있는 것으로 확인된 상황에서 강널말뚝(sheet pile)을 풍화대까지 항타하는 것이 현실적으로 불가능하므로 상부는 철재이물질(돌망태 등)이 없는 심도까지 T-4 및 Vibro Hammer 에 의한 강널말뚝(sheet pile)을 이용하여 차수하고, 철재이물질과 돌망태 와이어 등이 매립되어 있는 것으로 확인된 하부 풍화대까지는 그라우팅에 의한 차수를 시도하는 현장차수방법을 시공하여 성공적으로 차수결과를 얻을 수 있었다.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.118-123
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• 2003

재래식 방파제는 투수성이 작아 항내ㆍ외간 해수유통을 저하시켜 조석간만의 차가 작은 해역의 항만에서는 오염원이 유입될 때 수질이 쉽게 악화된다. 특히 방파제 후면 수역을 매립하여 선착장으로 이용하는 경우에 이 현상은 심화된다 이를 해결하려면 육상으로부터의 오염원 유입을 저감시킴과 함께 정체된 항에 흐름이 존재하도록 하는 건설 공법을 도입할 필요가 있다. (중략)

• Journal of the Korean Professional Engineers Association
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• v.39 no.3 s.186
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• pp.27-31
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• 2006

The Saemangeum project, which began in 1991, is designed to convert about 120 million pyeong of mud flats into farmland and a reservoir by building a 33-kilometer seawall off the coast. Many scientists and specialists will continue to monitor and study the effects of the damming up and how it will affect the ocean environment. The long-term plans and visions for development of Saemangeum are needed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.4
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• pp.348-359
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• 2006

The city of Mokpo suffers lowland inundation damages by sea water flooding even without harsh weather like a typhoon, due to the low level urban infrastructure facilities, oceanic environmental changes by constructions of seadike/seawall and sea level rise caused by global warming. This study performs constructing the simulation system which employs the MIKE21 software. And the system is applied to several typhoon- induced surges which had resulted in inundation at Mokpo. Virtual situation of flooding is simulated in case 59 cm of surge height, which had been occurred actually by RUSA(0215), coincides with Approx. H.H.W. Then the water level of 545 cm corresponds to the extreme high water level(544 cm) for 10 year return period after the construction of Geumho seawall. The results show rapid and broad inundation at Inner-Port, requiring additional preparations for flood protections.

• Journal of Korean Society of Steel Construction
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• v.9 no.2 s.31
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• pp.249-257
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• 1997

This study will present the experimental research on the establishment of design considerations and structural integrity of the placed steel-plate cell methods for seawall and waterbreak, which have some benefits in the aspects of construction cost, time and equipments compared with the existing methods. The behavior of steel-plate cell structure is complicate due to stiffeners and cell-arc junction. There is also an ambiguity on lateral pressure by cell and arc filler. To resolve such problems, full scale cell $(D11.0^m{\times}H14.0^m{\times}12t)$ has been designed and fabricated, then placed on the seabed and filled. The strain measurement has also been performed to build up the design technology together with numerical analysis.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.331-335
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• 2004

This study is focused to analyze the movement of thermal effluent dischargeed from nuclear power plant by season, ebb and flow, and before and after foundation of tide embankment using thermal infrared band image of 28 scenes observed from Landsat from 1987 to 2004, which is the early stage of operation of young-kwang nuclear power plant. In diffusion of thermal effluent discharge by seasons, spring and summer is spreading further than autumn and winter. It is considered to distribute widely mixed with thermal effluent discharge and hot water, which is distributed naturally along the seaside. It is known the fact that tidal currents control the direction of diffusion of thermal effluent discharge by the change of ebb and flow. Namely, it is distributed widely on the Southwest direction along the seaside by tidal currents when ebb and, it is moved widely on the Northeast direction along the seaside by tidal current when flood. However, in the early stage of flood current, the mainstream of thermal effluent discharge is spread on Southwest direction and, the direction is changed on North­east way when the latter period of flood current. Similarly, in the early stage of ebb current, the mainstream of thermal effluent discharge is spread on Northeast direction and, the direction is changed on Southwest direction when the latter period of ebb current. As the result of comparing to the diffusion pattern of thermal effluent discharge before and after the foundation of seawall, discharged thermal effluent from the drain of plant by the foundation of dike is shown as curved circle pattern on Northeast to West direction from the ending portion of the seawall.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.4
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• pp.242-251
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• 2020

In this study, the extraction efficiency and reflection coefficient by a two-dimensional OWC (Oscillating Water Column) WEC (wave energy converter) installed in front of a seawall was investigated for regular/irregular waves. The matched eigenfunction expansion method (MEEM) based on the linear potential theory was applied as an analytical tool. The diffraction problem by the incident wave in the open-chamber and the radiation problem by the oscillating pressure in the closed-chamber were solved to obtain the volume fluxes at the internal free-surface. Applying the volume fluxes into the continuity equation for the airflow in a chamber, we got the oscillating air pressure. The maximum extracted power and corresponding reflection coefficient were determined at the optimal turbine coefficient that maximizes the extracted power. OWC device designed for a high extracted efficiency simultaneously contributes to reduce reflected waves.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.4
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• pp.119-127
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• 2022

To investigate varying wave impact pressure exerting at the crest wall of rubble mound seawall, depending on breaking wave properties, regular waves with different wave periods were generated. Wave velocity fields and void fraction were measured using bubble image velocimetry and simple combined wave gauge system (Na and Son, 2021). For the waves with shorter wave period, maximum horizontal velocity was less reduced compared to incident wave speed while breaking-induced air entrainment was occurred intensely, leading to a significant reduction of wave impact pressure at the crest wall. For the waves with longer wave periods, less air wave entrained and the wave structure followed a flip-through mode (Cooker and Peregrine, 1991), resulting in an abrupt increase of the impact pressure.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.35 no.2
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• pp.33-40
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• 2023

Wave overtopping rate is one of the most important design parameters for coastal structures. In this study, the physical model tests for measuring the wave overtopping have been conducted with the foreshore slope in front of the seawall. The bottom seabed for the coastal road area was fabricated at the wave flume for two areas in the East sea areas. The wave overtopping rate was measured for various water depths and wave conditions in each coastal area. In particular, the impulsive wave conditions were compared with the previous research and the similar trends of wave overtopping was observed. It could be known that the effect of foreshore slope was significant and should be concerned for applying theses formula like EurOtop.

• The Journal of Engineering Geology
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• v.9 no.2
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• pp.161-176
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• 1999

The objectives of this study are to analyze the changes of geo-surface topography in the Siwha embankment and the Ahsan city area by the image processing of Landsat Thematic Mapper data, and to estimate the reclaimed amount of the exposed tidal flat in the Siwha area using the GIS. False color composite, Tasseled cap, NVDI(normalized difference vegetation index), and supervised classification techniques were used to analyze the distribution of sediments and the aspect of topographical variations caused by artificial human actions. The total amount of the exposed tidal flat was estimated on the basis of the database snch as aerial photography, hydrographic chart, geological map, and scheme drawing in the Siwha area. The possible excavation regions for a seawall were predicted analyzing the supervised classification image of Landsat TM data. Tasseled cap images were used to observe the distribution of sediments. The difference of the NDVI images between spring and summer seasons indicates that deciduous and coniferous forests were distributed over the whole areas. The total fill-volume of the exposed Siwha tidal flat and the fill-volume of the construction planning seawall were calculated as $581,485,354\textrm{m}^3{\;}and{\;}3,387,360\textrm{m}^3$, respectively, from the digital terrain analysis. Daebu Island, Sunkam Island, and the part of Songsan-myeon were chosen as the cut area to make the seawall, and their cut-volumes were estimated as $5,229,576\textrm{m}^3,{\;}79,227,072\textrm{m}^3,{\;}and{\;}47,026,008\textrm{m}^3$, respectively. Therefore, the cut-volume of Daebu Island alone among three areas was sufficient to make the seawall.