• Journal of Ocean Engineering and Technology
• /
• v.33 no.3
• /
• pp.280-288
• /
• 2019

A submerged breakwater is one of the coastal structures used to reduce wave energy and coastal erosion. However, a submerged breakwater has a negative aspect in that a strong rip current occurring around an open inlet due to a difference in mean water levels at the front and rear sides of the structure leads to scouring. Such scouring has a bad effect on its stability. In order to eliminate this kind of demerit, this study investigated an artificial reef of the overflow type with openings. We also developed a program where the flows around the artificial reef of the overflow type could be analyzed numerically. An unstructured grid system was used to cover the various geometries, and the level set method was applied to treat the movement of the free surface. To verify these numerical schemes, hydraulic physical tests were performed on the submerged breakwater and double breaking type artificial reef. Then, the wave height and velocity distribution around the reef were examined using the experimental results. Comparisons between the results of hydraulic and numerical tests showed reasonable agreement.

• Journal of Korea Water Resources Association
• /
• v.36 no.4
• /
• pp.623-631
• /
• 2003

A large scale hydrological laboratory model tests for the geotextile tube were conducted to investigate the stability of geotextile tube and the capability of breakwater with variations of significant wave height, percentage of soil filling, and the water level above geotextile tube. The sliding displacement of geotextile tube is measured to check the stability of geotextile tube for given the various significant wane heights. The marked mash was laid out at the bottom of water channel to measure the displacement of geotextile tube. The bench mark was furnished in the upper part of water channel and the initial location was marked every 10cm interval to measure the displacement of geotextile tube. The wane transmit ratios are analyzed with the variations of soil filling of tube and of the top crown height wave above the geotextile tube in order to study the performance of brekwater before and after the installation of geotextile tube.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.20 no.6
• /
• pp.602-610
• /
• 2008

A beach has such functions as disaster prevention, providing an amenity place, attracting people and maintaining the coastal ecosystem. Already well known that a beach provides an amenity place, it has also been ascertained through various examples that a sand beach performs a very important function to maintain the coastal ecosystem as well. However, Beach erosion began to occur in Korea in the 1990's and posed a social problem in the late 1990's. Nowadays, along the shorelines of Korea's many beaches, about 400 beaches have reported erosion. This study demonstrate the Disaster Overall Prevention System for Beach Erosion and it's application. The Disaster Overall Prevention System for Beach Erosion is a coastal management system established for managing the implementation of long-term countermeasures to protect eroded beaches effectively in this study. Especially, the economic feasibility test and adaptive management for sustainable mitigation included in DOPS. The coastal prevention work applied to Namae beach is carried out by Disaster Overall Prevention System. Consequently, beach nourishment is proposed as a main countermeasure. Also, submerged artificial reefs and groin integrating artificial rock are proposed as secondary countermeasures for beach erosion. This resulted to be the optimal beach erosion countermeasure from DOPS, considering the economic and environmental conditions of the study area.