• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.49-52
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• 2008

The plain and simple shape water front structure were designed and installed for wave protection and wave resistance. But the installation of these plain and simple structure cause deficiency of environmental affinity. Also the resonance phenomena from the reflective wave and shipwave of the harbor incident wave caused high tide and wave, consequently maintaining the tranquility of inside harbor, give difficulty for mooring the ship and loading-unloading, increase the possibility of ship collision at the quray wall and landing place To solve these problems, we develop the environmentally friendly wave dissipation block. And installation efficiency, stability of the blocks through experiment of C.E Block Joint.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.111-118
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• 2013

This paper suggested the improvement of marine environmental impact assessment in eastern coast as analyzing consultation on the coastal area utilization for development of ports and fishing harbors for 3years in the east coast. The results of survey are only 3cases, 12cases and 16cases each for ocean currents, wave and sounding data. However, for development of ports and fishing harbors in eastern coast, ocean characteristics in eastern coast different than in the West Sea, South Sea is considered to marine environmental impact assessment. For development of ports and fishing harbors in east coast where the influences of ocean currents, wind-driven current and waves are dominant, the effect of the current should be considered to improve the reproducibility of tidal current. The wave should also be considered as an assessment criteria to obtain the validity of project such as harbor tranquility, functionality of breakwaters and stability. In addition, sediment inflow in river and exact water depth data of the ocean should be applied to numerical modeling and set wave-induced current to external force of sediment transport to predict the problems such as the harbor siltation and the coastal erosion considering ocean characteristics in the east coast.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.4
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• pp.180-188
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• 2017

Recently, as the strength of winds and waves increases due to the climate change, abnormal waves such as swells have been also increased, which results in the increase of downtime events of loading/unloading in a harbour. To reduce the downtime events, breakwaters were constructed in a harbour to improve the tranquility. However, it is also important and useful for efficient port operation by predicting accurately and also quickly the downtime events when the harbour operation is in a limiting condition. In this study, numerical simulations were carried out to calculate the wave conditions based on the forecasted wind data in offshore area/outside harbour and also the long-term observation was carried out to obtain the wave data in a harbour. A forecasting method was designed using an auto-regressive (AR) and artificial neural networks (ANN) models in order to establish the relationship between the wave conditions calculated by wave model (SWAN) in offshore area and observed ones in a harbour. To evaluate the applicability of the proposed method, this method was applied to predict wave heights in a harbour and to forecast the downtime events in Pohang New Harbour with highly complex topography were compared. From the verification study, it was observed that the ANN model was more accurate than the AR model.

• Journal of Navigation and Port Research
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• v.34 no.1
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• pp.51-57
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• 2010

When estimating the calmness in a harbor, it is important that diffraction and reflection of irregular waves should be exactly calculated. The basic equation of the numerical model in this study was used Mild-slope equation, which has the advantage of which non-linearity with great influence for the wave behavior can be considered, and a triangular mesh was generated by using finite element method. So as to verify the nonlinear effects, the results of the numerical model developed in this study are compared with the experimental and numerical results by other researchers. As a result, it is shown that the results in case of considering nonlinear wave are more exact for wave analysis than in case of not considering nonlinear wave. In order to apply this model, wave height distributions in Jumunjin fishery port installed a seawater-exchange breakwater are computed. From the results of this numerical analysis, when abnormal waves are intruded through the seawater-exchange breakwater, the results of the wave height distributions in the harbor are highly presented. Therefore, in order to get wave height low in the harbor, it is considered that the facility with the ability to protect the inflow of abnormal waves is needed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.6 s.58
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• pp.176-182
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• 2009

Other damage can occur due to the preexisting dull structure and installation of nonenvironmental-friendly concrete structure, lack of function for preventing coastal erosion. Increase of personal income and fast spread of the concept of waterfront casued the initiation of many project to improve aging coastal ports. However, none of environment-friendly structure has been developed and pre-existing solid block, igloo block, tunnel block are used commonly. In piers and lighter's wharf where the ships are mooring, resonance by the generation of a reflected wave caused by penetration wave in the port and port wave increases wave heights in the port and makes difficult to maintain the temperature, causes problems in mooring ships and cargo-working, and eventually increase the occurance of damages of the small ships by the collision. Therefore, development of new types of blcok is necessary. To apply Coastal Environments block developed for this reason, it requires allowable bearing capacity evaluation of shear key. For this study, we made test specimen for connecting part of C.E. Block, and conducted friction test of boundary surface. Data obtained by the experiment was analyzed by finite element analysis and assessed the coefficient of friction between C.E. Block and boundary surface.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.703-707
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• 2009

In order to evaluate applicability of cylindrical slit type block breakwater to the field water, which was designed from the previous physical model study, it is analyzed the calmness of harbor area by the numerical model experiment. For a small fishery port in southern coast of Korea a SWAN model using the wave action balance equation was formulated. The reflection and transmission coefficients induced by the physical model test were introduced to the numerical model. The model response with cylindrical slit type breakwater was compared with the impermeable breakwater case and the possibility of water quality improvement through the water circulation by the new structure was investigated. For numerical simulation, parameters of deepwater design wave from the prediction report II for overall deepwater design wave by KORDI were used and wind parameters from the 50years return period observed for 37years(1970~2006) were adopted in the numerical model. The response of west breakwater in Mijo port applying the NE and NNE waves, which were dominant in this area, was analyzed. It was found that the transmission characteristic of designed cylindrical slit breakwater was well presented in the numerical model.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.3
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• pp.154-164
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• 2013

In this study, a new type floating breakwater was proposed to improve the capability of wave attenuation compared with the existing floating breakwater in Wonjun Port, which is located in Masan City, Korea. In order to develop the optimal design, many different configurations considering the shape and location of vertical barrier and horizontal plate were examined based on the shape of existing floating breakwaters in Wonjun and Tongyeong Port. The analytical and numerical results of the new type floating breakwater showed better performance in long-period wave attenuation than the existing floating breakwater in Wonjun. Therefore, the new type floating breakwater can improve harbor tranquility in Wonjun Port.

• Journal of the Korean Geotechnical Society
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• v.27 no.12
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• pp.85-96
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• 2011

A breakwater is a important structure for both calmness of harbor and protection of the port facilities from waves generated from typhoons or wind. This study adopted the rubble mound breakwater, which is one of the most popular type of breakwaters in Korea. Rubble mound breakwater had been designed by considering only static condition previously. Recently, a dynamic wave-load due to waves has been also considered in designing breakwater. In design, the wave-load is assumed as an uniform load which only acts in the front slope of the breakwater. However, the assumption is not applicable in reality. In this study, therefore, a real-time wave-load acting on the breakwater instead of the uniform load is considered, and it is assumed to be acting on the seabed too. Based on the numerical analysis, it is found that there is a significant difference in the maximum settlement compared with the result predicted by the existing design method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.141-142
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• 2007

In recent years, the rate of mean sea level rise is increasing rapidly from the phenomena of global warming, together with the increasing trend of the storm scale. The issue of sea level rise is multifaceted and produces a range of environmental problems. Especially, high tides and the tidal currents become higher, and wave base increases, so the energy received at the coastal boundary may increase. This brings that many coastal environments go into disequilibrium, such as damages to the structures, erosion, and deposition Similarly it was known that the problems of nearshore processes and damage of berth and counter facilities during storm period had appeared at the small fishery port. Here we try to analyze the impact of the rearrangement of counter facilities and berth layout adopted for tranquility of its'inner harbor. Because this harbor is being connected to channel and open sea, the rearrangement of the structures might affect to the current speed and direction and wave height, so do to the sea bottom undulation. Therefore, we made model test for the several layouts of the berth and breakwater in this area.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.57-62
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• 2006

Busan New Port, under construction aiming for the hub of Northeast Asia and Partly in operation, had damaged up to 48 billion Won due to Typhoon 'maemi' in 2003. The present criteria of domestic harbor design only describes about the critical wave height with respect to the size of vessel for harbor tranquility. The berth operation ratio which represents the annual available berthing days is depending on the efficiency of cargo handling work and this depends on the motion of the moored vessel due to the wave action and the characteristics of cargo gears. The motion of moored vessel might be related not only to the wave height but also to wave period. Furthermore, the berth operation ratio relies on external forces such as currents and winds, including the characteristics of mooring system and the specification of the moored vessel. In this study we only deal with berth operation ratio in normal sea state, considering wave and current by measured data and numerical calculation. Especially we tried to evaluate the berth operation ratio for each berth adopting the variation of dredging and reclamation plan and the change of wave environment during the process of the new port construction. For better understanding and analysis of wave transformation process, we applied the steady state spectral wave model and extended mild-slope wave model to the related site. This study summarizes comparisons of harbor responses predicted by two numerical predictions obtained at Busan New port site. Field and numerical model analysis was conducted for the original port plan and the final corrected plan.