• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.79.1-79.1
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• 2010

본 연구에서는 케이슨식 방파제 구조물에 대하여 기초마운드의 잠재적인 손상 모니터링에 관한 연구를 수행하였다. 이를 위해 첫째, 케이슨식 방파제 기초마운드의 이상 상태 여부를 판단하기 위하여 진동응답 분석기법을 선정하였다. 둘째, 선정된 기법에 의한 손상 예측 가능성의 검증을 위하여 케이슨식 방파제의 구조모형을 제작하였다. 셋째, 모형케이슨에 대한 유한요소 모델 생생하여 기초마운드의 손상에 따른 진동응답을 분석하였다. 마지막으로, 모형케이슨에 대한 진동실험을 통하여 기초마운드의 손상 예측을 수행하였다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.145-148
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• 2010

항만 구조물의 건전성 평가 기술의 개발을 위한 기초 연구로서, 강제진동해석을 통하여 케이슨 구조-지반 경계부의 손상에 대한 진동응답을 분석하고자 한다. 이를 위해 세 단계의 연구를 수행하였다. 첫째, 케이슨 구조물의 진동특성 분석을 위해 시간영역기반의 AR(auto-regressive)모델을 선정하였다. 둘째, 모형 케이슨 구조물을 대상으로 진동응답 계측실험을 수행하였으며, AR-모델을 통해 진동특징을 실험적으로 분석하였다. 셋째, 대상 케이슨 시스템의 유한요소모델을 구성하고, 구조-지반 경계부의 손상에 따른 동적응답 특성의 변화를 수치적으로 분석하였다. 이를 위해 강제진동을 모사 하였으며, 구조-지반 경계부의 강성변화에 따른 케이슨 구조물의 진동응답의 변화를 분석하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.195-201
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• 2019

Long caisson breakwaters can improve the structural safety of a caisson due to the wave dispersion effect which reduces the average wave force acting on one caisson. However, in order to make long caissons, there are many manufacturing and construction limitations. Recently, interlocking caisson systems, which are to form a long caisson by interlocking individual caissons with adjacent caissons, have been much attention. In the present study, a interlocking caisson system with shear-keys was proposed and the wave dispersion effect according to the shear-key was evaluated analytically. As a result, (1) Because of the asymmetric shape of the interlocking caisson, the structure behavior and the wave dispersion effect of one are also asymmetric. (2) The wave dispersion effect is more influenced by the distribution and characteristics of wave acting on each caisson rather than the shape of the shear-key such as shear angle, height, shear length ratio. (3) The interlocking caisson breakwater is almost the same behavior and wave dispersion effect as a fully integrated breakwater.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.4
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• pp.213-220
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• 2005

An approach to calculate expected sliding distance of wave dissipating caisson breakwater is proposed. Time history of dynamic wave pressure for the calculation of sliding distance is made by extending conventional static wave pressure developed for the wave dissipating caisson breakwater. Construction of impact wave and standing wave was done by using duration time and maximum wave pressures of themselves. In the numerical analysis, the sliding distance for an attack of single wave and expected sliding distance for 50 years of wave dissipating breakwater by proposed method were compared with those by conventional method for uplift caisson breakwater. It was found that the sliding distance of wave dissipating breakwater by the proposed method is smaller than by conventional method.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.6
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• pp.420-433
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• 2020

In order to increase the stability of existing breakwater, new caissons are installed on the back or the front of existing caissons. It is very important to evaluate wave force and wave run-up according to the change of porosity among caissons and the energy loss due to separation effects. In this study, we use the eigenfunction expansion method with Darcy's law, which describes the flow of a fluid through a porous plate, to analyze the characteristics of wave on circular breakwater of double array for various porous coefficients. To verify the numerical method, the comparison between present results and Sankarbabu et al. (2008) is made. The wave force and the wave run-up acting on each dual cylindrical caisson are calculated for various parameters by considering the energy loss and the change of porosity.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2C
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• pp.105-115
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• 2008

The records of field instrumentation, which have been performed on the pneumatic caisson used for substructure of the Youngjong Grand Bridge, were analyzed to investigate the ground contact pressure under rigid foundation of large pneumatic caisson embedded in various ground layers. During sinking the pneumatic caisson, the resisting force was mobilized against sinking the caisson at the contact area between bottom of the caisson and the ground. The resisting force could be measured by the reaction force gauges instrumented under the edge of bottom of the pneumatic caisson. And the ground contact pressure could be estimated by use of the measuring records of the resisting force. The ground contact pressure under rigid foundation of large pneumatic caisson shows concave distribution on bedrock, while convex distribution was shown in marine deposit soil layer as well as weathered rock layer. And, the ground contact pressure in various ground layers was distributed axis-symmetrically. The distribution shape of the ground contact pressure determined by the maximum pressure acting on foundation of the large pneumatic caisson showed good coincidence with the distribution shape proposed for rigid foundation by Kgler(1936) and Fang(1991).

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1454-1458
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• 2004

본 인구에서는 직립 유공 케이슨에 현수판을 설치함으로서 입사파의 반사율을 저감시키고자 하였다. 먼저 케이슨 단면의 적정 유공율을 선정하기 위해 횡 SLIT 케이슨식 2개안 및 종 SLIT 1개안 단면에 대한 단면 실험을 실시하였다. 선행된 실험에서 가장 반사율이 낮은 SLIT 케이슨을 선택하여 유수실에 현수판을 설치 하였으며 현수판의 설치유무 및 현수판의 길이에 따른 반사계수를 검토하였다. 설치된 현수판은 장주기파에 대해서 반사율 저감효과를 얻을 수 없었지만 단주기 파에서는 반사율이 줄어드는 효과를 얻을 수 있었다. 해역에따라 단주기가 주류를 이루는 해역에서 현수판을 설치하면 파랑내습시 소파효과가 증대될 것으로 기대된다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.606-609
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• 2011

본 연구에서는 실제 케이슨 방파제 구조물의 진동기반 안정성 평가를 위한 기초연구로서, 현장실험을 통해 케이슨 방파제 구조물의 진동응답을 분석하였다. 이를 위해 첫째, 대상구조물로서 부산항 오륙도 케이슨 방파제를 선정하였다. 둘째, 파랑에 의한 상시진동 가속도응답을 계측하였다. 마지막으로, 계측된 가속도신호로부터 파워스펙트럼밀도함수, 고유진동수 및 모드강성도 분석을 통해 케이슨 방파제의 진동특성을 분석하였다.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.88-88
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• 2009

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.6
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• pp.396-410
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• 2020

The design and the construction are carried out by installation of new caissons on the back or the front of existing caissons to increase the stability of existing caisson breakwater. In this study, we use the eigenfunction expansion method to analyze the effects of wave structure interaction when new porous dual circular caissons are installed on the back or the front of existing breakwater. The porous dual circular caisson which consisting of a porous outer cylinder circumscribing an impermeable inner cylinder is one type of seawater exchanging breakwater. The comparison of numerical results between present method and Sankarbabu et al. is made, and the wave force and the wave run-up acting on each porous dual circular caisson are calculated for various parameters by considering the wave structure interaction.