• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.1
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• pp.119-128
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• 2015

This study investigates the wave pressure characteristics of the pile-supported breakwater with single or double perforated walls through 2-D hydraulic experiments and the measured wave pressures are compared to those of wave pressures by Goda's formula. For single chamber, the measured wave pressures in the front wall and rear wall decreased to about 25% and 30%, respectively, compared to those of wave pressures by Goda's formula. Also, the decrease in the wave pressures for double chamber were about 27%, 53%, and 64% in the front wall, middle wall, and rear wall, respectively. It was found that the pile-supported breakwater with double perforated walls was more efficient than the single chamber due to wave dissipation effects of double slit walls with horizontal slits.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.4
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• pp.469-480
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• 2022

To design the crown wall of rubble-mound breakwaters, the horizontal wave load should be available, but determining this load remains difficult. Lee et al. proposed modification factors for Goda's formula for the horizontal wave pressures on acrown wall. The empirical formula by Lee et al. was based on a two-dimensional model test with a relatively narrow armour crest width in front of the crown wall. In this study, a series of experiments at the same facility were conducted on the horizontal wave pressures on the crown wall of a rubble-mound breakwater with a wide armour crest width. As a result, the pressures of the unprotected part of the crown wall were nearly identical to the narrow crest width. However, the pressures of the protected part tended to decrease with a change in the armour crest width. From the experimental results, the horizontal pressure modification factors of Goda's formula including the armour crest width effect are suggested here and are likely applicable to practical designs of the crown walls of rubble-mound breakwaters covered with tetrapods.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.64.1-64.1
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• 2010

국내 지진해일에 관한 연구 중, 구조물에 직접적인 영향을 미치는 파력에 대한 연구가 현재 미미한 실정이다. 본 연구에서는 파고와 입사각, 그리고 유의주기를 기지값으로 하여 파압을 계산하는 Goda(1974)가 제안한 파압공식을 이용하여 파압을 산정하였다. 파고는 Cho(1995) 모델로 산정하였으며 이를 임원항구의 방파제에 적용하였다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.3
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• pp.82-92
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• 2022

In recent years, coastal and port structures have attempted to prevent wave-overtopping or provide waterfront areas by installing superstructures on the structural crowns. In general, in the design stage, the Goda formula acting on the front the structure is applied to calculate the wave pressure acting on the superstructure in consideration of the wave-runup of the design wave. However, the wave pressure exceeding the Goda wave pressure could generate depending on the installation location of the superstructure where the wave-overtopping occurs. This study analyzed the applicability of the Goda formula to the wave pressure calculation for the superstructure of the vertical structures through hydraulic model experiments and numerical simulations. Furthermore, this study investigated the magnitude of the wave pressure acting on the superstructure based on detailed numerical results. As a result, the wave pressure acting on the superstructure was up to 120% higher than the maximum wave pressure on the still water surface. In addition, the wave pressure increases exponentially with the Froude number computed by the overtopping water depth at the crown of the structure, and we proposed an empirical formula for predicting the wave pressure based on the Froude number.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.484-489
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• 2004

경사식 방파제에 대하여 수리모형실험을 통하여 방파제의 전사면과 저면에 작용하는 파압을 직접 측정하여 파압의 공간적 분포를 파악하여 보았다. 실험의 길과는 기존의 경사식 방파제에 대하여 파압에 대한 연구는 거의 없기 때문에 Goda(1989, 2002)가 제시한 전사면에 대한 이론식과 비교하여 보았다. 실험은 특정적으로 제시된 방파제 단면에 대한 실험이 아니고, 가상적인 단면을 선정한 후 파랑 및 수심 등의 제조건을 감안하여 파형경사를 산정하고, 이애 맞는 파고와 주기를 산정한 후 제반 해안수리학적 특성중 반사율과 처오름 높이, 사면 및 저면에 작용하는 파압을 직접 측정하여 보았다. 실험결과 전사면에서의 파압 분포는 Goda의 이론식과 경향은 비슷하나 크기는 차이가 나이에 대한 보정은 필요한 것으로 나타났으며, 저면에서의 파압도 측정이 되었지만 이것이 지반지지력에 어떠한 영향을 미치는지는 좀 더 많은 연구가 필요할 것으로 판단되었다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.321-332
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• 2021

The crown wall with parapet on top of the rubble mound breakwater represents a relatively economic and efficient solution to reduce the wave overtopping discharge. However, the inclusion of parapet leads to increased wave pressure on the crown wall. The wave pressure on the crown wall is investigated by physical model test. To design the crown wall the wave loads should be available, and the horizontal wave pressure is still unclear. Regarding to the horizontal wave pressure on the crown wall, a series of experiments were conducted by changing the rubble mound type structure and the wave conditions. Based on these results, pressure modification factors of Goda's (1974, 2010) formula have been suggested, which can be applicable for the practical design of the crown wall of the rubble-mound breakwater covered by tetrapods.

• Journal of Ocean Engineering and Technology
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• v.15 no.3
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• pp.114-119
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• 2001

Goda formula (Goda, 1973) has been used in the determination of wave pressures acting on a large size caisson such as the pier of the cable stayed bridge at sea. Goda formula, however, is to evaluate the wave pressures acting the infinite vertical caisson of composite breakwater so that it can`t be applied to a large caisson with finite width and length because of diffraction effects. In the present study, three dimensional nonlinear frequence domain method based on perturbation method and boundary integral method is applied to the computation of the linear and nonlinear wave pressures acting on the front of a large size caisson under the variation of its width and length, and angle of incident wave. The numerical results are compared to Goda\`s ones, and then the characteristics of wave pressure distributions acting on a large size caisson are discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.573-584
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• 2013

This study experimentally investigated the change in distribution of wave pressure on the front wall according to the variation of the front wall porosity of the caisson breakwater having the cap of wave chamber. First, the wave pressure for the non-porous caissson corresponding to zero porosity was measured and compared with the pressure formula suggested by Goda(1974). The analysis showed that the measured pressure distribution fairly well agreed with the Goda formula, which confirmed the accurate measurement of wave pressure in the present experiment. In case of the porous caisson, meanwhile, the experiment was performed by varying the front wall porosity as 0.2, 0.25, and 0.3. The wave pressure distribution at the front wall showed little difference according to the porosity for most of the test wave conditions, whereas the pressure slightly increased with the porosity for some test waves whose wave heights and periods were relatively large. However, the difference according to the porsosity was insignificant for the wave force at the front wall.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1992.08a
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• pp.130-134
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• 1992

본 연구의 목표는 혼성방파제의 무공 및 유공 케이슨에 작용하는 파압분포에 대한 기존의 연구결과를 조사, 분석, 정리하고 실제로 이들에 대한 수리모형실험을 실시하여 관측된 결과를 기존의 연구결과(곡본승리 등 1982, 고교중웅 등 1983, Goda 1985, Takahashi 1991)와 비교, 분석함으로써 케이슨에 작용하는 파압은 물론 기타 수리현상의 특성을 파악하는 데 있다.(중략)

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.183-186
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• 2011

해양구조물은 다양한 외력으로부터 지속적인 영향을 받으며 특히, 파력은 구조물의 설계에 결정적인 인자로 간주된다. 해양구조물 파장과 구조물의 크기와의 상대적인 관계로부터 크게 소형구조물, 대형구조물, 대상구조물로 대별될 수 있다. 전통적으로 소형구조물은 회절파의 발생이 없는 것으로 가정하여 Morison식으로부터 파력을 산정하고, 대형구조물은 회절파의 작용에 따른 관성력만을 고려하며, 대상구조물은 단면 2차원적인 파압만을 고려하여 Goda파압공식류로부터 작용파압을 추정하고 있다. 이러한 평가는 단주기파랑의 작용에 근거를 두고 있고, 또 대형 및 대상구조물의 경우에는 유체의 점성력을 고려하고 있지 않으며, 특히 지진해일파의 작용에 대한 평가는 전혀 이루어지지 않는 것이 현재의 상태이다. 본 연구는 대형구조물인 슬리트케이슨과 소형 구조물인 자켓구조물을 대상구조물로 선정하여 구조해석을 토대로 파랑의 변화에 따른 구조물의 거동특성을 연구하였다.