• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.4
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• pp.318-328
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• 1993

A series of long wave measurements was made in the region of Shikotan Island (the South Kuril Islands) during 1990-1992: 7 bottom pressure stations were installed in 5 bays and inlets of Shikotan and 3 precise microbarographs were situated at the shore. The observations were taken in order to monitor tsunami waves, estimate resonance features of coastal topography, and investigate seiche generation mechanism. It was found that forced long waves dominate in the motions with periods exceeding 2 hours, freely propagating long waves prevail at periods of 30-120 min and eigen-oscillations of bays (seiches) are the predominant type of long waves at periods less than 30 min. The Helmholtz mode with period 30 min in Krabovaya Bay and 18.5 min in Malokurilskaya Bay is the most important type of wave motion in the inner Shikotan basins. There is a good correlation between passages of atmospheric disturbances and generation of seiches near the coast of Shikotan Island. In particular, jumps in atmospheric pressure excite seiches in different bays simultaneously, in each one with the corresponding dominant period. The atmospheric spectra were remarkably smooth and stable, and could be described by a $\omega$$^{-2}$26/ power law.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1992.08a
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• pp.23-27
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• 1992

대형선박이 접안하여 하역작업을 수행하는 동해안의 산업항중 포항신항에서는 과거의 연구나 한국해양연구소의 현장관측(건설부, 1987; 강 등, 1989)을 통하여 다양한 주기의 부진동이 존재함이 밝혀졌으며, 검조소가 없는 동해항의 인근에 위치한 묵호항의 검조기록을 검토한 결과 10분대의 장주기 부진동이 존재하는 것으로 나타났다.(중략)

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1992.08a
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• pp.28-28
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• 1992

우리 나라 주요항만의 해면 부진동 현상은 일반적인 파랑 보다 주기가 긴 수분 - 수십분의 주기를 갖는 항만고유의 자유진동으로서 폭풍해일 또는 지진 해일과 밀접한 관계가 있으며 장주기파의 Energy 가 항만내에 크게 영향을 미치는 것을 고려 할때 항만건설, 유지를 위한 설계, 선박의 계류, 묘박지의 정온도, 해난사고 및 화재 방지상 대단히 중요시 되어야 할 요소이다.(중략)

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.6 no.4
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• pp.452-458
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• 1994

The advantage of tide-well system with an intake pipe near the sea floor is that it can record not only tide but also harbour oscillation. tsunami. rapid change of tide height when a storm was causing rapid fluctuations in sea level. Consequently record of harbour oscillation may be extracted from tidal records by removing the predicted tide and then correcting for the attenuation caused by the tide-well system. The response of tide-well with intake pipe to seiche was examined by in situ measurements for Mukho tidal station. The well constant was also computed hydraulically on the basis of the structure of the tide gage system. It has been found that the response coefficient of the Mukho tidal station was 0.01. The tide records can be used for the determination of mean sea levels for surveying purposes. as the response of tide-well system can be estimated.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1996.10a
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• pp.184-187
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• 1996

기존의 항만 부진동현상 해석은 대부분 완전유체라는 가정하에 선형이론에 기초하여 개발된 수치 모델에 의해 수행되고 있다. 실제의 경우에는 해저면의 마찰, 고체경계면을 따른 에너지 손실, 단면의 급 축소 및 확대에 따른 에너지 손실 등이 존재하므로, 이와 같은 에너지의 손실을 고려하지 않고 선형해석을 수행하게 되면 실제와는 다른 과장된 결과를 얻게 된다. 특히, 항 입구의 폭이 좁은 경우에는 실제와는 다르게 증폭비가 대단히 크게 예측된다. (중략)

• 한국해양학회지
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• v.11 no.2
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• pp.51-56
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• 1976

A statistcal investigation was made on the seiches at Pohang harbor, east of Korea, based on the data of observations for the year 1973 and 1974. Pohang harbor has a most remarkable seiches comparing to the major harbors in Korea. The frequently observed conspicuos seiches at the harbor have a period of 20 to 24 minutes mostly and 60 to 84 minutes in the next place. Maximum height of seiches were 50cm in 1973 and 60cm in 1974, respectively, which were occured at the expansions of cold-dry continental high pressure and on the following day of passages of lowest pressurs. Minus tides at Pohang were occured more frequently than that of seiches and the minus tides falled more greatly at the time of seiches.

• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.533-539
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• 2006

Today the harbor oscillation problems are the most significant factor to design harbors serving the very large ships. Large vessels moored in the elastic hawsers at the coastal harbors are often displaced due to the resonance between the long period waves and mooring system. The cargo handling may be interrupted and the hawsers may be broken, especially when the amplification becomes remarkable. The most significant harbor which is confronted with harbor oscillation problem in Korea is the Pohang New Port. Many cases of problems are being notified by the pilot association and local office of MOMAF. However, it is difficult to prevent the arrival of long waves musing oscillation within this harbor. Moreover, government already started new port plan at the mouth of Yeongil Bay without treating problems occurred in the Pohang New Port. This study deals with the variation of harbor oscillation due to the construction of 4.1km breakwater at the bay mouth and new port plan. Numerical method used are fairly standard form from the extended mild slope equation The obtained numerical results were compared with the field measurement from the previous study and this will bring a certain level of discussion and consideration of variation in the future port development.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.124-126
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• 2016

해안역에서의 대규모 개발은 파랑에너지의 전파에 상당한 변화를 초래한다. 특히, 항만내로 전파되는 파랑장을 변화시켜 기존의 에너지 전달체계에 큰 영향을 야기한다. 따라서, 이러한 파랑에너지의 변화를 사전에 예측하여 항만내의 선박이나 항만구조물의 피해를 막을 수 있다. 그러나 일반적으로 수행되는 항만내의 파랑장 검토 즉, 정온도 검토는 주로 공학적으로 문제가 되는 주기 10~20sec의 풍파와 너울성 파랑에 대하여 수행되고 있다. 그러나 실제 현장에서는 20sec 이상의 장주기 파랑에 의한 선박이나 항만구조물에 상당한 피해를 가져오기도 하지만 이로 인해 연간 부두 접안율이 낮아 항만운영에 어려움을 겪고 있다. 본 실험은 대규모 개발에 따른 장주기 파랑에 의한 반응특성과 부진동의 영향을 검토하였다. 특히, 항내 수제선에 개발이 집중적으로 이루어져 내륙측으로 항만수역을 보완하거나 변경이 어려운 경우 장주기파로 인한 부진동의 영향을 저감하기 위한 시도로 공진수역을 도입하였으며, 이에 대한 반응 특성을 분석하여 장래 항만 재배치 계획에 반영할 수 있는 근거가 될 수 있을 것으로 본다.

• Journal of Ocean Engineering and Technology
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• v.16 no.2
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• pp.27-31
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• 2002

The purpose of this study is to investigate the variation of resonance that is possible caused by construction of new port in a practical sea area between the existing port and the new one. The research of amplification that of the sea area was accomplished for the variation of resonance. In this study, long period wave that is observed continuously in the practical sea area was analyzed, and then secondary undulation was reproduced by numerical analysis. As a result of numerical analysis, the first mode resonant periods in the existing port is 640sec, and in the new one is 500sec. On the other hand, we know there is long period wave of 500sec from analyzation of field datas. Because that period this period is the resonant period in the new port. There is also the possibility of secondary undulation cause of resonant.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.1
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• pp.58-65
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• 2012

In this study, to reduce the motion of the vessels resulting from resonance and secondary undulation by long-period waves, numerical review on the control performance of resonator was carried out by attaching the resonator to the established harbor of real waters. In the numerical analysis, CGWAVE MODULE of commercial software SMS(Surface water Modeling System), a finite element model based on 2-dimensional elliptical mild slope equation was applied, and through comparative analysis of the existing experiments and analysis results on the rectangular model ports, the validity of the friction coefficients in which validity and effectiveness of SMS on the secondary undulation analysis is applied was verified. Based on this, the control performance of resonator was confirmed through comparative review of the secondary undulation according to whether or not to attach the resonator to rectangular harbor. In addition, to reduce long-period motion of the moored vessels and the secondary undulation which may occur in Pohang new port, the method to move the resonant period which causes abnormal motion of the vessels to long-term one was discussed through application of the resonators with various sizes, thereby identifying the availability.