• 한국해안·해양공학회논문집
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• 제32권6호
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• pp.465-480
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• 2020

2012년 남해안에 내습한 태풍 산바에 의해 발생한 폭풍해일과 파랑을 JMA-MSM 예보기상자료, NCEP-CFSR 재분석 기상자료, ECMWF-ERA5 재분석 기상자료, JTWC의 최적경로를 이용한 기상자료를 이용하여 수치모의하고, 계산된 해일고를 전국 해안의 항만에서 관측된 폭풍해일 시계열 자료와 비교하였으며, 파랑에 대해서는 계산된 유의파고를 해상 부이 및 수압식 파고 관측 자료와 비교하였다. 이 비교를 통해 태풍 산바에 대한 각종 기상장의 신뢰도를 평가하였다. 그 결과 JMA-MSM 기상자료와 NCEP-CFSR 기상자료가 가장 신뢰도가 높았고, ECMWF-ERA5 기상자료는 전반적으로 해일고나 파고의 크기가 작게 나타났으나, 태풍 전면부의 수렴대는 가장 잘 재현하는 것으로 나타났다. JTWC의 최적경로를 이용한 기상자료는 신뢰도가 가장 낮게 나타났다.

• Wind and Structures
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• 제30권1호
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• pp.1-13
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• 2020

The loss prediction and assessment during extreme events such as wind hazards is always crucial for the group low-rise residential buildings. This paper analyses the effect of variation in building density on wind-induced loss for low-rise buildings and proposes a loss assessment method consequently. It is based on the damage matrices of the building envelope structures and the main load-bearing structure, which includes the influence factors such as structure type, preservation degree, building density, and interaction between different envelope components. Accordingly, based on field investigation and engineering experience, this study establishes a relevant building direct economic loss assessment model. Finally, the authors develop the Typhoon Disaster Management System to apply this loss assessment methodology to practice.

• 한국환경과학회지
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• 제11권7호
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• pp.627-636
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• 2002

While typhoons were passing by the coastal and offshore waters around the Korean peninsula, the variations of the sea surface temperature (SST) were studied. To study on the variation, the data related to the 22 typhoons among 346 typhoons which occurred in the western Pacific during 1990∼1999, daily measured field SSTs at coastal and offshore, and imageries from advanced very high resolution radiometer on NOAA satellite during 1990∼1999 were used. The average variations of the SSTs were -0.9℃ at coastal waters and -2℃ at offshore around the Korean peninsula while the typhoons were passing by. In very near coastal waters from the land, the SST was not changed because the bottom depth of the coastal waters was shallower than the depth of thermalcline, while the typhoon was passing. The temporal and spatial variation of SSTs at coastal waters in summer were depended on the various types of the typhoons＇paths which were passing through the Korean peninsula. When a typhoon passed by the western parts including the Yellow Sea of the Korean peninsula upwelling cold water occurred along the eastern coastal waters of the peninsula. The reason was estimated with the typhoon that was as very strong wind which blew from south toward north direction along the eastern shore of the peninsula, led to the Ekman transport from near the eastern coastal area toward the offshore. While cold water was occurring in the eastern coast, a typhoon passed over the coastal area, the cold water disappeared. The reason was estimated that the cold water was mixed up with the surrounding warm water by the effect of the typhoon. While a cold water was occurring in the eastern coast, a typhoon passed by the offshore of the eastern coast, there were the increasing of the SST as well as the disappearing of the cold water. While a typhoon was passing by the offshore of the eastern coast, the cold water which resulted from the strong tidal current in the western coast of the peninsula was horizontally spread from the onshore to the offshore. We think that the typhoon played the role of the very strong wind which was blowing from north toward south. Therefore, the Ekman transport occurred from the onshore toward the offshore of the western coast in the Korean peninsula.

• 한국해안·해양공학회논문집
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• 제21권1호
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• pp.63-78
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• 2009

본 논문에서는 천해에 적용 가능한 동적결합형 태풍 해일-조석-파랑 수치모델의 개발과 개발된 모델의 정확성을 검증하였다. 태풍 해일과 조석 수치모델은 POM (Princeton Ocean Model)을 기반으로 하였으며, 풍파 파랑 수치모델은 WAM (Wave Model)을 기반으로 천해에 적용할 수 있도록 수정하여 두 모델을 동적으로 결합하였다. 연속된 두 개의 논문 중에 첫 번째 논문인 본 논문에서는 해일과 조석을 수치 모의하는 해수유동 부분의 수치모의의 안정성과 정확성을 검증하였다. 수치모의의 안정성과 정확성 향상을 위하여 기존의 POM 모델의 난류 수치모델 부분과 연직속도 계산 알고리즘을 수정 보완하였다. 수정된 POM 모델의 정확성과 수치적 안정성 검증을 위하여 해석해와 실 해역에서 측정된 관측결과와 비교하였으며, 수정된 POM 모델이 기존의 POM 모델보다 수치계산의 안정성과 정확성이 개선되었음을 확인할 수 있었다.

• Wind and Structures
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• 제25권2호
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• pp.195-214
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• 2017

Full-scale wind characteristics based on the field measurements is an essential element in structural wind engineering. Statistical analysis of the wind characteristics at Sutong Cable-stayed Bridge (SCB) site is conducted in this study with the recorded long-term wind data from structural health monitoring system (SHMS) between 2008 and 2015. Both the mean and turbulent wind characteristics and power spectra are comprehensively investigated and compared with those in the current codes of practice, such as the measured wind rose diagram, monthly maximum mean wind speed, turbulence intensity, integral length scale. Measurement results based on the monitoring data show that winds surrounding the SCB site are substantially influenced by the southeast monsoon in summer and strong northern wind in winter. The measured turbulence intensity is slightly higher than the recommended values in specifications, while the measured ratio of lateral to longitudinal turbulence intensity is slightly lower. An approximately linear relationship between the measured turbulence intensities and gust factors is obtained. The mean value of the turbulence integral length scale is smaller than that of typical typhoon events. In addition, it is found that the Kaimal spectrum is suitable to be adopted as the power spectrum for longitudinal wind component at the SCB site. This contribution would provide important wind characteristic references for the wind performance evaluation of SCB and other civil infrastructures in adjacent regions.

• 한국해안·해양공학회논문집
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• 제32권4호
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• pp.252-261
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• 2020

2018년 남해안에 내습한 태풍 콩레이에 의해 발생한 폭풍해일과 파랑을 일본 기상청의 기상자료인 JMA-MSM 기상 예보 자료를 이용하여 수치모의하고 남동 해안의 항만에서 관측된 폭풍해일 시계열 자료와 비교 검증하였다. 폭풍해일과 동시에 발생하는 파랑에 대해서는 국립해양조사원과 기상청에서 운영하는 해상 파고부이 자료 및 한국해양과학기술원에서 관측한 연안 AWAC 파고계 자료와 비교하여 검증하였다. 기상자료에 따른 폭풍해일과 파랑의 정밀도를 파악하기 위해 미국 합동태풍경보센터인 JTWC에서 제공하는 best track을 이용하여 생성된 기압장과 바람장을 이용한 수치모의를 수행하고 비교 분석하였다. 이 연구를 통하여 정도 높은 폭풍해일과 파랑을 추산하기 위해 신뢰도 높은 기상장이 필수적임을 알 수 있었다.

• Wind and Structures
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• 제13권6호
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• pp.557-580
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• 2010

A new inflow turbulence generation method and a combined dynamic SGS model recently developed by the authors were applied to evaluate the wind effects on 508 m high Taipei 101 Tower. Unlike the majority of the past studies on large eddy simulation (LES) of wind effects on tall buildings, the present numerical simulations were conducted for the full-scale tall building with Reynolds number greater than $10^8$. The inflow turbulent flow field was generated based on the new method called discretizing and synthesizing of random flow generation technique (DSRFG) with a prominent feature that the generated wind velocity fluctuations satisfy any target spectrum and target profiles of turbulence intensity and turbulence integral length scale. The new dynamic SGS model takes both advantages of one-equation SGS model and a dynamic production term without test-filtering operation, which is particular suitable to relative coarse grid situations and high Reynolds number flows. The results of comparative investigations with and without generation of inflow turbulence show that: (1) proper simulation of an inflow turbulent field is essential in accurate evaluation of dynamic wind loads on a tall building and the prescribed inflow turbulence characteristics can be adequately imposed on the inflow boundary by the DSRFG method; (2) the DSRFG can generate a large number of random vortex-like patterns in oncoming flow, leading to good agreements of both mean and dynamic forces with wind tunnel test results; (3) The dynamic mechanism of the adopted SGS model behaves adequately in the present LES and its integration with the DSRFG technique can provide satisfactory predictions of the wind effects on the super-tall building.

• 한국항해항만학회지
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• 제31권6호
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• pp.479-484
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• 2007

항만 및 해안구조물의 설계시 사용되는 천해역에서의 파랑장 계산은 내륙 관측소의 바람자료를 이용하거나 심해파 추산모형에 의하여 추출된 심해파제원을 사용하는 것이 일반적이다. 그러나 전자의 경우는 관측소가 대부분 내륙에 위치하여 파랑발달을 모의하기 위한 정확한 바람자료를 얻기란 매우 어렵다. 또한, 후자의 경우는 아주 넓은 영역에서 큰 격자크기로 계산이 이루어지기 때문에 연안 및 천해역 지형을 상세히 재현하지 못하므로 임의의 정점에 대한 정확한 정보를 파악하기도 어렵다. 따라서, 본 연구에서는 우리나라 동남부 해역의 태풍 ‘매미’ 내습시의 파랑 관측자료를 사용하여 천해역에서의 파랑장 계산을 수행하였다. 또한, 계산된 파랑장의 정확도를 확인하기 위하여 울산해역 인근의 파고 및 파향 관측결과를 비교 검토하였다. 울산해역에 대한 파고분포 산출결과, 관측정점에서 파고는 ${\pm}1.3%$의 차이를 보여 기존의 방법 보다 높은 정확도를 보이는 것으로 나타났다.

• Structural Monitoring and Maintenance
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• 제1권1호
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• pp.47-67
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• 2014

This study has been motivated to examine the performance of a wireless sensor system under the typhoons as well as to analyze the effect of the typhoons on the bridge's vibration responses and the variation of cable forces. During the long-term field experiment on a real cable-stayed bridge in years 2011-2012, the bridge had experienced two consecutive typhoons, Bolaven and Tembin, and the wireless sensor system had recorded data of wind speeds and vibration responses from a few survived sensor nodes. In this paper, the wireless structural health monitoring of stay cables under the two consecutive typhoons is presented. Firstly, the wireless monitoring system for cable-stayed bridge is described. Multi-scale vibration sensor nodes are utilized to measure both acceleration and PZT dynamic strain from stay cables. Also, cable forces are estimated by a tension force monitoring software based on vibration properties. Secondly, the cable-stayed bridge with the wireless monitoring system is described and its wireless monitoring capacities for deck and cables are evaluated. Finally, the structural health monitoring of stay cables under the attack of the two typhoons is described. Wind-induced deck vibration, cable vibration and cable force variation are examined based on the field measurements in the cable-stayed bridge under the two consecutive typhoons.

• 한국방재안전학회논문집
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• 제16권4호
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• pp.19-31
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• 2023

미래 기후 시나리오에 따르면 우리나라 자연재해의 주요 요인인 태풍의 강도는 강해질 것으로 전망된다. 태풍 강도 증가는 내습 파고 상승으로 이어져 주거, 산업, 관광 등의 용도로 인구 및 건물 밀집도가 높은 연안 지역의 대규모 피해발생 가능성이 높은 상황이다. 따라서 본 연구에서는 동해 해양기상부이 관측자료를 분석하여 최대 유의파고가 나타난 태풍 마이삭(202009) 내습 기간에 대해 파랑추산 수치모형실험을 수행하였다. 파랑추산실험 경계조건은 JMA-MSM의 바람장과 SSP5-8.5 미래 기후 시나리오의 태풍 중심기압 감소율을 적용한 바람장을 사용하였다. 파랑추산실험 결과 SSP5-8.5 시나리오에서 속초항 방파제 전면에서의 파고는 4.06 m에서 4.68 m로 15.27% 증가하였다. 또한, 심해설계파 147-2 격자점 위치에서의 재현빈도는 최소 2배 이상 증가하는 것으로 산출되어, 현재 해안구조물 설계 시 관행적으로 적용하는 50년 재현빈도 심해설계파에 대한 제고가 필요하다.