• 한국방재학회 논문집
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• 제8권5호
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• pp.45-51
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• 2008

강풍과 강한 동반 강우로 인한 최근의 태풍 피해 증가로 인하여 태풍의 영향을 예측하고 분석하는 연구의 필요성이 증가하고 있다. 이에 따라 본 연구에서는 태풍에 동반되는 강우에 초점을 맞추어 태풍 동반 강우에 영향을 끼치는 두 가지의 요인을 선택한 후 태풍 이동 경로에 대한 기상관측지점의 상대각도를 이용하여 2가지의 태풍 동반 강우의 통계적 모형을 제안하였다. 또한 본 연구에서 제안한 통계적 모형의 유효성 증명 및 두 모형에의 적용에 대한 결과의 비교를 위하여 2007년에 우리나라에 영향을 끼친 태풍 나리에 의한 동반 강우의 통계적 예측을 수행하였으며, 그 결과 본 논문에서 제안하는 모형을 이용하여 어느 정도 태풍 동반 강우의 예측이 가능할 것으로 판단된다.

• 한국해양공학회지
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• 제18권2호
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• pp.25-32
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• 2004

We surveyed the coastal structure damage created by typhoon ‘Maemi’, which heavily struck the Korean peninsula on September 12, 2003. The survey revealed that high tides and strong winds induced by the typhoon were the main causes of the coastal damage, especially in the Busan areas. Though some experimental real-time coastal monitoring stations captured the typhoon movements at the critical time, more systematic and complete system should be implemented to save human lives and property from huge typhoon disasters.

• Wind and Structures
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• 제19권4호
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• pp.421-441
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• 2014

With the assistance of typhoon field data at aerial elevation level observed by meteorological satellites and wind velocity and direction records nearby the ground gathered in Guangzhou Weather Station between 1985 and 2001, some key wind field parameters under typhoon climate in Guangzhou region were calibrated based on Monte-Carlo stochastic algorithm and Meng's typhoon numerical model. By using Peak Over Threshold method (POT) and Generalized Pareto Distribution (GPD), Wind field characteristics during typhoons for various return periods in several typical engineering fields were predicted, showing that some distribution rules in relation to gradient height of atmosphere boundary layer, power-law component of wind profile, gust factor and extreme wind velocity at 1-3s time interval are obviously different from corresponding items in Chinese wind load Codes. In order to evaluate the influence of typhoon field parameters on long-span flexible bridges, 1:100 reduced-scale wind field of type B terrain was reillustrated under typhoon and normal conditions utilizing passive turbulence generators in TJ-3 wind tunnel, and wind-induced performance tests of aero-elastic model of long-span Guangzhou Xinguang arch bridge were carried out as well. Furthermore, aerodynamic admittance function about lattice cross section in mid-span arch lib under the condition of higher turbulence intensity of typhoon field was identified via using high-frequency force-measured balance. Based on identified aerodynamic admittance expressions, Wind-induced stochastic vibration of Xinguang arch bridge under typhoon and normal climates was calculated and compared, considering structural geometrical non-linearity, stochastic wind attack angle effects, etc. Thus, the aerodynamic response characteristics under typhoon and normal conditions can be illustrated and checked, which are of satisfactory response results for different oncoming wind velocities with resemblance to those wind tunnel testing data under the two types of climate modes.

• Structural Engineering and Mechanics
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• 제17권5호
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• pp.655-670
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• 2004

This paper aims to evaluate the effect of typhoons on fatigue damage accumulation in steel decks of long-span suspension bridges. The strain-time histories at critical locations of deck sections of long-span bridges during different typhoons passing the bridge area are investigated by using on-line strain data acquired from the structural health monitoring system installed on the bridge. The fatigue damage models based on Miner's Law and Continuum Damage Mechanics (CDM) are applied to calculate the increment of fatigue damage due to the action of a typhoon. Accumulated fatigue damage during the typhoon is also calculated and compared between Miner's Law and the CDM method. It is found that for the Tsing Ma Bridge case, the stress spectrum generated by a typhoon is significantly different than that generated by normal traffic and its histogram shapes can be described approximately as a Rayleigh distribution. The influence of typhoon loading on accumulative fatigue damage is more significant than that due to normal traffic loading. The increment of fatigue damage generated by hourly stress spectrum for the maximum typhoon loading may be much greater than those for normal traffic loading. It is, therefore, concluded that it is necessary to evaluate typhoon induced fatigue damage for the purpose of accurately evaluating accumulative fatigue damage for long-span bridges located within typhoon prone regions.

• 한국환경과학회지
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• 제21권2호
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• pp.263-266
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• 2012

To compare the effects of two external forcing on track of typhoon, TWRF(Typhoon WRF) based ensemble experiments are carried out in the case of Typhoon Morako which is the 8th typhoon at Northwest Pacific region in 2009. The two forcing are tropical SST and topography induced thermal and mechanical forcing, respectively. According to the result of numerical experiment for five-day forecast, the effect of mechanical forcing is about two times stronger than thermal forcing on the track error of the typhoon. More case study for other typhoon will be done as a next paper.

• Wind and Structures
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• 제20권2호
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• pp.293-314
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• 2015

In this paper, wireless monitoring of typhoon-induced variation of dynamic characteristics of a cable-stayed bridge is presented. Firstly, cable-stayed bridge with the wireless monitoring system is described. Wireless vibration sensor nodes are utilized to measure accelerations from bridge deck and stay cables. Also, modal analysis methods are selected to extract dynamic characteristics. Secondly, dynamic responses of the cable-stayed bridge under the attack of two typhoons are analyzed by estimating relationships between wind velocity and dynamic characteristics. Wind-induced variations of deck and cable vibration responses are examined based on the field measurements under the two consecutive typhoons, Bolaven and Tembin. Finally, time-varying analyses are performed to investigate non-stationary random properties of the dynamic responses under the typhoons.

• 대기
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• 제26권4호
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• pp.635-647
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• 2016

The effects of sea surface temperature (SST) gradient induced by the previous typhoon on the following typhoon motion over East Asia have been investigated using Weather Research and Forecasting (WRF) model for the previous Typhoon Bolaven (1215) and following Typhoon Tembin (1214). It was observed that Typhoon Bolaven remarkably reduced SST by about $7^{\circ}C$ at Yellow Sea buoy (YSbuoy). Using the WRF experiments for the imposed cold wake over West of Tembin (WT) and over East of Tembin (ET), this study demonstrates that the effects of eastward SST gradient including cold wake over WT is much significant rather than that over ET in relation to unexpected Tembin's eastward deflection. This difference between two experiments is attributed to the fact that cold wake over WT increases the magnitude of SST gradient under the eastward SST gradient around East Asia and the resultant asymmetric flow deflects Typhoon Tembin eastward, which is mainly due to the different atmospheric response to the SST forcing between ET and WT. Therefore, it implies that the enhanced eastward SST gradient over East Asia results in larger typhoon deflection toward the region of warmer SST according to the location of the cold wake effect. This result can contribute to the improvement of track prediction for typhoons influencing the Korean Peninsula

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.85-89
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• 2007

Data of the typhoon affecting Korean peninsula from 1951 to 2005 are obtained from the RSMC best track and six climatological characteristics of the typhoons are examined. Local wind speeds are obtained by the physical model for wind fields. Typhoons are generated by the Monte Carlo simulation and their wind speeds are distributed using Weibull CDF. Simulated typhoon wind speeds are used to obtain different wind speeds corresponding their mean recurrence intervals.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.93-96
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• 2008

Considering the loss due to typhoon is increasing, estimation and analysis of a typhoon's influence has become more important. On this basis, the statistical models were presented in this paper by two principal elements. Comparisons between the estimated rainfall rate of these models and the observed value in the duration of Typhoon NARI(2007) were analyzed to confirm the availability of these models.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.111-116
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• 2004

We surveyed the coastal structure damages due to the typhoon 'Mae-mi' which heavily struck Korean peninsula in September 12, 2003. The survey revealed the typhoon induced high tides and strong winds were the main causes especially in Busan areas. Though some experimental real time coastal monitoring stations captured the typhoon movements at the critical time, more systematic and complete systems should be implemented to save human lives and properties from huge typhoon disasters.