• Structural Engineering and Mechanics
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• 제85권1호
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• pp.81-88
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• 2023

This paper begins by analyzing cable vibrations due to external excitations and their effects on the overall dynamic behavior of cable-stayed bridges. It is concluded that if the natural frequency of a cable approaches any natural frequency of the bridge, the cable loses its rigidity and functionality. The results of this analysis explain the phenomenon that occurred on the Dubrovnik Bridge in Croatia during a storm and measures for its retrofit. A field test was conducted before the bridge was opened to traffic. It was concluded: "The Bridge excited unpleasant transverse superstructure vibration with the frequency of approximately 0.470 Hz. Hence, it seems possible that a pair of stays vibrating in phase may excite deck vibrations". Soon after this Bridge opened, a storm dumped heavy damp snow in the area, causing the six longest cable stay pairs of the main span to undergo large-amplitude vibrations, and the superstructure underwent considerable displacements in combined torsion-sway and bending modes. This necessitated rehabilitation measures for the Bridge including devices to suppress the large-amplitude vibrations of cables. The rehabilitation and monitoring of the Bridge are also presented here.

• Current Research on Agriculture and Life Sciences
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• 제31권4호
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• pp.280-285
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• 2013

국내에 설치되어 있는 원예시설 중 가장 많은 면적을 차지하고 있는 단동비닐하우스의 기상재해로 인한 피해를 경감시킬 수 있는 모델 개발에 필요한 기초자료를 제공하고자 재배작물별로 대표적인 온실규격를 선정하여 안전풍속과 적설심을 구한 후 재현기간 8년에 해당하는 지역의 설계풍속 및 적설심과 비교하여 온실의 구조 안전성을 분석한 결과를 요약하면 다음과 같다. 1. 재배작물별 대표온실에 단위풍하중을 적용한 결과, 최대 단면력은 과채류, 근채류, 엽채류 온실 순으로 크게 나타났으며 재배작물별 서까래 간격을 고려한 안전풍속은 엽채류 온실이 17.7 m/s, 과채류 온실이 20.2 m/s, 근채류 온실이 22.3 m/s로 나타나 지역별 8년 빈도의 설계풍하중과 비교하였을 때 홍천, 이천, 성주지역을 제외하고는 대부분의 지역에 있어서 불안전한 것으로 나타났다. 2. 재배작물별 대표온실에 단위 적설하중을 적용한 결과, 근채류 온실의 최대 단면력이 가장 크게 나타났으나 재배작물별 서까래 간격을 고려한 안전적설심은 엽채류 온실이 8.8 cm, 과채류 온실이 9.4 cm, 근채류 온실이 11.8 cm인 것으로 나타났다. 이러한 결과를 지역별 8년 빈도의 적설하중과 비교하였을 때 경남지역 일부를 제외하고는 대부분의 지역에 있어서 불안전한 것으로 분석되었다. 3. 재배작물별 대표 온실의 안전풍속과 적설심에 대하여 구조물에 발생하는 최대 인발력은 12.7~15.1 kgf/개소, 최대 연직하중은 20.6~21.7 kgf/개소로 나타나 기초는 안전한 것으로 분석되었으나 안전풍속과 안전적설심이 매우 작기 때문에 폭설이나 강풍에 대비한 보강이 필요한 것으로 나타났다. 4. 재배작물별 대표온실의 안전풍속과 적설심을 증가시키기 위해서는 서까래 간격을 감소시키거나 부재의 단면 치수를 증가시키는 등의 보강대책이 필요한 것으로 나타났다.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2011년도 춘계학술대회
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• pp.67-77
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• 2011

The railroad system must ensure not only the safety of facilities but also the prevention of natural and environmental disasters. The infrastructure must be strengthened in order to prevent rail damage by natural disasters and other causes. Thus, it would be able to prevent damage due to such natural factors like heavy rain and snow fall, wind, and catastrophic earthquakes. It seems that it would be the best way to install safety facilities throughout the entire length of a route, but one would not be able to provide for the costs involved in this approach. Therefore, these facilities must be installed at selected locations that is the most vulnerable to disasters. In this paper we propose the examples of both foreign and domestic methods in order to prevent from damages caused by the above-mentioned natural disasters and others.

• Geomechanics and Engineering
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• 제29권3호
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• pp.349-357
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• 2022

Abnormal climate events are occurring frequently around the world. In particular, cold waves and heavy snow lead to damage and deterioration of facilities, which can cause loss of life or property damage, such as shortening the lifespan of facilities. Therefore, it is very important to prepare an appropriate maintenance system and to establish a strategy to cope with abnormal weather conditions. In this study, laboratory freezing experiments were performed to analyze the freeze-thaw characteristics affecting the tunnel concrete lining, and heat flow analysis was carried out based on the test results. Based on these experimental and theoretical analysis results, quantitative freeze-thaw evaluation criteria for tunnel concrete linings were proposed.

• 산업경영시스템학회지
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• 제46권3호
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• pp.7-14
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• 2023

Recently, the importance of impact-based forecasting has increased along with the socio-economic impact of severe weather have emerged. As news articles contain unconstructed information closely related to the people's life, this study developed and evaluated a binary classification algorithm about snowfall damage information by using media articles text mining. We collected news articles during 2009 to 2021 which containing 'heavy snow' in its body context and labelled whether each article correspond to specific damage fields such as car accident. To develop a classifier, we proposed a probability-based classifier based on the ratio of the two conditional probabilities, which is defined as I/O Ratio in this study. During the construction process, we also adopted the n-gram approach to consider contextual meaning of each keyword. The accuracy of the classifier was 75%, supporting the possibility of application of news big data to the impact-based forecasting. We expect the performance of the classifier will be improve in the further research as the various training data is accumulated. The result of this study can be readily expanded by applying the same methodology to other disasters in the future. Furthermore, the result of this study can reduce social and economic damage of high impact weather by supporting the establishment of an integrated meteorological decision support system.

• 한국관개배수논문집
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• 제18권2호
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• pp.111-121
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• 2011

This study is to estimate the possible damage area of greenhouse by heavy snowfall event using terra MODIS snow cover area (SCA) and the ground measured snowfall data (GMSD). For the 4 heavy snowfall events of January 2001, March 2004, December 2005 and January 2010, the areas exceeding the design criteria of snowfall depth for greenhouse breaking were extracted by coupling the MODIS SCA and GMSD. The main damaged regions were estimated as Gangwon province in 2001, Chungbuk and part of Gyeongbuk province in 2004, Jeonbuk and Jeonnam province in 2005, and Gangwon and part of Gyeonggi province in 2010 respectively. Comparing with the investigated number of greenhouse damaged data, the estimated areas reflected the statistical data except 2001. The 2001 greenhouse damages were caused by the high wind speed (35.7m/sec) together with snowfall. The results of this study can be improved if the design criteria of wind speed is added.

• 한국디지털건축인테리어학회논문집
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• 제12권4호
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• pp.67-75
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• 2012

The damage of greenhouse has been increasing due to frequent collapse of frame in greenhouse caused by the heavy snow and strong wind. But, greenhouses are constructed by steel tube members of pipe style and pin connection of them, so these greenhouses are very weak. Therefore, this study was carried out to find the type of member section and structural frame system in stress tolerant greenhouses. The modeling types for analysis were designed in accordance with structural frame configuration and member section in greenhouse. These types of models, which are existing type, diagrid type, symmetric and asymmetric section type of frame member in greenhouse were classified. Displacement analysis varying the vertical and horizontal loads for a series of models was carried out. As a result of this paper, it was verified that the structural frame configuration of diagrid type and asymmetric type of member section is better than existing type in the frame of greenhouses against snow loads and wind loads.

• 대한토목학회논문집
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• 제40권6호
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• pp.563-569
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• 2020

기상현상 발생에 대한 기존 기상예보 방식에서 벗어나 기상재해가 사회와 인간생활에 끼치는 영향을 제공함으로써 사전에 영향범위에 대한 피해예방 및 행동예방을 취할 수 있는 영향예보를 제공하는 것이 필요하다. 이를 위해 미국, 영국, 프랑스 등 세계 각국에서는 호우, 폭설, 한파 등의 영향예보를 시행하고 있으며, 보다 효율적인 예보방안에 대해 고민하고 있다. 본 연구에서는 여러 기상현상 중 호우에 대한 영향예보를 국내의 실정에 맞도록 개선하고, 적용하기 위해 33개의 호우영향인자(Impact Library)를 격자단위(1 km)로 구축하고, 표준정규분포법을 이용하여 4개의 위험등급(Minimal, minor, significant, severe)의 기준을 산정하였다. 산정된 기준은 호우영향 대상체인 사람, 시설, 농업, 교통을 중심으로 한 6개의 카테고리(Residential, commercial, utility, community, agriculture, transport)에 대한 호우위험영향(Heavy rain risk impact)를 산정하기 위한 지표로 활용된다.

• 한국안전학회지
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• 제31권2호
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• pp.119-126
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• 2016

Across the world, the industrialization has increased the frequency of climate anomaly. The size of damage due to recent natural disasters is growing large and fast, and the human damage and economic loss due to disasters are consistently increasing. Urbanization has a structure vulnerable to natural disasters. Therefore, in order to reduce damage from natural disasters, both hardware and software approaches should be utilized. Currently, however, the development of a statistical access process for 'analysis of disaster occurrence factor' and 'prediction of damage costs' for disaster prevention and overall disaster management is inadequate. In case of local governments, overall disaster management system is not established, or even if it is established, unscientific classification system and management lead to low utility of natural statistics of disaster year book. Therefore, in order to minimize disaster damage and for rational disaster management, the disaster damage survey process should be improved. This study selected gale as the focused analysis target among natural disasters recorded in disaster year book such as storm, torrential rain, gale, high seas, and heavy snow, and analyzed disaster survey process. Based on disaster year book, the gale damage size was analyzed and the issues occurring from the correlation of gale and damage amount were examined, so as to suggest an improvement plan for reliable natural disaster information collection and systematic natural disaster damage survey.

• 대한건축학회논문집:구조계
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• 제33권12호
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• pp.3-10
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• 2017

Climate change not only has various impacts such as human shoes, economics, the environment, industry, etc. but the damage caused by this is also increasing, it is expected that severe damage will not occur without efforts to respond to climate change ing. Therefore, as the impact of climate change like the extreme weather phenomenon is dailyized and its strength tends to become stronger, as much as the mitigation measures of climate change, as a comparative effort to reduce the negative impact of climate change, adaptation to climate change is necessary. Especially when the damage caused by climate change (intense heat, torrential rain, cold wave and heavy snow etc.) as an institution responsible for the provision of public services such as public institutions, the socio-economic spread to the nation and the people The effect is very large. We confirmed the level of response to climate change for the entire public institution, and selected climate change risk which is relatively important for specific facilities and business establishments of public institutions, climate change adaptation measures We will try to utilize it as basic material of establishment.