• 한국공간구조학회논문집
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• 제15권3호
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• pp.43-49
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• 2015

A single-layerd steel lattice roof, which has 50m span, was constructed. In order to figure out the realistic buckling load level, the structural analysis of this roof structure was performed especially by local snow load. Due to the characteristics of application of snow load, the load combinations of snow should be considered not only global area but also local part so that the critical buckling load could be observed as easy as possible. Geometrical imperfection was simulated to consider inaccurate shape of structure. And then nonlinear analysis were performed. Finally, this paper could investigate that the local snow load with geometrical imperfection decreased the level of buckling load significantly.

• 한국공간구조학회논문집
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• 제23권1호
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• pp.69-76
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• 2023

A timber lattice roof, which has around 30m span, was constructed. In order to figure out the realistic buckling load level, the structural analysis of this roof structure was performed especially by stiffness of connection with various asymmetric snow load. Due to the characteristics of application of snow load, the load combinations of snow should be considered not only global area but also local part so that the critical buckling load could be observed as easy as possible. Geometrical imperfection was simulated to consider inaccurate shape of structure. And then nonlinear analysis were performed. Finally, this paper could investigate that the asymmetric snow load with the lower level stiffness of connection decreased the level of buckling load significantly.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.156-163
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• 2005

This study was attempted to provide some fundamental data for safety structrural design of biological production facility. Wind load and snow load, acting on agricultural structures is working more sensitive than any other load. Therefore, wind speed and snow depth according to return periods for design load estimation were calculated by frequency analysis using the weather data(maximum instantaneous wind speed, maximum wind speed, maximum depth of snow cover and fall) of 68 regions in Korea. Equations for estimating maximum instantaneous wind speed with maximum wind speed were developed for all, inland and seaside regions. The results were about the same as the current eqution in general. Design wind speed and snow depth according to return periods were calculated and Local design wind load and snow load depending on return periods were presented together with iso-wind speed and iso-snow depth maps. The calculated design snow depth by maximum depth of snow cover were higher than design snow depth by maximum depth of snow fall. Considering wind speed and snow depth, protected cultivation is very difficult in Ullungdo, Gangwon seaside and contiguity inland regions, and strong structural design is needed in the west-south seaside against wind speed, and structure design of biological production facility in these regions need special consideration.

• 한국농촌건축학회논문집
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• 제20권1호
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• pp.19-26
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• 2018

The roof improvement project is being carried out under the government's leadership for the sake of national welfare. The project is to replace the asbestos slate roof with a metallic one. In this study, the structural safety of the improved roof was examined and the project guidelines were reviewed. The causes of the roof damage were investigated and the structural analysis was performed for the roof frame subject to wind and snow loads. Metallic roof assemblies have higher strength and load resistance capability than usual slate ones, so the structural safety is governed by the frame. The stresses of the roof frame elements caused by the wind and snow loads were analyzed according to roof frame with various spacings between the rafters and the purlins. Wind load analysis was performed by 24, 28, and 38 m/sec of the basic wind speed. Snow load analysis was carried out by 0.5, 1.0 and $2.0kN/m^2$ of the ground snow load. As the analysis result, the current spacing and the size of the lumber did not satisfy the Korean building code specification. To secure the safety of the roof improvement project, the spacing of the roof frame elements and the size of the lumber should be determined based on the analysis results by structural engineers.

• 대한토목학회논문집
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• 제34권5호
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• pp.1421-1433
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• 2014

본 연구에서는 적설심 빈도분석을 수행하기 위해 우리나라에 가장 적합한 확률분포형과 모수추정방법을 선정하였다. 최적확률분포형으로는 Generalized Extreme Value (GEV), 모수추정방법으로는 확률가중모멘트법이 선정되었다. 선정된 확률분포형과 모수추정방법을 적용하여 우리나라 69개 기상관측소별 적설심 빈도분석을 수행하였다. 빈도분석을 통해 관측소별 빈도별 적설심을 산정하였고 적설심과 눈의 단위중량을 이용하여 적설하중을 산정하였다. 산정된 적설하중 중 100년 빈도 적설하중을 이용하여 ArcGIS 크리깅(Kriging) 기법을 통해 우리나라 설계적설하중 지도를 작성하였다. 또한, 본 연구를 통해 산정된 적설하중과 건축구조기준 및 해설(2009)에서 제시하고 있는 설계적설하중을 비교하여 설계적설하중 기준의 적정성을 평가하였다. 평가결과, 대부분의 지역에서 현재 지상적설하중 기준의 상향조정이 요구되었으며 본 연구를 통해 도출된 결과를 반영하여 보다 합리적인 지역별 설계적설하중을 제안하였다. 본 연구를 통해 제안된 지역별 설계적설하중은 폭설에 대비한 우리나라 전역의 구조물 설계에 활용될 수 있을 것으로 기대된다.

• 한국농공학회논문집
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• 제63권2호
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• pp.75-84
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• 2021

As the weather changes become frequent, weather disasters are increasing, causing more damage to plastic greenhouses. Among the damage caused by various disasters, damage by snow to the greenhouse takes a relatively long time, so if an alarm system is properly prepared, the damage can be reduced. Existing greenhouse design standards and snow warning systems are based on snow depth. However, even in the same depth, the load on the greenhouse varies depending on meteorological characteristics and snow density. Therefore, this study aims to secure the structural safety of greenhouses by developing sensors that can directly measure snow loads, and analysing the warning criteria for load using a stochastic model. Markov chain was applied to estimate the failure probability of various types of greenhouses in various regions, which let users actively cope with heavy snowfall by selecting an appropriate time to respond. Although it was hard to predict the precise snow depth or amounts, it could successfully assess the risk of structures by directly detecting the snow load using the developed sensor.

• 한국환경과학회지
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• 제31권10호
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• pp.815-824
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• 2022

It is necessary to understand the amount of snowfall and area of snow cover of Mt. Halla to ensure the safety of mountaineers and to protect the ecosystem of Mt. Halla against climate change. However, there are not enough related studies and observation posts for monitoring snow load. Therefore, to supplement the insufficient data, this study proposes an analysis of snow load and snow cover using normalized-difference snow index. Using the images obtained from the Sentinel2 satellite, the normalized-difference snow index image of Mt. Halla could be acquired. This was examined together with the meteorological data obtained from the existing observatory to analyze the change in snow cover for the years 2020 and 2021. The normalized-difference snow index images showed a smaller snow pixel number in 2021 than that in 2020. This study concluded that 2021 may have been warmer than 2020. In the future, it will be necessary to continuously monitor the amount of snow and the snow-covered area of Mt. Halla using the normalized-difference snow index image analysis method.

• 한국농공학회논문집
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• 제64권4호
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• pp.45-53
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• 2022

In this study, the loading test and structural analysis were performed on the snow load and the results were compared. The load plates were loaded on the roof surface of the model, and structural analysis was performed under the same conditions. The result of loading test, the maximum displacement was observed in the center of the top, and the maximum stress was observed near the bottom point. Displacement and stress were found to have a high linear relationship with the load. Comparing the structural analysis results with the loading test results, the maximum displacement difference is 4.5% and the maximum stress difference is 10.2%. It is expected that closer results can be derived if the boundary conditions for the longitudinal direction of the model are clarified during experiments and analysis.

• 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.

• 한국산학기술학회논문지
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• 제16권3호
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• pp.2242-2248
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• 2015

본 연구는 폭설로 인하여 비닐하우스가 붕괴되는 사고가 잇따르는 것에 대비하여 효율적인 비닐하우스 골조의 개선방안을 찾고자 진행되었다. 2013년 겨울, 비닐하우스 피해가 가장 컸던 곳은 경북과 강원도로, 이 지역에서 가장 많이 사용되고 있는 비닐하우스 유형(07-단동 3형, 07-단동 18형)에 대하여 최대 적설량 대비 30%까지 하중을 증가시켜 MIDAS GEN 프로그램을 사용하여 구조적 안전성을 검토하였다. 해석의 결과, 경주의 비닐하우스는 적설하중의 중가에 대해 안전하였으나 속초의 경우는 위험요인이 발생하였으며, 강릉의 비닐하우스는 기존 적설하중에서도 붕괴 가능성이 있는 것으로 나타났다. 폭설에 대비, 비닐하우스 구조단면의 성능을 개선하기 위하여 서까래를 이루는 원형파이프 단면의 성능을 개선하는 동시에 서까래의 간격을 증가시켜 적정 비닐하우스 구조를 검토한 결과, 서까래의 관경과 간격을 증가시키는 방안이 서까래의 두께와 간격을 증가시키는 방안보다 구조적으로 효율적인 것으로 해석되었다. 향후 폭설에 대비하여 비닐하우스의 서까래 관경을 증가시킨 적정 규격의 제안이 필요할 것으로 판단된다.