• Journal of The Korean Society of Agricultural Engineers
• /
• v.57 no.5
• /
• pp.13-17
• /
• 2015

There are many vinyl houses in rural areas. These vinyl houses have occasionally been collapsed due to heavy snow load in winter. If these vinyl houses are collapsed, many farmers get a lot of economical damages. So it is very important to built safe vinyl house that is able to withstand the applied heavy snow load. In this study, compressive buckling and flexural tests were performed to investigate the strength increase of circular mortar filled pipes. The results showed that buckling load and flexural moment of mortar filled pipes were increased 42 % ~ 82 %, 40 % ~ 44 % respectively more than only pipe without mortar. It is recommended that mortar filled pipes as main members of vinyl house have to be used to prevent collapsing due to the severe snow load.

• Journal of Korean Association for Spatial Structures
• /
• v.13 no.4
• /
• pp.83-90
• /
• 2013

PTEF membranes are used for roofing materials of membrane structures. PTEF is the abbreviation of Poly-tetra Fluotide-ethylene. These materials are consisted of fiberglass weave and polyetrfluoroethylene coating. Also, PTEF membranes have some problems of structural capacity by wind or snow load, etc. In this study, sensor housings using lead switches are bonding in PTFE membranes, Monitoring to changes tension and tear damages are studied using radio frequency. If tension is received on edged membranes, bonded lead switches of sensor housings will be destroyed by changes tension, and these become to send signals of damages at the connected radio frequency system with increased tension. Study of these functional membrane materials will be contributed to prevent water leakage and long-term maintenance of membrane structures.

• Journal of Wetlands Research
• /
• v.25 no.4
• /
• pp.345-352
• /
• 2023

Recently, the risk of snow disasters has been increasing South Korea. The damages of heavy snow were categorized into direct and indirect. Direct damage is usually the collapse of buildings as houses, greenhouse or barns. Indirect damage is various, for example, traffic congestion, traffic acident, drop damage, and so on. In South Korea, direct damage is severe in rural area, mosty collapse of greenhouse or barns. However, indirect damage such as traffic accident is mostly occurred in urban area. Therefore, the regional characteristics should be considered when vulnerability is evaluated. Therefore, in this study, the PSR and DPSIR method were applied by regional scale in South Korea. The PSR evaluation method is divided into pressure, state, and reaction index. however, the DPSIR evaluation method is divided into Driving force, Pressure, State, Impact, and Response index. the DPSIR evaluation method is divided into Driving force, Pressure, State, Impact, and Response index. Data corresponding to each indicator were collected, and the weight was calculated using the entropy method to calculate the snowfall vulnerability index by regional scale in South Korea. Calculated heavy snow damage vulnerabilities from the two methods were compared. The calculated vulnerabilities were validated using the recent snow damage in South Korea from 2018 to 2022. Snow vulnerability index calculated using the DPSIR method showed more reliable results. The results of this study could be utilized as an information to prepare the mitigation of heavy snow damage and to establish an efficient snow removal response system.

• Journal of Korea Water Resources Association
• /
• v.55 no.12
• /
• pp.1125-1135
• /
• 2022

Damages by heavy snow does not occur very often, but when it does, it causes damage to a wide area. To mitigate snow damage, it is necessary to know, in advance, the depth of snow that causes damage in each region. However, snow depths are measured at observatory locations, and it is difficult to understand the spatial distribution of snow depth that causes damage in a region. To understand the spatial distribution of snow depth, the point measurements are interpolated. However, estimating spatial distribution of snow depth is not easy when the number of measured snow depth is small and topographical characteristics such as altitude are not similar. To overcome this limit, satellite images such as Synthetic Aperture Radar (SAR) can be analyzed using Differential Interferometric SAR (DInSAR) method. DInSAR uses two different SAR images measured at two different times, and is generally used to track minor changes in topography. In this study, the spatial distribution of snow depth was estimated by DInSAR analysis using dual polarimetric IW mode C-band SAR data of Sentinel-1B satellite operated by the European Space Agency (ESA). In addition, snow depth was estimated using geostationary satellite Chollian-2 (GK-2A) to compare with the snow depth from DInSAR method. As a result, the accuracy of snow cover estimation in terms with grids was about 0.92% for DInSAR and about 0.71% for GK-2A, indicating high applicability of DInSAR method. Although there were cases of overestimation of the snow depth, sufficient information was provided for estimating the spatial distribution of the snow depth. And this will be helpful in understanding regional damage-causing snow depth.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.3
• /
• pp.1077-1086
• /
• 2013

Recent huge losses of both life and property have occurred by unexpected natural disasters. We studied snow damages, an important natural disaster issue because it happens more frequently in recent years. This study tries to select vulnerable areas of snowfall in advance and then establish climate change adaptation policy for minimizing unexpected snowfall damage. Busan, where is our study area, has hilly in downtown areas so that topography characteristics of the roads such as slope, elevation and aspect are vulnerable to snowfall. The sudden snowfall in Busan causes traffic jam and causes some schools in hilly to close some schools. At this moment, the adaptation policy has to be established for infrastructure (such as roads) in advance, because prediction of anomaly climate due to global warming is so difficult beside the damage of natural disaster is huge. Therefore, the purpose of this study is contribute to selecting and assessing vulnerable zones of snow damage focusing topography characteristics of the roads and then evaluating the degree of risk of vulnerable zones.

• Korean journal of applied entomology
• /
• v.16 no.4 s.33
• /
• pp.245-247
• /
• 1977

Penicillium digitatum SACCARD, P. italicum WEHMER, Botrytis cinerae PERSOON and Sclerotinia sclerotiorum MASSE. were the main storage diseases on the cold injured mandarin at Jeju in 1975. The losses observed through the materials used were $18.3\%$ which consists of $8.1\%$ by diseases and $10.2\%$ by water rot as the result of cold and snow damages at harvest stage in Jeju. The total amount of damages estimated at shipping stage were 915M/T in value of 135 million Won from the rot waste of 675M/T by the end of 1975. Since cold injury is known as the main factor of the fruit rot, shipping and storage process as well as disease control measures are discussed.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.1
• /
• pp.19-28
• /
• 2017

In this paper, detailed safety inspection reports on the 915 expressway bridges which had been published from 1996 to 2010 are collected and condition of these bridges are analyzed. Damages are categorized into 'damage by defect', 'damage by physical force', and 'damage by deterioration' and the concept of damage possession rate is introduced to investigate the occurrence time and the characteristics of damages. Based on the top 10 damage patterns of expressway bridges and the deterioration characteristics of heavy snow and freezing cold area, reasonable improvement direction of inspection activity is suggested. From this study, it is known that improvement of inspection regularization during construction or at completion stage of bridges is needed. Since the deterioration progress of the heavy snow and freezing cold area is faster than that of general area, environmental characteristics should be considered in inspection activity. The results of present study can be widely used for improvement of inspection activity of expressway bridges.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2006.04a
• /
• pp.313-318
• /
• 2006

The main cause of natural disaster in Korea is meteorological phenomenon, such as typhoon, heavy rain, storm, rainstorm, heavy snow, hailstorm, overflowing of sea and so on(including thunderstroke, blast, snow damage, freezing and earthquake), and among those disasters, heavy rain takes place most often, and it occupies 80% of total disaster Especially, disaster related to slope collapse (landslide, collapse of retaining wall, burying ect.) takes place every year due to meteorological cause such as localized heavy rain, which is getting stronger. (National Institute for Prevention Disaster, 2002, Meteorological Administration) Accordingly, it is necessary to analyze the features of slope collapse related to natural disaster in Korea, and also to make up counterplan to prevent disaster. This paper will try to analyze potential areas which are susceptible to landslide regarding factors inducing landslide and heavy rain, and to evaluate the potentiality of landslide regarding local particularity of rainfall, furthermore to provide essential information for development of community such as preventing damages from landslide, construction Industry, and effective use of land.

• Journal of the Korean Society of Safety
• /
• v.34 no.2
• /
• pp.34-39
• /
• 2019

Vinyl house consists of main rafter, lateral member, clamps and polyethylene film. Many vinyl houses are used in the countryside to grow vegetables. These vinyl houses have occasionally been collapsed due to heavy snowfall in winter. Many farmers get a lot of economical damages, if vinyl houses are collapsed. So it is most important to built a safe vinyl house that can withstand heavy snowfall. In this study, a structural analysis was performed on three types of vinyl houses(07-single-01, 10-single-04, 12-single-01). In addition, the structural analysis of the three types of vinyl houses provided axial forces, flexural moment, and combined stress. For these three types of vinyl houses, structural safety was reviewed by obtaining the combined stress ratio by the strength design method. This structural review showed that the specifications for the vinyl house proposed in the design are not safe. Especially, the result of increasing the design snow load by 15 percent and 30 percent showed that the vinyl house structure constructed as a standard for vinyl house was a more dangerous structure. Therefore, it is necessary to revise regulations such as increasing the thickness of rafters or widening the gap in order to make vinyl houses structurally safe for heavy snowfall in the future, and to devise diverse methods to make vinyl houses that are structurally safe.

• Journal of the Korean GEO-environmental Society
• /
• v.19 no.12
• /
• pp.59-64
• /
• 2018

The damages to the reinforced earth retaining wall are divided into the front wall, foundation, drainage and upper slope. Damage of reinforced earth retaining wall is mainly caused by damage caused by drainage problem in the field. Recently, damage caused by snow removal materials have been occurred. Recently, the amount of snow removal materials used in winter is increasing due to abnormal weather. This chlorides degrades the concrete structure, where the reinforced earth retaining wall was no exception. There has recently been a case in which the front wall of the reinforced earth retaining wall deteriorates due to the chlorides introduced into the back filling portion through the drainage passage. Therefore, in this study, the cause of damages of reinforced earth retaining wall constructed in bridge abutment was analyzed, and an analytical study was conducted on the countermeasure. As a result, it was found that chlorides, which was introduced through the drainage system in the expansion joint of the bridge shift part or the upper structure, is infiltrated into the back part of the reinforced earth retaining wall and damaged. Therefore, it is suggested to improve the drainage system and restored the stiffness of the front wall.