• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.82-82
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• 2011

현재 도로 포장 설계시 동결심도의 결정은 30년간 관측한 기상자료 분석을 통해서 얻은 동결지수를 근거로 하여 동결심도를 산정한다. 그러나 기후 온난화 현상 등 변화된 기상조건과 대기온도를 근거로 작성된 동결지수와 대기온도에 따른 실제 포장 내부의 온도 변화를 반영하지 못하고 있다. 따라서, 본 연구에서는 설계시 산정된 동결심도와 실제 현장의 동결심도의 차이를 확인하기 위하여 한반도 북부지역을 동결지수에 따라 동결지수 $550{\sim}650^{\circ}C{\cdot}$일, $450{\sim}550^{\circ}C{\cdot}$일, $350{\sim}450^{\circ}C{\cdot}$일, $350^{\circ}C{\cdot}$일 이하로 구분하여 15개 지역을 선정하였고, 각 지역별로 절토부, 절성경계부, 저성토부(2m 이하 성토부) 구간으로 45단면을 구분하여 현장계측시스템을 구축하였다. 그리고 현장계측시스템으로부터 얻어진 대기온도와 포장층별 온도를 이용하여 현장 동결심도를 산정하고 동결심도 산정식의 동결심도와 비교하였다. 또한, 현장 동결심도를 이용하여 동결심도선도를 작성하였다.

• International Journal of Highway Engineering
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• v.7 no.2 s.24
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• pp.87-95
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• 2005

To prevent the lowering of structural capability due to freezing and thawing in cold winter, numerous researches on frost heaving have been performed. As the result, the freezing index contour map of the Korea peninsula has been made for the design of the anti-freezing layer of pavements. However, the validity of the anti-freezing layer needs to be evaluated because systematic investigations on the variation of freezing depth with the thickness and material types of pavement layers and the configuration of the ground have been rarely performed. The freezing index of the Korea Highway Corporation test road site was calculated and the freezing depths of the concrete and asphalt pavements of the test road were investigated using the ambient and pavement temperature and water content. In addition, the investigated freezing depths were compared to the values estimated by existing freezing depth models. This is the preliminary study on the freezing-related data measured at the test road. The results with higher reliability will be produced by the long-term accumulation of the data and the analysis on it.

• Journal of Korea Soil Environment Society
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• v.1 no.1
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• pp.103-109
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• 1996

The cover liners at municipal and hazardous waste landfill is not emphasized as much as the bottom liners. However, one of the most effective reason of landfill destroy is the cover liner failure. The cover system at municipal and hazardous waste landfill, 1 perform the following functions, at minimum: promote surface runoff, impede infiltration, protect settlement in the landfill, and provide a buffer from surface exposure of the waste. This research was to expand the existing knowledge base of landfill cover liner behavior during period of freeze/thaw Also, the great Lysimeter was built in the laboratory to provide as much as same condition with the field and three designs were simulated by actual cover materials. The result of simulation indicated the clay was effected by freezing/thawing. The degradation of cover liners in the frost penetration affects the physical, engineering properties of clay. these factors may consider to design and construct of the landfill. This paper provides the description of testing cover liners, experimental results and a discussion of the results of the simulation.

• International Journal of Highway Engineering
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• v.13 no.1
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• pp.21-32
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• 2011

The frost penetration depth of pavement is usually estimated from the freezing index that made temperature data analysis of 30 years and decided the thickness of anti-frost layer. The field monitoring region in study was divided into five regions by freezing index 550~650$^{\circ}C{\cdot}$day, 450~550$^{\circ}C{\cdot}$day and 350~450$^{\circ}C{\cdot}$day. Each region has three-section of road pavement such as cutting area, boundary area of cutting and banking, and lower area of banking. The field monitoring system was established both in the section of anti-frost layer and in the section without anti-frost layer. The data analysis was conducted for determination of frost penetration depth within the paved road by the field monitoring system. The result showed that The temperature of subgrade without anti-frost layer shows below zero in centigrade for the region of freezing index 550~650$^{\circ}C{\cdot}$day, up and down around zero degree in subgrade for the region of freezing index 450~550$^{\circ}C{\cdot}$day, and there is no place existed below zero degree in subgrade for the region of freezing index below 450$^{\circ}C{\cdot}$day. With comparison of field frost penetration depth for the cross-sections of pavement, the cutting area shows the greatest frost penetration depth, and less influence of frost penetration depth for the boundary area of cutting and banking, and the least influenced for the lower area of banking.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.90.1-90.1
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• 2010

우리나라는 계절적 특성으로 인하여 겨울에서 봄에 이르기까지 도로포장의 동결 융해가 반복되어 도로 파손을 유발 시키고 있다. 동결 융해로 인한 피해를 줄이기 위하여 도로포장 설계시 동상방지층을 별도로 설치를 하고 있으나 실효성 검증 없이 무분별하게 적용되고 있어 국가적으로 예산을 낭비하고 있다. 본 연구에서는 효과적인 동상방지층의 설계를 목적으로 계측된 온도 및 함수비 데이터를 효율적으로 관리하고 모니터링하는 기반을 마련하고자 한다.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.506-514
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• 2016

Experimental ballast track and concrete track were installed on the railway site and the frost penetration depth and the frost heave amount in the winter were measured. As a result, when the freezing index was the same, the frost penetration depth of concrete track was deeper than that of ballast track. Furthermore, when an XPS and polyethylene aggregate layer was installed below the ballast track, the frost penetration depth of the ballast track decreased significantly; in the case of the concrete track, the frost penetration depth decreased when the thickness of the subbase increased. Meanwhile, the frost heave amount also decreased when an XPS and polyethylene aggregate layer was installed below the ballast track ; in the case of the concrete track, the frost heave amount decreased when the thickness of the subbase increased.

• Journal of the Korean GEO-environmental Society
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• v.10 no.4
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• pp.15-24
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• 2009

Korea is known to have seasonal frost during winter and the effect of low temperatures and water may cause a weakening of pavements. For that reason, frost protection layers have been constructed in pavements to avoid damage caused by frost action. The practies established in USA and Japan have been adopted as anti-frost design methods in Korea. However, the characteristics of Korean soils are different. Additionally, there is no formulation of a reasonable equation for frost penetration depth and the criterion to identify potentially frost-susceptible soils in present pavement design manuals in Korea. Therefore, adequate pavement design procedures in seasonal frost areas, as well as construction and maintenance practices are required. In this paper, frost penetration depths along national roads in Korea were measured and analyzed over several years. The frost penetration depth was analyzed with respect to the provinces of Korea and sunny/ shaded areas. Additionally, measurement results were compared to the formula of the US Army Corps of Engineers and Ifukube in Japan.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.5
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• pp.487-490
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• 2011

We used X-ray tomography to carry out an experimental study to visualize the effect of freeze and thaw cycles on the gas diffusion layer (GDL) in a polymer electrolyte membrane fuel cell (PEMFC). A PEMFC has freeze and thaw cycles if the fuel cell is operating at a below-freezing ambient temperature. The cycle permanently deforms the fuel-cell capillary structures and reduces the ability of the cell to generate electric power and also reduces its service life. The GDL is the thickest capillary layer in the fuel cell, so it experiences the most deformation. The X-ray tomography facility at the Pohang Accelerator Laboratory was used to observe the structural changes in GDLs induced by a freeze and thaw cycle. We discuss the effects of these structural changes on the power production and service life of PEMFCs.

• Journal of the Korean Geotechnical Society
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• v.26 no.7
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• pp.71-80
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• 2010

Korea is considered to be a seasonal frozen soil area that thaws in the spring, and freezes in winter. In the current design codes for anti-freezing layer, the thickness of anti-freezing layer is calculated by the depth frozen due to the temperature condition. Therefore, there is a tendency of over-design and applying uniform thickness without the consideration of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential to study the structural appropriateness of pavement layer and bearing capacity besides the seasonal and mechanical properties of pavement materials to take an appropriate and reasonable design of the road structure. In this paper, the evaluation of frost susceptibility on subgrade, ant-freezing layer, subbase was conducted by means of the mechanical characteristics and model experiment. The temperature, heaving amount, unfrozen water contents and freezing depth of soil samples, the subgrade, anti-freezing layer, subbase soils of road construction site were measured to determine the frost susceptibility.

• International Journal of Highway Engineering
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• v.12 no.2
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• pp.71-79
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• 2010

The influence of fines of the frost susceptibility of subgrade soils were established by laboratory freezing system test simulating closely the thermal conditions in the field. During the winter season, the climate is heavily influenced by the cold and dry continental high pressure. Because of siberian air mass, the temperature of January is $-6{\sim}-7^{\circ}C$ on average. This chilly weather generate the frost heaving by freezing the moisture of soil and damage potential of the road structure. In the freezing soil, the ice lenses increase the freeze portion of soil by absorbing the ground water with capillary action. However, the capillary characteristics differ from the sort of soil on the state of freezing condition. In the current design codes for anti-freezing layer, the thickness of anti freezing layer is calculated by freezing depth against the temperature condition. Therefore, they have a tendency of over-design and uniform thickness without the considerations of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential for studying the appropriateness and bearing capacity besides the seasonal and mechanical properties of pavement materials to take a appropriate and reasonable design of the road structure. In this Paper, the evaluation of frost susceptibility was conducted by means of the mechanical property test and laboratory freezing system apparatus. The temperature, heaving amount, heaving pressure and unfrozen water contents of soil samples, the subgrade soils of highway construction site, were measured to determine the frost susceptibility.