• Title/Summary/Keyword: road freezing

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Analysis on Freezing Reduction of Road Tunnels with Heat Insulation Method during Winter (단열공법이 적용된 겨울철 도로터널의 동결저감 효과 분석)

  • Son, Hee-Su;Jun, Kyoung-Jea;Yune, Chan-Young
    • Journal of the Korean Geotechnical Society
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    • v.33 no.8
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    • pp.17-27
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    • 2017
  • Gangwon province which is located in northeast of Korea is the coldest region where average daily temperature is below zero during winter while the other regions are above zero. However, there have been insufficient researches on the insulation design and the effect of the insulation on the freezing damages, even though freezing damages were reported consistently in the lining of road tunnel during winter. In this study, to investigate the effect of insulations on the reduction of freezing damages, numerical analysis was performed considering geotechnical and meteorological characteristics in Gangwon province during winter. As a result, it was found that thickness of concrete and shotcrete in lining had negligible effect on the freezing depth while the insulation had significant effect on it. In addition, because the freezing depth is greatly affected by the thermal conductivity of the ground behind the lining in the period of cold weather, these effects should be considered in the estimation of the insulation thickness.

Analysis of Geothermal Melting System Conductivity for Improving Road Safety (도로주행 안정성 향상을 위한 지열 융설시스템 열전도 분석)

  • Lee, Seok-Jin;Kim, Bong-Chan;Lee, Seung-Ha;Seo, Un-Jong;Kim, Jin-Han;Lee, Joo-Ho
    • Journal of Korean Society of societal Security
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    • v.3 no.1
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    • pp.43-50
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    • 2010
  • Sliding accidents on the road have a high percentage by road freezing, especially, they often have appeared at bridges and Tunnel of freezing areas. Thus, the stability of road operations is enhanced by preventing partial freezing phenomenon. According to the geothermal snow melting system analysis, a pattern of thermal conductivity is found out; pavement materials of concrete and asphalt where the system is buried. The heat transfer simulation is essential when the geothermal snow melting system is applied according to heating exchanger pipe placed in the lower pavements. The model tests are conducted on low temperature in freezer using the manufactured test model which is equal to pavement materials. Many variables are discovered from numerical analyses under the same conditions with model test.

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A Study on Snow Melting System for the Anti-freezing Testing Road (시험선로 결빙방지를 위한 융설시스템에 관한 연구)

  • Han, K.I.;Lee, A.H.;Cho, D.H.
    • Journal of Power System Engineering
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    • v.10 no.1
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    • pp.34-40
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    • 2006
  • The snow melting system by electric heating wires which is adopted in this study is a part of road facilities to keep surface temperature of the road higher than freezing point of water for melting the snow accumulated on it. The system is designed to increase traffic safety and capacity. The electric heating wires are buried under paved road at a certain depth and operated automatically and manually. Design theory, amount of heating, and installation standard vary according to economic situation, weather condition, and installation place where the system applies. It is tried to figure out that the appropriate range of required heat capacity and installation depth and intervals for solving snowdrifts and freezing problems with the minimum electric power consumption. The most important factors to design the system are calculation of heating capacity depending on weather condition and depth and interval of the electric heating wires depending on air condition respectively. The study were performed under the range of the air temperatures($-2^{\circ}C,\;-5^{\circ}C,\;-8^{\circ}C$), the intervals of the electric heating wires(70mm, 100mm, 125mm), and the installation depths(50mm, 70mm, 100mm). The ready made commercial program package was used to verify the experimental results.

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The Frost Heaving Characteristics of Subgrade Soils Using Laboratory Freezing System (실내동결시스템을 이용한 노상토의 동상 특성)

  • Shin, Eun-Chul;Ryu, Byung-Hyun;Park, Jeong-Jun
    • 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.

Finite Element Analysis of Structural Performance of Anti-Freezing Layer via the Korea Pavement Research Program (한국형포장설계프로그램 및 유한요소해석을 이용한 동상방지층의 구조적 성능 평가)

  • Kim, Dowan;Lee, Junkyu;Mun, Sungho
    • International Journal of Highway Engineering
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    • v.18 no.2
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    • pp.83-90
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    • 2016
  • PURPOSES : Nowadays, cavity phenomena occur increasingly in pavement layers of downtown areas. This leads to an increment in the number of potholes, sinkholes, and other failure on the road. A loss of earth and sand from the pavement plays a key role in the occurrence of cavities, and, hence, a structural-performance evaluation of the pavement is essential. METHODS: The structural performance was evaluated via finite-element analysis using KPRP and KICTPAVE. KPRP was developed in order to formulate a Korean pavement design guide, which is based on a mechanical-empirical pavement design guide (M-EPDG). RESULTS: Installation of the anti-freezing layer yielded a fatigue crack, permanent deformation, and international roughness index (IRI) of 13%, 0.7 cm, and 3.0 m/km, respectively, as determined from the performance analysis conducted via KPRP. These values satisfy the design standards (fatigue crack: 20%, permanent deformation: 1.3 cm, IRI: 3.5 m/km). The results of FEM, using KICTPAVE, are shown in Figures 8~12 and Tables 3~5. CONCLUSIONS: The results of the performance analysis (conducted via KPRP) satisfy the design standards, even if the thickness of the anti-freezing layer is not considered. The corresponding values (i.e., 13%, 0.7 cm, and 3.0 m/km) are obtained for all conditions under which this layer is applied. Furthermore, the stress and strain on the interlayer between the sub-grade and the anti-freezing layer decrease gradually with increasing thickness of the anti-freezing layer. In contrast, the strain on the interlayer between the sub-base and the anti-freezing layer increases gradually with this increase in thickness.

The statistical factors affecting the freezing of the road pavement (도로포장체의 동결에 영향을 미치는 통계적 요인)

  • Kim, Hyun-Ji;Lee, Jea-Young;Kim, Byung-Doo;Cho, Gyu-Tae
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.1
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    • pp.67-74
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    • 2016
  • Due to the character of the climate of Korea, the pavement of a road is Influenced by freezing in winter season and thawing in thawing season. In the last few years, several articles have been devoted to the study to minimize the damage of freezing and thawing action. The purpose of this paper is to identify appropriacy of factors that influence road pavement thickness. We conduct the decision tree analysis on the field data of road pavement. The target variable is 'Frost penetration'. This value was calculated from the temperature data. The input variables are 'Region', 'Type of road pavement', 'Anti-frost layer', 'Month' and 'Air temperature'. The region was divided into 9 regions by freezing index $350{\sim}450^{\circ}C{\cdot}day$, $450{\sim}550^{\circ}C{\cdot}day$, $550{\sim}650^{\circ}C{\cdot}day$. The type of road pavement has three-section such as area of cutting, boundary area of cutting and bankin, lower area of banking. As the result, the variables that influence 'Frost penetration' are Month, followed by anti-frost layer, air temperature and region.

Characteristic of Elastic Paving Materials in Bicycle Road using Polyurethane (폴리우레탄을 이용한 자전거도로의 탄성포장재 특성)

  • Lee, Young-Sei
    • Journal of the Korean Society of Industry Convergence
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    • v.17 no.1
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    • pp.7-14
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    • 2014
  • In this study, characteristic of elastic paving materials in bicycle road using polyurethane were studied experimentally. As a results, following their good result was obtained. Bicycle road packaging materials are flexural strength g test, ratio of mass change after freezing and thawing, repulsion elasticity test, water Permeation coefficient test and slip resistance test results showed good performance.