Journal of the Korean Geosynthetics Society (한국지반신소재학회논문집)

Korean Geosynthetics Society (한국지반신소재학회)
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Experimental and Numerical Investigation of the Performance of Vertical Thermosyphon for Frozen Ground Stabilization

실험과 수치해석을 통한 동토지반 안정화용 수직형 열사이펀의 성능평가

  • Lee, Jangguen (Geotechnical Engineering Research Division, SOC Research Institute, Korea Institute of Civil Engineering and Building Technology) ;
  • Lee, Chulho (Geotechnical Engineering Research Division, SOC Research Institute, Korea Institute of Civil Engineering and Building Technology) ;
  • Jang, Changkyu (University of Science and Technology) ;
  • Choi, Changho (Geotechnical Engineering Research Division, SOC Research Institute, Korea Institute of Civil Engineering and Building Technology, Geo-space Engineering Dept., University of Science and Technology)
  • Received : 2014.09.29
  • Accepted : 2014.11.07
  • Published : 2014.12.30
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Abstract

Frozen ground in cold region consists of an upper active layer and lower permafrost which is permanently frozen land. During the summer season, the air temperature is high enough to make the frozen ground melt, which causes the reduction of soil strength and thaw settlement. These phenomena result in structural instability, so it is necessary to apply frozen ground stability techniques. Thermosyphon is a closed natural two-phase convection device to maintain the ground temperature below $0^{\circ}C$ by extracting heat from the ground and discharges it into the atmosphere. Experimental and numerical investigation has been performed to estimate the effect of the refrigerant filling ratio in thermosyphon using R-134a refrigerant and the thermal conductance of the thermosyphon.

한대지역은 계절 변화에 따라 동결융해가 반복되는 상부의 활동층과 하부의 영하상태로 항시 유지되는 영구동토층으로 구성되어 있다. 한대지역에서 여름철에는 동결되어 있는 지반을 융해시키기 때문에 지반 강도저하 및 침하가 발생한다. 이러한 강도저하 및 침하는 상부 구조물의 구조적 안정성에 문제를 야기시켜 활동층을 포함하고 있는 한대지역에서는 지반의 온도를 항시 영하상태로 유지할 수 있는 동결지반 안정화 공법이 필요하다. 열사이펀이란 구조체 내부에 충전된 냉매의 자가적인 열순환에 의해 지반의 온도를 항시 영하상태로 유지할 수 있는 지반 안정화 공법 이다. 본 연구에서는 열사이펀의 지반 동결성능을 분석하기 위해 R-134a 냉매를 이용하여 충전율에 따른 열사이펀의 지반 온도제어를 실내실험과 수치해석을 통해 분석하고 열사이펀의 열전도율을 산정하였다.

Keywords

References

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