MOISTURE-TEMPERATURE RELATIONSHIPS IN A SAND DUE TO OUTWARD, RADIAL FREEZING. FINAL REPORT

A "clean" sand is commonly specified as backfill around the evaporator section of thermosyphons designed to maintain the thermal regime of perennially frozen, thaw-unstable soils. A series of laboratory tests was performed to determine the magnitude of moisture migration. The test results indicate the moisture migration can result due to outward radial freezing in a nonfrost susceptible sand possessing a low to moderate degree of saturation. Moisture did not migrate when the sand was saturated prior to freezing. The redistribution of moisture changes the thermal properties of the soil system which affects the maximum radius of freezing by desiccating soil at the outermost radius of influence and increasing the degree of saturation around the evaporator. The desiccated soil region will experience an accelerated rate of thaw due to a lower volumetric latent heat of fusion. In addition, the radius of freezing is reduced as moisture migrates towards the evaporator section. These effects warrant additional considerations that must be addressed when designing refrigerated foundations with thermosyphons.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 164 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00607551
  • Record Type: Publication
  • Source Agency: Alaska Department of Transportation and Public Facilities
  • Report/Paper Numbers: AK-RD-90-15
  • Files: TRIS, STATEDOT
  • Created Date: Apr 30 1991 12:00AM