THERMO-OSMOTIC AND THERMOELECTRIC COUPLING IN SATURATED SOILS

THERMALLY INDUCED FLOWS OF MOISTURE AND ELECTRICITY IN SATURATED CLAYS WERE MEASURED EXPERIMENTALLY AS THE WATER CONTENT, EXCHANGE CAPACITY, AND PORE-WATER ELECTROLYTE CONCENTRATION WERE SYSTEMATICALLY VARIED. PRIOR WORK ON THERMO-OSMOSIS IN SOILS IS REVIEWED, AND POSSIBLE COUPLING MECHANISMS ARE DISCUSSED IN THE LIGHT OF NEW EXPERIMENTAL RESULTS. THE CLAY-WATER SYSTEMS STUDIED EXHIBITED CHARACTERISTIC THERMOELECTRIC AND THERMO-OSMOTIC EFFECTS. MEASUREABLE CURRENTS ON THE ORDER OF 1 TO 10 MICROAMPERES PER DEG C PER CM WERE DETECTED, WITH THE WARMER SIDE HAVING THE MORE POSITIVE POLARITY. THE THERMOELECTRIC CURRENT INCREASED CONSISTENTLY WITH INCREASING WATER CONTENT, EXCHANGE CAPACITY, OR ELECTROLYTE CONCENTRATION IN PORE WATER. THERMO-OSMOTIC PRESSURES ON THE ORDER OF A FEW TENTHS OF A CENTIMETER OF WATER PER DEGREE CENTIGRADE WERE MEASURED WITH NET FLOW OCCURRING TO EITHER THE WARM OR COLD SIDE. THE PECULIAR TEMPERATURE-DEPENDENCE OF ACTIVITY COEFFICIENTS OF ELECTROLYTES IN THE PORE WATER IS SUGGESTED AS A POSSIBLE EXPLANATION FOR A GIVEN DIRECTION OF MOISTURE FLOW. THERMAL CONTRIBUTIONS TO MOISTURE MOVEMENT IN SATURATED SOILS ARE MINOR COMPARED TO THERMAL MOISTURE FLOW IN PARTIALLY SATURATED MEDIA. /AUTHOR/

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 66-77
  • Monograph Title: Effects of temperatures and heat on engineering behavior of soils
  • Serial:

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Filing Info

  • Accession Number: 00237756
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Aug 25 1994 12:00AM