Numerical studies on the effect of temperature on the unsaturated hydraulic response of geotextiles
A series of coupled thermo-hydraulic simulations were performed on a soilgeotextile column to understand the effect of temperature on suction distribution throughout the soil column and on the hydraulic performance of the geotextile as a drainage/capillary barrier layer. Two different constant temperatures of 0C and 38C and a temperature gradient of 4C along the column were modeled. Changing the temperature from 0C to 38C did not have a significant effect on the suction head distribution in the soilgeotextile column. The temperature gradient resulted in appreciable thermal vapor flow and changes in suction head and hydraulic conductivity of the geotextile. During drainage, the temperature gradient and lower temperature at the top of the column increased suction in the geotextile and its ability to function as a capillary barrier. During capillary rise, the temperature gradient and lower temperature at the top of the column decreased the suction in the geotextile and its ability to function as a capillary barrier. Changing the direction of the thermal gradient reversed the water vapor flow direction and its effect on the suction in the geotextile. A temperature gradient did not have a noticeable effect on the suction head of the geotextile when positive pore pressure was developed in the geotextile and adjacent soil during drainage.
capillary barrier geosynthetics unsaturated flow thermohydraulic behavior