HEAT CONDUCTION MODEL OF SATURATED SOIL AND ESTIMATION OF THERMAL CONDUCTIVITY OF SOIL SOLID PHASE

This paper reports an investigation into the applicability of the series/parallel model of heat conduction to saturated soils. The model is expressed by the thermal conductivities of solid phase and fluid, volumetric solid content, and D value, which is defined as the contribution ratio of the solid phase to the series flow of heat. The experimental results show that the model can be applied to saturated soils. Both the thermal conductivity of the soil solid phase and the D value of the model can be determined by simultaneous equations that were derived from the model. The thermal conductivity of the soil solid phase, that is, the mean thermal conductivity of the soil solid particles, can be approximated by the weighted geometric mean of the thermal conductivities of each soil solid particle. The thermal conductivities of the solid phases, which were determined by the series/parallel model, were used to calculate de Vries' equation. The calculated values agree well with the measured values. The D values of the model are in the neighborhood of 0.95 for the granular materials and soils used in this work.