Experimental study on thermal properties of frozen soils

Abstract

A series of measurements of the effective thermal conductivity, specific heat and unfrozen-water content of various soils exposed to a cold environment have been carried out by a transient probe method and a calorimetric technique. The present experiments were performed at a very slow rate of cooling of the moist-soil and using four kinds of soil samples from fine to coarse grain-size. It was established that the amount of unfrozen-water in the frozen soil was dependent on the initial moisture content, the grain-size of the soil and the temperature (below 0°C). Measured values of the effective thermal conductivity and specific heat show a strong dependence on temperature, initial moisture content and grain-size of soil in the temperature range T = 0°C to −10°C. The anomalous behavior of a decrease in the effective thermal conductivity of frozen soil for the finest grain-size with decreasing temperature (below 0°C) was observed for a large initial moisture content w = 30–40%.