Prof. D. N. Singh

PADMAKUMAR G P

Ph. D.
Indian Institute of Technology Bombay, Powai, India gppkumar@yahoo.com

LABORATORY INVESTIGATIONS ON HEAT MIGRATION THROUGH SOIL MASS

In many real life situations, the soil mass (both in dry and saturated states) gets exposed to thermal energy field (or thermal gradient), which results in heat migration through it. However, heat migration through the soil mass depends upon its thermal properties (viz., thermal resistivity, thermal conductivity, thermal diffusivity and heat capacity), apart from the characteristics of the heat source (viz., solar ponds, tanks storing heated fluids, buried cables and pipelines, air conditioning ducts, disposal of toxic and hazardous wastes in the geoenvironment, chemical and thermal stabilization of soft and sensitive soils etc.), which in turn depend on the type of the soil, its state of compaction and saturation. Incidentally, migration of heat through the soil mass also leads to moisture movement (or its redistribution). Hence, precise determination of thermal properties of the soil mass, which governs migration of heat and heat induced moisture migration in it, becomes mandatory. In this context, attempts have been made in this study to develop a methodology which facilitates understanding these mechanisms in easy and precise manner. This methodology entails quantification of temporal and spatial variations of the thermal flux and temperature in the soil mass, by conducting real-time flux and temperature measurements with the help of state-of-the-art instrumentation. In addition, a mathematical model PHITMDS (i.e., Prediction of Heat Induced Temperature and Moisture Distribution in Soils), based on equivalent electrical circuit, has been developed and its utility and efficiency for determining heat induced moisture migration in the soil mass has been established. It is believed that this model will be quite useful for designing and safe execution of the above cited projects.