A generalized relationship to estimate thermal resistivity of soils

Abstract

Soil thermal resistivity plays an important role in the design and laying of high-voltage buried power cables, oil and gas pipelines, nuclear waste disposal facilities, ground-modification techniques employing heating and freezing, etc. For these situations, it is important to estimate the resistance offered by the soil mass in dissipating the heat generated. Several investigators have tried to develop mathematical and theoretical models to estimate soil thermal resistivity. However, these models are not always capable of predicting thermal resistivity of soils. This is mainly due to the fact that thermal resistivity of soil is a complex phenomenon that depends upon various parameters, viz. type of the soil, particle-size distribution, compaction characteristics, etc. As such, none of the relationships available in the literature are suitable for estimating the thermal resistivity of all soils. This paper deals with the details of fabrication of a "laboratory thermal probe" which has been used to evaluate thermal resistivity of various soils. A relationship has been proposed to estimate thermal resistivity of soils depending upon the moulding moisture content and density of the soils.Key words: thermal resistivity, laboratory thermal probe, black cotton soil, fly ash, sands, silty sand.