Evaluation of thermal resistivity of soils in Saudi Arabia

Abstract

The thermal behavior of a number of soils obtained from Eastern region and Riyadh area including those frequently used for high voltage cable backfills has been studied. Thermal resistivity tests using a thermal needle method were carried out in the Laboratory.

The factors influencintg the thermal resistivity of soils are presented in terms of a geotechnical approach and discussed in the light of findings of an experimental study. The system developed to evaluate the thermal properties of soils is presented with the results of this study. Results suggest that most of natural soils studied have high thermal resistivity in a dry state and indicate the need for developing thermal backfills having low thermal resistivity.

The thermal behavior of a number of made up backfills consisting of different proportions of cement, clay, limestone dust and marl has been studied. From these tests, it was found that sand-clay additives behaved the best. A fine limestone dust, a by-product from rock quarries, was found to have highly desirable thermal properties.