Experimental study for drying-out of soil around underground power cables

Six types of soil are investigated for studying the drying-out phenomenon and the thermal behavior of the soil around power cables. Grain size distribution and permeability and compaction tests are carried out for these six types of soil. The measured pF-curves and the recorded distributions of temperature with both time and distance at the stated conditions are presented. The distributions of moisture with distance are given. From the analysis of the temperature and moisture distributions with distance, it is found that some soil points of rapidly increased temperature have approximately zero moisture content. The drying-out phenomenon starts at 55°C in sand 2 and at 58°C in sand 1 and sand 3. During heating processes it was noticed that some types of sand lose their moisture content, in comparison with other sand types. The results of the field study show that drying-out could occur during July and August