Methodological issues of soil thermal properties survey during HV cable line pre-design phase

The modern development of the power systems involves the increase of the share of the underground cables. The high voltage cable lines design requires the study of routes to determine the environmental parameters relevant to sizing. The thermal resistivity of the environment in which the cable is buried and the ambient temperature are of critical importance. These parameters largely determine the cost of the cable line construction and optimal operation. This paper deals with the problem of the uncertainty of the assessment of these parameters and the subsequent requirements for the organization of pre-design studies. The significance of the laboratory tests of the underground cables backfilling materials is identified. The present study provides the basis for considering the incorporation of the analysis of the correlation between thermal resistivity and the degree of backfill compaction in the laboratory tests.