Buried electric cables and their bedding are at common installation depths almost exclusively located in unsaturated soil above the ground water table. Since cable-bedding and soil are in a direct capillary contact, the water content and consequently the thermal properties of bedding materials can be subject to both changes of weather and load conditions during operation of the underground cable system. In order to quantify these processes, the thermal, hydraulic and geotechnical properties of soils and bedding materials are investigated in laboratory and field experiments. Furthermore a large field experiment (cable test site) was built at TU Darmstadt in 2013 to analyze the heat and mass transport around the cables in real scale. The data collected by the laboratory experiments and the cable test side are finally used to validate coupled numerical models.