Temperature-dependent relationship between the water content and electrical conductivity of soils

Water content is a fundamental parameter for analysing soil composition and engineering behaviour. However, conceptual water content sensors cannot be used in high-temperature and high-pressure environments. To assess the suitability of using electrical conductivity (EC) as a predictor of soil water content at high temperatures, a series of EC and water content tests of clay and sand is conducted. Subsequently, the relationships between EC and water content at different temperatures are analysed. On this basis, the feasibility of eight EC models for predicting soil water content is discussed. The results show that temperature has a vital impact on the EC test of soil and EC is more sensitive to temperature than to dry density and water content. The temperature effect of soil EC is more obvious with an increase in dry density, and EC does not increase monotonically with an increase in temperature. The predicted effect of some EC models tends to be better with an increase in dry density or temperature. This research provides a reference for the EC test and model establishment of high-temperature soils.