Effect of temperature on water retention phenomena in deformable soils: theoretical and experimental aspects

In this paper, a theoretical and experimental investigation of the effect of temperature on water retention phenomena in deformable soils is presented. A general law expressing the change in suction with water content, temperature and void ratio is proposed theoretically. This law accounts for the influence of density and temperature on water retention. It also provides a general framework which appears to be well-adapted to describe many particular cases. The effect of temperature is studied through a predictive relationship which is established in this framework. This relationship allows us to obtain the water retention curve at any temperature from that at a reference temperature, thus reducing strongly the number of tests required to characterize the thermo-hydraulic behaviour of a soil. The relevance of this relationship was experimentally verified from new tests as well as the results previously reported in the literature. The new tests were performed on two model media, namely, a terracotta ceramic and a clayey-silty sand. The tests taken from the literature concerned two different clays. Comparison between theoretical prediction and experimental data was particularly promising and shows the capability of the model to cover a wide range of soils.