Abstract:  In order to explore the mechanism of the effect of temperature changes on the permeability of clayey soil at 5-30 ℃, while considering the fluid properties induced by temperature changes and the influence of soil deformation on the hydraulic conductivity, and improve the application range and accuracy of the model, in this paper combination of laboratory experiments and theoretical models were used to study. Then, based on the experimental data of variable temperature seepage, a relationship equation between soil strain and medium void ratio was constructed. Finally, further modifications were made to the modified model of the Kozeny Carman model (REN model). The results show that in the common temperature range of 5-30 ℃ in groundwater, the deformation of soil caused by temperature changes has a significant impact on the hydraulic conductivity of clayey soil. The maximum calculation error of hydraulic conductivity can reach 40% under considering only the variation of fluid viscosity with temperature and ignoring the effect of clayey soil deformation. The modified model has better performance compared to existing hydraulic conductivity models. Through the analysis of the modified hydraulic conductivity model, it was found that the main controlling factor for the change in hydraulic conductivity is fluid viscosity when the temperature is in the range of 5-20 ℃, and has a small impact on the hydraulic conductivity with a degree of less than 10%. When the temperature is in the range of 20-30 ℃, the contribution rate of hydraulic conductivity induced by soil deoformation caused by temperature increase, and an maximum impact on the hydraulic conductivity exceeding 40%.

Key words:  , hydraulic conductivity, saturated clayey soil, temperature, deformation, void ratio, Kozeny-Carman model, REN model