Unsaturated creep tests and empirical models of the sliding zone soils of the Qianjiangping landslide in Three Gorges

Creep of sliding zone soils may cause significant displacement in large-scale landslides in Three Gorges Reservoir Area. To investigatewater effects on the creep behavior of the Qianjiangping Landslide, a series of unsaturated triaxial creep tests of the sliding zone soils were performed. Based on the analysis of the test results, a new stress intensity incorporating matric suction is defined and an unsaturated Singh-Mitchell creep model is developed. In addition, interrelation among parameters of the model, stress and time is analyzed quantitatively to modify the model. Predicted results are in good agreement with the experimental results, which indicates that the established unsaturated model can reasonably simulate the effects of water on the soil creep behavior of the Qianjiangping Landslide. This study provides a calculation model and parameters for the evaluation of long-term stability of landslides under the influence of rainfall and reservoir water fluctuation.