Abstract: The development of landslide deformation usually goes through a certain period of time. At the same time, landslide soil is often in a non-saturated state under rainfall and reservoir water level fluctuation. Constructing a creep model of unsaturated soil in consideration of the matric suction is of vital significance. In this research, a creep model of unsaturated soil for a landslide in the Three Gorges Reservoir area is built based on Burger’s model and assumptions of the mechanics of unsaturated soil. In subsequence, the model parameters were solved using nonlinear regression algorithm, and the model’s rationality was verified by comparing predicted values with experimental values. Finally, in the light of the linear correlation between model parameters and net confining pressure, the model was further modified and the validity of the modified model was verified. The constructed creep model of unsaturated soil well reflects the unsaturated creep behavior of soil in the sliding zone of the landslide, thus is of great significance in predicting the long-term deformation of the landslide.

Key words: unsaturated soil, landslide deformation, Burger’s model, creep model, nonlinear regression algorithm