Abstract: The research on the behavior of the interface between the structure and the plateau frozen soil can play a reference significance for the construction of the pile foundation in high altitude and cold regions. To analyze the influence of the soil water content on the interface shear properties, the shear tests of the interface between the plateau soil and the steel under different water content were performed. The results show that when the water content of the soil is less than the optimal water content, the shear stress increases first and then stabilizes with the shear displacement. The shear stressshear displacement relationship can be expressed by the exponential function. When the water content is greater than the optimal water content, the shear stress shows the relationship of the strengtheningattenuationresidual stability, and the shear stress-shear displacement relationship can be expressed by the piecewise function. The interface shear strength and the residual strength increase with the normal stress, and first increase and then decrease with the water content. With the increase of water content, the interface friction angle decreases gradually, and the interface cohesion reaches the maximum near the optimal water content.

Key words: Interface Shear, Steel, Plateau Frozen Soil, Interface Shear Strength, Exponential Function, Piecewise Function