Experimental study on the shear characteristics of frozen soil‐concrete interface under the constant normal stiffness

Abstract The interaction between the structure and soil is a crucial factor in infrastructure stabilization in cold region engineering, both transversely and vertically. During interface deformation, the transverse action is reflected in the change of constraints, including normal stiffness, normal stress, and normal volume, while the vertical action is reflected in the change of shear properties. However, the study of different transverse constraints is not systematic, especially considering the normal stiffness and shear properties at different hydrothermal states. This study investigated the shear behavior of the interface between concrete and frozen soil under different normal stiffness, temperature, and water content using the interface direct shear test under temperature‐controlled conditions. The results show that with the increase in temperature and water content, the initial shear stiffness of the interface shear stress‐shear displacement curve gradually increases, and the interface shear strength gradually increases. Different normal stiffnesses have a small effect on the morphology of the interfacial shear stress‐shear displacement curve but significantly affect the peak shear strength. The peak shear strength increases significantly with the increase of normal stiffness, and this trend is more obvious with the decrease in temperature. The corresponding interfacial cohesion and friction angle also increases with the increase in normal stiffness.