The creep characteristics of frozen soil has significant influences on infrastructure stability in cold regions. It is important for frozen ground engineering to describe the creep properties of frozen soil with accurate models. In this research, a new structure creep model is developed by considering the hardening factor and damage factor which play different roles during various creep stages. According to the experimental results under different stress levels, the proposed model was verified. The calculation results exhibit the proposed model has abilities to predict the creep characteristics of frozen soils, especially the nonlinear stress-strain behavior at acceleration creep stage.

As the weakest segment within frozen soil, the interface between ice and frozen soil undertakes the link of load transmission. The mechanical parameters between ice and frozen soil influence the deformation and strength of frozen soil. To investigate the mechanical behaviors of ice-frozen soil interface, the cryogenic direct shear tests were carried out and the deformation, strength properties of interface were analyzed. The shear stress of interface was described by generalized hyperbolic model and the physical meaning of the model parameters were defined. Based on the generalized hyperbolic model, the shear stiffness of interface was derived. The effect of temperature on the strength, shear stiffness of interface under different initial moisture contents, initial void ratios and normal stresses were discussed. The three-dimensional finite element model was established using COMSOL Multiphysics, and the mechanical behaviors of ice frozen soil interface were researched.