Viscoelastic–plastic creep constitutive model of frozen soil

In accordance with the twin-shear unified strength theory and the improved Nishihara model, a viscoelastic–plastic creep constitutive function of frozen soil has been established based on the associated flow rules, and the viscoelastic–plastic soft matrix is further derived from numerical calculations. The results show that the viscoelastic–plastic creep constitutive function has considerable influence on the non-linearity and the intermediate principal stress of materials, and it can describe the creep properties of frozen soil as a unified solution. The proposed model herein is applicable to the creep study of frozen soil.