A simple rheological element based creep model for frozen soils

Creep of frozen soils is one of the most important issues in cold regions engineering. This paper first reviews the state-of-the-art of creep models for frozen soils. It is found that the elementary rheological models are more feasible in describing the creep of frozen soils. The authors propose a simple model by combining Maxwell, Kelvin and Bingham body, with a parabolic yield criterion. The model is verified by the direct shear creep tests on frozen fine sand, and the calculated creep strains agree in general with test data. A field loading test in Beiluhe site along Qinghai-Tibet railway is modeled on FLAC platform with the proposed model and the simulated settlement of underlying warm and ice-rich permafrost well coincide with the in situ monitored data.