Abstract: The creep behaviors of saturated saline soil are studied in the consolidation creep test under isothermal conditions in this paper. Based on the element model, the fractional creep model of saturated saline soil was established by introducing Abel dashpot and osmotic suction. The phenomenological correlation between salt content and creep behavior of saturated saline soil is discussed. The effects of osmotic suction on the ratio of the secondary compression coefficient to the compression index, initial shear modulus and initial shear strain are analyzed by combining experimental results with fractional model fitting. The fractional order model is fitted by the test results of different stress levels and salt content. The validity of the model is verified by the viscosity coefficient formula. The results show that the ratio increases exponentially as the osmotic suction increases. The initial shear modulus decreases as the osmotic suction increases, and the initial shear strain exhibits a linear relationship with the osmotic suction. Comparing with the integer element model, the fractional creep model proposed in this paper is more suitable for predicting the creep behavior of saturated saline soil. Combined with the results of experiments and model analysis, it is found that the increase of salt content promotes the creep behavior of saline soil.

Key words: saturated saline soil, triaxial creep test, osmotic suction, theoretical model, creep characteristics