A new one-dimensional consolidation creep model for clays

Creep deformation is a prevalent form of deformation infill projects, and accurately characterizing the creep of fill soils is essential for ensuring the safe and reliable operation of these projects. To develop a novel variableorder fractional creep model that describes the consolidation creep behavior of fill soils, this research enhances the fractional order algorithm to achieve more precise fractional orders and determine the variable order function. Consequently, a novel variable-order fractional element featuring viscoelastic memory effects is introduced and formulated as a model. Unlike the traditional Maxwell model, the new model is simpler, has fewer parameters, and includes a memory effect that reveals the characteristics of mechanical properties over time during the creep process. In addition, this study validates the proposed model's applicability and modeling benefits through one-dimensional consolidation creep tests on red clay at the fill site. The findings indicated that the change in fractional order in the new model should be an exponential function. The trend of decreasing fractional order with time is consistent with the soil consolidation creep-hardening behavior, suggesting that the variable fractional order function represents the changing nature of the soil. In this study, exploring fractional order laws reveals the physical significance of the fractional order element and enables the composed model to make effective predictions of relevant working conditions.