Creep modelling of soft soil based on the fractional flow rule: Simulation and parameter study

摘要

The creep deformation of soft soil is a critical factor in geotechnical design of engineering facilities built on soft soil foundations. In this study, a novel fractional creep model for soft soil is developed by introducing the Almeida fractional derivative into the classic elastic-viscoplastic model. A series of numerical analyses are conducted to determine the kernel function of the proposed model with the best performance, and the good agreement between the model predictions and test results is observed. With the advantage of introducing the fractional flow rule, the fractional creep model exhibits higher accuracy and convenience than conventional models as fewer material parameters and state variables are required. Furthermore, a parameter study reveals that the fractional order directly relates to the stress level, and the different deformation patterns of soft soil under low and high stresses could be reflected by the tendency of the order. (C) 2021 Elsevier Inc. All rights reserved.