Fractional calculus-based compression modeling of soft clay

Abstract

As a popular tool for characterizing the rheological properties of materials, fractional calculus can be applied to describe soil creeping. This study attempted to analyze the one-dimensional (1D) compression behavior of clay by using fractional calculus. A fractional Merchant model (FMM) was established based on viscoelastic-elastic correspondence principle. This model was successfully applied to fit the oedometer test results of Nansha clay, which is widely spread in the Pearl River Delta, China. It is demonstrated that the fractional derivative-based model was able to characterize the compression behavior of soft clay with fewer parameters than classical rheological models. The relationship between the order of fractional derivative and the compression process of clay was discussed. The order of fractional derivative is observed to decrease as load increases, which implies that the creep behavior of clay became less pronounced with increasing load levels. These findings may open up new avenues for theoretical and empirical modeling of clay compression in the framework of fractional calculus.