Fractional time-dependent merchant model for coastal soft clay

Soft clayey soils behave a time-dependent creep property subjected to sustained load. In order to describe the stress-strain-time property of soft clayey soil, a time-based fractional creep constitutive model is proposed based on the Caputo fractional calculus by applying the Abel dashpot in classical component model. The proposed fractional Merchant model is validated by drained creep test of coastal soft clay. The model parameters are obtained by fractional nonlinear fitting in terms of drained creep test results of coastal soft clay. Then the predicted results by the proposed fractional Merchant model and classical component models are also compared and validated with creep test results. It shows that the proposed fractional Merchant model is more approached to drained creep test results than classical component models. In particular, the proposed fractional Merchant model could well reduce the errors in the initial phase of creep compared with the classical model. It is indicated that the fractional Merchant model is superior in predicting drained creep property of coastal soft clay.