Application of the Fractional Viscoelastic Model in Interaction of Saturated Soft Soils and Piles

Abstract:

To describe the viscoelastic characteristics of saturated soft soils， the fractional Merchant model is introduced， and the stress-strain relationship in the transformed domain is derived through integral transforms. Based on the elastic-viscoelastic correspondence principle， the solution of the fractional transversely isotropic viscoelastic saturated soft soils is obtained， which is the kernel function of the boundary element solution for the soils. Based on the stiffness matrix of a 2-noded pile element subjected to axial loading， the finite element solution for the pile is constructed. The boundary element solution for the soils is coupled with the finite element solution for the pile to solve the interaction between the soils and piles. Several examples are designed to verify the presented theory and to analyze the influence of the fractional order on the pile-soil interaction.

Key words:saturated soft soils;axially loaded piles;fractional derivative;transverse isotropy;viscoelasticity;boundary element-finite element coupling method