Finite element simulations of the behavior of piled-raft foundations using a multiphase model


Correspondence to: Patrick de Buhan, Université Paris-Est, Laboratoire Navier, Ecole des Ponts ParisTech–IFSTTAR–CNRS, 6–8 Avenue Blaise Pascal, 77455 Marne-la-Vallée Cedex 2, France.



Finite element simulations of the behavior of a piled raft foundation have been carried out using a multiphase model conceived as an improved homogenization approach. According to this model, the ground reinforced by a group of piles is treated as a homogeneous continuous medium. In this approach, no specific interface elements are necessary to account for the mechanical interaction between the piles and the ground: this interaction is described by means of two scalar parameters, one stiffness parameter and one which can easily be derived from the maximum ground-pile friction. The implementation of the model into a finite element code provides an efficient tool for the analysis of the influence of the pile number or length on the settlement and bearing capacity of a square piled raft foundation and of the way the total applied load is shared between the raft and the piles. Results are compared with a standard 3D finite element analysis. The comparison highlights the fact that the proposed approach remains to be improved to account for tip resistance. Copyright © 2012 John Wiley & Sons, Ltd.