Response evaluation of axially loaded fixed head pile groups using 3D nonlinear analysis

The aim of this paper is to evaluate the influence of the interaction between the piles of a group fixed in a rigid head on both its bearing capacity and the stiffness of the group. For this purpose, a parametric three-dimensional nonlinear numerical analysis was carried out for different pile group arrangements. The responses of the pile groups are compared to that of a single pile established from pile test results in conjunction with numerical assessment. The bearing capacity efficiency factor is then evaluated, while the stiffness efficiency factor is determined as a function of the deformation level. The influence of the number of piles, the spacing and the deformation level to the group response is discussed. Furthermore, the contribution of the piles constituting the group to the total group resistance is examined and its variability with the settlement level is established. Finally, a relationship is proposed allowing a reasonable prediction of the response of fixed pile groups in similar soil profile conditions.