An efficient pile-group foundation model to deal with ground-borne vibration problems

Abstract

Abstract This paper proposes a new efficient three-dimensional approach for modelling the dynamic response of pile-group foundations due to man-made ground-borne vibration excitations. The model employs the singular boundary method to account for the soil reaction, whilst the piles are modelled as rod or Euler-Bernoulli beams to account for axial/torsional or bending motions, respectively. The model is formulated considering strong coupling conditions between the two subsystems. The robustness of the model is discussed by comparing its results with the ones obtained by a three-dimensional finite element and boundary element approach. The comparison reveals that the robustness and efficiency of the proposed methodology provide accurate results without compromising its computational efficiency. A study of the dynamic interaction factors employed for modelling large pile-group systems using the superposition method is also presented. Particularly, the influence of including neighbouring piles in the calculation of dynamic interaction factors is discussed in the context of three pile-group foundation cases. This study shows considerable discrepancies above 10 Hz in the prediction of interaction factors between systems that do not consider neighbouring piles with the ones that do.