A 3D numerical model for the dynamic analysis of pile groups with inclined piles

The paper presents a numerical model for the kinematic interaction analysis of inclined pile groups; piles are modelled with beam finite elements and the soil is schematized with independent horizontal infinite layers. The pile-soil-pile interaction and the radiation problem are accounted for by means of elastodynamic Green's functions. Piles cap is considered by introducing a rigid constraint; the condensation of the problem permits a consistent and straightforward derivation of both the impedance functions and the foundation input motions which are necessary to perform the inertial soil-structure interaction analyses, according to the substructure approach. The model, which also allows evaluating the kinematic stress resultants in piles resulting from the propagation of seismic waves in the soil, is validated performing accuracy analyses and comparing results, in terms of dynamic impedance functions, kinematic response parameters and pile stress resultants, with those furnished by 3D refined finite element models.