TOPOLOGY OPTIMIZATION OF SURFACE STRUCTURES SUPPORTED BY PILE GROUPS

Resumo

This work investigates an aspect of topology optimization strategies in dynamic soil-structure
interaction problems. The aim is to understand the influence of the presence of embedded pile groups in

the optimal shape of a piled structure. The surface structure is modeled by classical three-dimensional fi-
nite elements. The embedded pile group that supports the structure is modeled via the impedance matrix

method. The soil is an isotropic, viscoelastic, layered medium, and the piles are elastic isotropic bodies
with fully bonded contact with the soil throughout their interfaces. Coupling between the structure and
the pile foundation is obtained by establishing direct kinematic compatibility and equilibrium criteria at

discrete nodes of the structure that connect to pile heads. The system is considered to be under arbi-
trary static external loads. Shape optimization of the surface structure is obtained with the bidirectional

evolutionary structural optimization method (BESO), in which elements of the mesh of the structure are
included or removed in order to achieve a certain optimal topology. Objective functions in this work is
the stiffness of the structure. The results compare the difference between the optimized shapes in the
case in which the structure rests on rigid supports, and the case in which energy dissipation to the soil
through the piles is considered.