Optimization of cable-stayed bridges with box-girder decks

Box-girder decks are very effective solutions for long span cable-stayed bridges, due to its high torsional stiffness and streamlined profile, which usually leads to a good aerodynamic behaviour. A study on the optimization of such structural system is presented in this paper. The deck is modelled through the assembly of planes of plate-membrane elements. A multicriteria approach is considered for the optimization itself, with constraints on maximum stresses, minimum stresses in stays and deflections under dead load condition Two illustrative examples are shown.