The structure is in concrete . Prior to the design has been conducted a pre-design face to the determination of the centers of mass and stiffness for each deck , so as to be able to classify the structure as regular in plan , and to the determination of vertical elements classified as secondary ( pillars ) and main ( septa ) , in order to reasonably rely seismic actions solely to the latter. The coverage of irregular shape and free of internal pillars , has been shaped in part like concrete plate
