Design optimization of cable-stayed bridges

Abstract

The goal of this thesis is to achieve a basic understanding of cable-stayed systems. Issues to be treated are the diachronic evolution of cable-stayed bridges, including the advantages, the limitations and the basic design concepts of these indeterminate systems. During this project, the design of typical cable-stayed bridges is optimized with computer-based simulation capabilities contained within the SAP2000 computer software system. The analysis strategy starts with the analyses of ten different 3D models under earthquake loading. The numerical results of the analyses form the basis for the optimization of the bridges' designs. This study has indicated that for the specific design examined, the optimum cable spacing is: 13.2m and 12.39m for equivalent steel decks with bending rigidities of IEequiv=3.25*105 kN*m2 and IEequiv=2.25*105 kN*m2 respectively. The procedure also identified the advantage of using bracing on the top half of the towers. The final part of this thesis concerns a case-study of the Rion-Antirion cable-stayed bridge. This includes the creation of an appropriate computer model as well as the proper examination of the quasi-static behavior of the bridge.