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Resumo:
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Cable stayed bridges emerged as an effective alternative to transpose large spans, allowing the use of slender, lightweight and economical structures. Due to the evolution of technology and materials, there are many possible structural designs, either in the geometry, shape or element layouts. Therefore its necessary to comprehend potencial arrangements of the elements, aiming the resources optmization and a good global load distribution. In this regard, the present paper proposes a behavior analysis of different cable systems for a cable stayed bridge, carrying dead and traffic loads, which follow Brazilian technical standards. The project of the Anita Garibaldi cable stayed bridge in the city of Laguna, Santa Catarina state, Brazil, was used as a basis for the models. First, the stays longitudinal distribution was modeled in a semi-harp system, used in the original project, also the harp and fan systems. The study regarding those three models was divided in two phases: at the first phase, these were simulated without the use of transverse cables; in the second, these transversal cables were inserted. Those circumstances were modeled using a computational tool based on finite elements method, the Structural Analysis Program 2000 (SAP2000). A comparative analysis was made according to the structure’s global behavior, diagrams of bending moments, axial force, torsion, and global displacements. With these results, the semi-harp distribution was granted as an applicable solution, as it shows regular results between the harp and fan systems, bringing together the qualities of both. The addition of the transverse stays in the second phase models reduces pylon’s global displacements and the torsions on the deck. |
