Solução ótima para tabuleiro de pontes rodoviárias com vigas tipo I pré-moldadas e protendidas

Abstract

The bridges are elements of great impact when it comes to road infrastructure, as they have a high cost and require detailed planning. Therefore, projects with optimized solutions have attracted more and more researchers in the area of Structural Engineering, in order to obtain quick and economical solutions. In this sense, the present work aims to present a methodology for obtaining an optimal solution of the superstructure of road bridges with multiple isostatic beams of type I cross section, in precast concrete with straight ropes. For this, we applied advanced optimization techniques based on Genetic Algorithms and computational programming in the C ++ language. In addition, the Fauchart Method and the Direct Stiffness Method were adopted in the computational implementation, with a subsequent step of validation by Finite Element. Class 45 bridges with 13 m wide and spans of between 15 m and 30 m were considered. The performance and economy provided by a profile obtained through optimization with a commercially adopted section was compared. The results evidenced the need to apply optimization processes for the pre-dimensioning of road bridges with multiple isostatic beams, focusing on the choice of cross-section dimensions of the longitudinal members, the number of longitudinal members composing the section of the bridge and the concrete strength adopted.