Avaliação da influência das curvaturas e das transversinas na distribuição do momento fletor devido à carga móvel em pontes curvas de concreto armado

Abstract

The structural analysis of bridges with curved longitudinal geometry presents greater complexity when compared to with straight bridges. This fact is due to a series of consequences caused by the interaction between the bending moment and the torsion moment. This makes torsion requests considerable, where they can condition the dimensioning and stability of the structure, as well as causing the increased distortion of the cross section of the element, generating transverse and longitudinal stresses that cannot be neglected. In view of this, the main objective of this research is to carry out a parametric study on the Influence of curvatures and the insertion of support transversal (diaphragm) in bridges with curved longitudinal trajectory in the horizontal plane, in the distribution of bending moment in the spars. Thus, for the analysis of the behavior of bridges, numerical models using the Finite Element Method (FEM) using the software CsiBridge v20 will be used, as well as validated by the V-Load analytical method. The analysis of the results showed that the inclusion of the support transversal (diaphragm) made the bending moment distribution more balanced for most of the analyzed models. The curvature effect significantly altered the distribution of the BMDF in the beams along the cross section of curved bridges, showing a trend of progression of these factors as it approaches the girder most external to the curve. Such behavior is attributed to the coupled effects of the bending moment and torsion moment in the curved girders. In addition, the curvature induces a complex state of tensions, since these structures are subjected to twist combined with bending and shearing. In addition, regarding the influence of the TI's associated to the effect of the monolithic systems, there is a tendency of equivalence in the load distribution of the bridges as the quantity of TIs is increased for both precast and in situ molded construction methods. Finally, with respect to the V-Load Method, although it has been used in the past for open-section curved bridges, results of very discrepant bending moment distribution are presented when compared with the MEF results.