Análise comparativa de métodos de verificação de carregamento em OAE visando à emissão de autorização especial de trânsito

Abstract

Aiming to develop a comparative evaluation of the principles for the analysis of loads in bridges, this work proposes to carry out the structural verification of a Special Engineering Structure, through the study of the mobile loads adopted by the Brazilian regulations (NBR 7188:2013), American (AASHTO: 2002 and 2020) and European (Eurocode 1: 2003). The verification of the requested loads, generated through the mobile loads described in the respective norms, was carried out on the bridge of the Croatá river, located in BR-423/AL, municipality of Canapi/AL, observing the limits of weight and dimensions, related to cargo vehicles on Brazilian highways, established by the resolutions of the National Traffic Council – CONTRAN. The bridge design information was made available by DNIT/AL, enabling the evaluation of the requesting efforts generated by the project loads described in the aforementioned standards and by a special type of freight train. Numerical modeling was used through the finite element method - FEM, to analyze the effects of the passage of the type trains, determining the maximum requests generated in the superstructure with the passage of the type trains, comparing them and applying the determinations established in the regulations. Making use of the requesting efforts arising from the numerical analysis, the methodology established by the DNIT for the elaboration of concessions of Special Transit Authorizations was applied to the results obtained, which establishes the criteria for verifying structural safety in road bridges. Through this study, it was concluded that the special structure under discussion is in adequate structural conditions for the passage of special loads and loads of international standards, whose safety factors presented in the verifications are superior to unity. It was also concluded that the Brazilian regulations, in contrast to the international norms, presented in the analyzed case values of greater safety factors during the structural verification.