# CONSIDERATIONS ABOUT APPROXIMATE AND RIGOROUS METHODS FOR ANALYSIS OF REINFORCED CONCRETE BRIDGE DECK

## Palavras-chave:

Structural Analysis, Bridge, simplified models, reinforced concrete## Resumo

This paper presents an evaluation of the approximated methods for the calculation of

reinforced concrete bridge deck, considering the available numerical resources. In the past, it was

common to use simplifications in the calculation of the constituent elements of the bridge: the

superstructure and substructure, on the definition of the internal forces on the ultimate limit state

(ULS) and the displacements on the serviceability limit state (SLS). From this trivial analysis, usually

analytical, the verification of the parameters of the structure was made. It is known, however, that the

simplified structural analysis causes eventual inaccuracy on the internal forces and deflection values of

the bridges and viaducts, since it is not considered the real interaction, three-dimensional, between the

main constituent elements of the structure: bridge deck, girders, columns, abutments, wing walls and

foundation elements. Thus, an oversizing of the inputs is done, for example, consumption of steel and

concrete, thus, burdening the project in question. Considering the above, it was intended in this

research to make a comparison of the results obtained analytically in a reinforced concrete slab bridge

with the results using the tables of Rusch [1] taking into account the moving loads based on Brazilian

Technical Standards NBR 7188 [2] and NBR 7187 [3]. The analyzed bridge has two spans and total

lenght of 23.10 m, with central reinforced concrete pier. The abutments are closed and have, each one,

two wing walls, simultaneously acting as containment element and columns. For the analysis of the

bridge moving load, was considered the standard Brazilian vehicle class TB-450. Finally, after a

systematical analysis of results obtained from the analytical and numerical models of the bridge, some

considerations are made, especially regarding the use of simplified methods of structural analysis and

design.