Análise numérica comparativa entre pontes integrais e convencionais de concreto armado sujeitas às ações indiretas de temperatura, retração e fluência
This research presents a comparative study between the structural behavior of reinforced concrete integral bridges and a conventional bridge, in order to analyze the variation of forces and displacements generated in the structure due to indirect actions such as creep, shrinkage and temperature v...
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| Formato: | Dissertação |
| Idioma: | pt_BR |
| Publicado em: |
Brasil
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| Endereço do item: | https://repositorio.ufrn.br/jspui/handle/123456789/28288 |
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| Resumo: | This research presents a comparative study between the structural behavior of
reinforced concrete integral bridges and a conventional bridge, in order to analyze the
variation of forces and displacements generated in the structure due to indirect actions
such as creep, shrinkage and temperature variation. To do this, the soil deformability
through soil-structure interaction (ISE) was considered using p-y curves where the
neighboring soil is represented by a set of horizontal springs with nonlinear behavior. In
addition, a three-dimensional numerical analysis of three-span bridges was performed
using a software based on Finite Element Method (FEM), analyzing 03 (three) different
structural systems: (a) integral bridge; (b) integral abutment bridge and (c) conventional
bridge, the latter consisting of isostatic spans separated by expansion joints. Finally, a
comparison was made between the results obtained with the integral bridges systems
and the conventional bridge and a comparison of the results obtained from the FEM with
analytical models, using NBR 6118 (2014), NBR 7187 (2003) and NBR 7187 (1987) to
check temperature action and the Eurocode 2 (2004) model for creep and shrinkage.
The shrinkage and creep actions were analyzed separately from the thermal actions.
The results showed that the thermal gradient action resulted in significant negative
bending moments in the bridge end regions, especially in the abutment region, where
the moment presented its maximum absolute value. Regarding the creep and shrinkage
effects, for both types of integral systems studied, it was found that these actions caused
unfavorable effects in the bridge end span generating the addition of significant bending
moments, with maximum percentage variation of 9.3%. In the abutment section, this
effect was favorable, resulting in a reduction in the absolute value of bending moment,
with a maximum percentage variation of 22.8%. However, although favorable, a greater
influence of rheological effects on the ends of integral bridges was noticed. Finally, by
analyzing the displacements in the end span of each model, it was possible to verify that the amplification factor of the deformations was always higher for the integrals bridges
models, showing that in this structural system, the effects of creep and shrinkage are
more significant and should be taken into account in the design. |
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