Estudo de punção em lajes - modelos teóricos e análise em códigos computacionais

Abstract

The structural system composed of slabs directly supported by the columns, without beams for straining transfers, named flat slabs, is a very widespread and well accepted system by the technical community due to the various advantages over the conventional system of slabs supported by beams, especially in situations of architecturally differentiated projects. The objective of this study was to analyze the differences obtained with the use of the Brazilian, American and European codes for designs of reinforced concrete structures in the punching shear verifications of the mostly common cases of the practice of structural projects, and also make a comparative analysis of the results obtained through the national softwares most used by the technical community for this type of project, the AltoQI Eberick and the CAD/TQS, with those obtained by the Brazilian code, in order to verify and explain the cause of possible differences in the results. To obtain the necessary data, 168 punching shear verifications were performed in 21 different configurations of slabs, and also 35 computational analysis to verify the software results. The results showed a wide variation in values obtained for each standard for each different configuration of slab, which was attributed to different factors and limitations considered by each of the models used in the formulations, so there is no way to classify each model as more or less conservative. Concerning to the softwares, it was realized that the AltoQI Eberick results in values equal to those obtained through the Brazilian standard, while the CAD/TQS, due to its different calculation method, results in different values instead of the recommended by this code.