Application of strut-and-tie model in overhanging beams using CAST program

Resumo

The strut-and-tie model has been useful to solve problems involving D-regions (holes, dapped end
beam) in reinforced concrete. On this approach, overhanging beams supported by pile foundation has been found
frequently in building on the limit of land although its study does not follow the same intensity. This work aims to
compare the performance of some struts and tie topology for a beam under predefined load through CAST based
on Brazil Codes. The tool allows users an iterative process verifying each truss element. Nevertheless, there isn’t
automatic optimum topology generation thus requiring an experience by the designer to choose the best model. It
was proposed six varied layouts for a beam with constant geometric and materials properties, applying equal failure
load to all models. Reduced the load in order to obtain in stress ratio bellow and near to 1.0 in each model. The
results are presented comparing their reinforcement and limitations of layout. Some models reached equal
maximum load working different members. From the results, it was possible to define the beam with reasonable
performance and their applicability in practical design. It was discussed the potentials of the program like teaching
the strut-and-tie model and also automation in node verification.