Concrete compressive characteristic strength analysis of three-pile caps

Resumo

In this paper a numerical analysis of three-pile caps is developed to study the influence of concrete compressive characteristic strength in pile caps load bearing capacity. A three-pile cap model derived from Miguel’s [1] work was adopted. From this model, variations on the concrete compressive characteristic strength (fck) were made in order to observe modifications in pile cap’s structural behavior. The numerical analysis was developed with the finite element software ATENA 3D [2]. The results demonstrated that an increase in the concrete compressive characteristic strength was not followed by a significant increment in pile cap’s ultimate strength, since models’ collapse were due to concrete splitting (opening cracks parallel to principal compressive stresses as a result of perpendicular tension stresses within the structure) and ties steel bars yielding. In the models analyzed high-tension stresses were developed along the struts and at the bottom of the pile cap’s section, demonstrating that pile cap’s ultimate strength capacity is not influenced by the concrete compressive strength.