Estudo comparativo entre os comportamentos estruturais de escadas apoiadas e autoportantes em concreto armado

Abstract

The present work aims to carry out a comparative study between the analytical calculations of supported and free-standing stairs in reinforced concrete. To this end, the geometric aspects of the study stairs were determined, as well as the loads acting on them according to NBR 6120 (ABNT, 2019). Then, the internal stresses were obtained through analytical and numerical methods, using the Ftool Software (MARTHA, 2018) for the conventional stairs and the Araújo (2014) and Knijnik and Tavares (1977) methods for the free-standing stairs. The stairs’ displacements were also determined using the Ftool Software (MARTHA, 2018) for the conventional stairs and by the method of Araújo (2014) for the self-supporting stairs. In addition, the design of the structures was carried out according to NBR 6118 (ABNT, 2014) and then it was made a comparative analysis between the results of stresses, displacements and design of the structures, focusing on structural efficiency, considering the variables "slab thickness" and “landings” for supported stairs and “slab thickness” and “calculation method” for free-standing stairs. It was found that most of the analyzed samples showed an increase in the percentage variation of bending moments, as well as in the analysis of shear forces performed for a part of the samples. In terms of displacements and steel areas, there was a decrease for all samples.