Parâmetro de instabilidade global gama-z: uma revisão sistemática da literatura

Abstract

Old buildings were characterized by rigid structures, composed of numerous large pillars and beams. In contrast, contemporary buildings have become taller, more slender, and based on lighter structural systems, making them more susceptible to instability. In this scenario, the analysis of global stability becomes essential to ensure that the structure can withstand vertical and horizontal loads without excessive deformation. Given these transformations, structural design has come to require more advanced and rigorous methods. NBR 6118 (ABNT, 2023) introduces the parameter γz as a tool to verify global stability in reinforced concrete structures. Thus, this work aims to conduct a systematic literature review on this coefficient. To this end, data were collected from the Scopus, SciELO, CAPES Journals, and Web of Science platforms, and the organization of the 33 selected publications was carried out using the Parsifal tool, of which 11 met the inclusion criteria. The results show that recent scientific production focuses on evaluating the applicability and reliability of γz and proposing new simplified analogous parameters, such as those based on the Galerkin Method, indicating that the normative coefficient performs satisfactorily in regular buildings, but tends to underestimate stresses in limit situations or with relevant torsional effects. It was also observed that only one study considers the most recent version of NBR 6118 and that all the identified research was developed by Brazilian authors. This research contributes to systematizing and critically organizing the literature on the γz coefficient, gathering recent evidence on its applicability and limitations, as well as identifying relevant gaps (especially the low incidence of studies using the most recent version of NBR 6118).