Análise comparativa com foco em estabilidade global em edifícios de multipavimentos em concreto armado utilizando modelos de cálculo IV e VI do software CAD/TQS

Abstract

The analysis of global stability in high-rise reinforced concrete buildings is sensitive to the modeling assumptions adopted, especially in systems that with beams. This work aims to perform a comparative analysis between calculation models IV (Decoupled Grid and Frame) and VI (Integrated Spatial Frame) of the CAD/TQS software, evaluating their impact on stability parameters (Gama-Z) and horizontal displacement. The methodology consisted numerical simulation of multi-story buildings, comparing two structural typologies: conventional system (beam-column-slab) and waffle flat slab system. The results showed that, conventional system, alternating between models generates marginal variations in stability coefficients due to the preponderance of beams in the frame locking. However, for the flat slab system, a critical divergence was observed: Model IV, based on the simple rigid diaphragm hypothesis, resulted in a Gama-Z coefficient of 1,60, diagnosing the structure as unstable. In contrast, Model VI, by integrating the slab's flexural stiffness into the global matrix, reduced the coefficient to 1,21 (a 24% reduction), technically validating the project. It is concluded that the adoption of integrated models is mandatory for the safe analysis of flat slab buildings, since neglecting the frame effect formed by the slab-column assembly can lead to erroneous instability diagnoses and unnecessary oversizing.