Influência da geometria do núcleo rígido na sua eficiência como estrutura de contraventamento

Abstract

The use of rigid cores in slender multi-storey buildings, executed in reinforced concrete, is a very usual solution when there is a need to apply artifices to provide the structure global stability. This work evaluated the influence exerted on this bracing-system efficiency, due to its use with different geometries. Therefore, the structure of a 23-story building was dimensioned, in 4 different situations, where only the geometry of its rigid core was varied between the models in C, E, F and T. The purpose of this process was to verify how relevant this attribute is to the structure global stability, and whether this is a factor to be taken into consideration during its design. After carrying out the pre-dimensioning procedures of the elements that make up the structure, the software named Eberick was used to carry out its analysis and structural calculation. Then it was proposed, according to the methodology, the evaluation of some comparison parameters between the models. The observed lateral displacements, the coefficient γz values, indicated by the standard, and the forces acting on the foundation elements were verified. These results were also correlated with an estimate of consumption of inputs, steel and concrete. Based on the concepts verified in the literature review, it was possible to point out a variation in the parameters evaluated between the study models considered. It was observed that at the same time that the stiffening of the structure favors its global stability, it can lead to a greater consumption of materials, leading to the need for an evaluation that involves some factors to determine this characteristic of the rigid core. For the architectural model adopted, it was even possible to determine one of the geometries in which the structural stability met the economic advantage in relation to the estimation of the quantity of materials.