Impacto das propostas de alteração do mapa de ventos no projeto de edifícios em concreto armado no Brasil

Abstract

The wind action is one of the most relevant for the design of reinforced concrete buildings, especially in recent years with the growing demand for taller and slender buildings. Thus, it is essential that this action be determined accurately and in accordance with reality, to ensure both the safety of the building and its occupants as well as the economic feasibility of the project. In Brazil, the process of determining the wind action is established by ABNT NBR 6123 (1988), considering that it is already 34 years old and is based on a study of isoplet maps of Brazil of almost 50 years, it is currently under revision. Therefore, the objective of this work is to evaluate the impact that the proposed isoplet maps presented as suggestions for the revision of the wind standard will have on the design of reinforced concrete structures in several regions of the country for buildings of various heights. Structures of 4, 10 and 20 floors were evaluated using the commercial software TQS, in 8 cities with different basic wind speeds, and both the Ultimate Limit State and the Service Limit State of the structure were studied. The results indicate that for 4-story buildings there is no impact on the design with the change of the wind speed, whereas for 10 and 20-story buildings the results point to a more significant impact. Furthermore, the analysis of the results and the isoplet maps proposals make clear the need for revision in ABNT NBR 6123 (1988).