Comparação das versões 1997 e 2022 da NBR 7190 no dimensionamento de estruturas de madeira: estudo de caso da cobertura do auditório do CTU-UESPI

Abstract

Wood is one of the oldest materials used in civil construction, standing out for its combination of properties that make it highly competitive in contemporary structural applications. This study aims to perform a comparative analysis between the 1997 and 2022 versions of NBR 7190, the Brazilian standard that regulates the design of timber structures. The research was applied through a practical case study: the roof structure of the auditorium at the Center for Technology and Urbanism of the State University of Piauí (CTU–UESPI), originally designed in steel and adapted to wood for comparison purposes. The study focused on three main aspects: theoretical framework, technical design criteria, and economic evaluation. The theoretical analysis revealed significant changes in normative principles, such as new classification methods for timber, revisions to modification coefficients, and updates to stability and connection requirements. From a technical perspective, the standard changes directly affected the structural design, requiring different cross-sections in specific cases. Economically, it was observed that the 1997 version led to a more cost-effective design, as the 2022 version resulted in a 30,11% higher cost. This increase is attributed to the more stringent requirements of the current version, particularly regarding the design of compressed members. In contrast, the 2022 version adopted a more conservative approach, with a greater number of verifications and stricter design criteria, aligned with modern trends in structural safety and performance. Therefore, the normative updates reflect a technical evolution in the field, demanding greater precision and investment, while enhancing the reliability of timber structural designs.