Diseño del sistema sismorresistente de una estructura utilizando pórticos con riostras de pandeo restringido (BRBFs)

Abstract

Braced Frames are structural systems used for the stabilization and displacement control of structures against lateral loads. In this system, braces resist compression and tension loads in order to help decrease frame distortion and laterally stiffen the structure.

However, this lateral stabilization is not uniform, because when the brace is resisting compression forces, it buckles due to its slenderness, considerably limiting its compression capacity and, consequently, its necessary ductility.

On the other hand, Steel Buckling-Restrained Braced Frames make up a seismic resistant system relatively new and innovative, which provides a better structural response due to buckling restriction through the implementation of mechanisms and frame structural requirements.

The present work proposes a structural design using Buckling-Restrained Braced Frames, complying with the requirements of maximum story drifts and element resistance.

Based on the concept of capacity design, braces were designed to resist lateral loads resulting from a design earthquake DBE. Later the rest of the structural elements were designed to resist expected forces produced by brace yielding. Additional requirements of yielding and frame distortion were checked in order to ensure ductility. Finally, an evaluation was carried on by submitting the structure to an acceleration record corresponding to a maximum considered earthquake MCE in order to determine its seismic performance. Results based on the complying of maximum story drift ratios and element resistance indicate that the structure meets a performance level that is acceptable for special use structures.