Performance-Based Seismic Design of Controlled Rocking Steel Braced Frames. I: Methodological Framework and Design of Base Rocking Joint

Abstract

AbstractControlled rocking steel braced frames (CRSBFs) are being developed as a seismic force resisting system that can be constructed economically to avoid structural damage and residual deformations following an earthquake. In a CRSBF, selected columns are permitted to uplift from the foundation in response to severe seismic loading, and posttensioning and energy dissipation are selected to control the magnitude of the rocking response. Despite extensive experimental testing to demonstrate that this behavior is stable and repeatable, there has been a lack of comprehensive guidance for potential designers of CRSBFs. This paper proposes a performance-based design methodology for CRSBFs, which consists of defining the performance objectives, designing the base rocking joint based on a single-degree-of-freedom (SDOF) model, and capacity protecting the rest of the structure for the maximum forces expected during the rocking response. This paper focuses on the design of the base rocking joint, while Part II ...