Towards Implementation of Controlled Rocking Braced Frames as a Standardized Lateral Force Resisting System in Canada

Most modern earthquake engineering relies on inelastic behaviour within the lateral force resisting system to dissipate energy while preventing collapse. These modern codes and standards have significantly reduced fatalities during major earthquakes, yet this approach often leaves buildings with permanent damage and residual drifts that require extensive repair or even demolition. Controlled rocking braced frames (CRBFs) have emerged as an innovative lateral force resisting system that minimizes damage and residual drifts by allowing selected columns to uplift. During an earthquake, CRBFs utilize their self-weight to restore the structure to equilibrium. Energy dissipation mechanisms may also be added to control the overall response. While previous research has provided a framework for the design of CRBFs, their widespread adoption in Canada is hindered by the absence of comprehensive national guidance and design office-level resources and examples. This paper seeks to address this gap by demonstrating how a proposed design process would apply to a range of archetype buildings in Canadian regions with varying levels of seismicity, and then evaluating their performance through non-linear response history analysis. The archetypes, with different occupancies, configurations, and heights, provide a broad overview of the possible applications of CRBF structures nationwide. The non-linear dynamic analysis incorporates ground motions scaled to site-specific seismic design spectra to represent the risk at each location. After examining the design practicality and seismic performance of the archetype structures across the design space, recommendations are made to address potentially restrictive research gaps and to indicate CRBF archetypes ideal for development. The analysis results contribute insights into the practical implementation and design of optimal CRBFs that would enhance seismic resilience in Canadian steel building design.