TOWARDS CANADIAN DESIGN GUIDANCE FOR CONTROLLED ROCKING BRACED FRAMES: LOW-RISE BUILDING EXAMPLE

Modern earthquake engineering practice relies on the inelastic behaviour of select elements within the lateral force-resisting system to achieve seismic energy dissipation and prevent building collapse. These structures are therefore susceptible to permanent structural damage and residual drifts after design-level seismic events. Controlled rocking braced frames (CRBFs) have been shown to control seismic damage and limit residual displacement by allowing selected CRBF columns to intentionally uplift. Despite the promise of CRBFs, they are not included in any international design code, and New Zealand is currently the only country in the world that has a guide for practitioners looking to implement the recommendations from research. To address this gap, this paper will offer a step towards design guidance for CRBFs that are compliant with Canadian design codes and standards, namely CSA S16 and the National Building Code. First, a design methodology is presented with a performance target of matching or improving code-compliant buildings. The design steps are then implemented to design a representative low-rise building with CRBFs as the primary lateral force resisting system. Nonlinear response history analysis is performed using models of the archetype building during ground motions that are selected and scaled with reference to the design spectrum. The performance indicators determined from these analyses are compared to the design objectives to assess the effectiveness of the design procedure. While the design guidance presented in this paper is specifically formulated for a Canadian context, the research will be relevant to researchers and practitioners in other nations as they establish their code-compliant approaches to designing and constructing CRBFs for improved seismic resilience.