Seismic design of self-centering rocking core-moment frames with extended displacement-based approach for higher modes

Abstract

This paper introduces a novel displacement-based design method specifically tailored for Rocking Core-Moment Frame (RCMF) archetypes. RCMFs integrate the self-centering capabilities of Rocking Cores (RCs) with the energy dissipation capacity of Repairable Moment Frames (RMFs). The proposed design procedure accurately estimates higher-mode demands, which are essential for the capacity design of RCMF members. It emphasizes predicting design forces, by appropriately allocating strength between RMFs and RCs using the cantilever beam analogy. Additionally, a fail-safe mechanism is introduced to the RCMF design, ensuring self-centering at the immediate occupancy level while preventing potential collapse at design level. To validate the proposed approach and analytical formulas, nonlinear dynamic analyses are conducted on RCMFs subjected to far-field ground motions. The procedure concludes with the seismic evaluation of illustrative archetypes, including buildings supported by pinned and stepping cores, with both single and coupled configurations. The outcomes demonstrate the efficiency of the proposed displacement-based design procedure for the rapid analysis and preliminary design of RCMFs.