Seismic-resistant self-centering rocking core system

• A self-centering rocking core (SC-RC) system was presented.
• Rigid-body rocking about the base of the frame increases the drift capacity of the SC-RC prior to brace member yielding/buckling.
• Friction bearings at the floor levels of the SC-RC dissipate energy during seismic response.
• Static and dynamic nonlinear analyses were performed on several SC-RC configurations.
• Preliminary results indicate that the SC-RC can perform as intended under earthquake excitation.

Conventional braced frame systems exhibit limited drift capacity before brace buckling and associated damage leads to strength and stiffness degradation. A self-centering rocking core (SC-RC) system is being developed to provide significant drift capacity while limiting damage and residual drift.The SC-RC system consists of beams, columns, and braces branching off a central column. Friction at lateral-load bearings that transfer inertia forces from the floor diaphragms to the SC-RC is used to dissipate energy to reduce the overall seismic response of the SC-RC system. Vertically oriented post-tensioning bars provide additional overturning moment resistance and help to reduce residual drift.The paper introduces a preliminary design approach for SC-RC systems. Several SC-RC systems are designed, and pushover and dynamic nonlinear analysis results are presented. Dynamic analysis results confirm the expected drift capacity and behavior of the system.