Reinforced Concrete Core Wall Buildings with Modified Friction-Based Force-Limiting Connections: Connection Design Considerations and 3D Response to Bidirectional Ground Motions

This paper discusses the seismic response of a three-dimensional (3D) 18-story reinforced concrete core wall building model with modified friction-based force-limiting connections (Modified FDs) between the floors and reinforced concrete core wall. One set of design parameters that define the predetermined discrete variable friction force-displacement response of the Modified FDs was determined using Pareto front analysis. The Pareto front analysis utilized results from systematic parametric numerical earthquake simulations of two-dimensional (2D) building models and results from a practical force-based design method for force-limiting connections. A 3D model of an 18-story reinforced concrete core wall building was developed with experimentally calibrated wall piers and the Modified FDs considering the determined set of design parameters. Thirteen design-level far-field bidirectional ground motions were considered as seismic excitations. The use of the Modified FDs demonstrates a reduction in the peak torsional moment and base strain responses in the wall piers. A statistical analysis indicates a reasonable range of relative displacement between the floors and the wall piers. The use of the Modified FDs does not increase the expected postearthquake residual drift responses in the building system. The peak floor acceleration and base shear responses are limited, attributed to the controlled inelastic shear-dominant higher-mode responses enabled by the Modified FDs.