A Performance-Based Design Approach for Coupled Core Wall Systems with Diagonally Reinforced Concrete Coupling Beams

Abstract

Coupled core wall systems (CCWs) are lateral force resisting systems that can provide remarkable lateral stiffness for mid- to high-rise buildings, exceeding the lateral stiffness of isolated walls while providing the redundancy and force redistribution capabilities of framed systems. The lateral stiffness provided by CCWs largely depends on the type of coupling beams used to transfer forces between wall piers. Diagonally-reinforced concrete coupling beams are one of the more common details although composite alternatives (e.g., those using structural steel W-shapes, hollow structural steel sections, or embedded steel plates) or beams with rhombic reinforcement are increasingly being selected as viable alternatives. Despite the favorable behavior exhibited by diagonally-reinforced coupling beams in experimental studies, designing and constructing diagonally-reinforced coupling beams having practical span-to-depth ratios presents significant difficulties, impacting the use of CCWs as a viable lateral force resisting system. This paper presents a performance-based design (PBD) approach that allows the designer to successfully proportion a code-compliant CCW system that addresses the shortcomings related to the traditional strength-based design approach. A prototype building is designed following both approaches, and is analyzed both statically and dynamically. Results show that the PBD approach produces a code-compliant structure that satisfies the most pressing constructability constraints.