Safe Seismic Design of Intermediate Precast Shear Wall System

ACI 318-19 and ASCE 7-22 specify code-compliant and emulative seismic force-resisting systems (SFRS) including intermediate precast shear wall systems. For the seismic design of a precast shear wall system, its successful performance heavily depends on the capacity design of inevitable discrete connections between precast wall panels, thus playing a critical role in controlling yielding to occur within steel reinforcements at the vicinity of intended locations or components. This is imperative for achieving not only ductility but also adequate energy dissipation, ensuring the system can effectively withstand seismic forces. To this end, the overstrength is essentially required to prevent any brittle failure, and the connections designed not to yield can be protected by addressing the 1.5Sy condition as specified in ACI 318-19 and ASCE 7-22. However, there can be a blind spot for the precast connections designed to yield. To this end, this study showed some cases based on practical examples from which a reasonable magnitude of overstrength (Sy) was tentatively recommended for better safety in the seismic design of the intermediate precast shear wall system with precast connections designed to be yielded.