Performance evaluation of precast vertical wall connections featuring an innovative locking bar under cyclic loading

Abstract

The incorporation of precast structural wall connections is essential in the construction of buildings, serving to ensure structural stability against lateral forces. To assure the efficiency and permanent performance of these precast structural wall connections, it is imperative to observe appropriate design, detailing, and construction techniques. This study explores four distinct connection designs implemented between shear walls. This specific type of connections presents numerous benefits, such as an ability to bear heavy loads, ease of construction, and enhanced resistance to seismic activity. The purpose of this study is to assess vertical wall-to-wall connectors seismic performance for following four connection methods: (1) Staggered Loop bar with Shear Key (SL-SK), (2) U-bar Hook with Shear Key (UH-SK), (3) U-bar Hook with Locking bar (UH-LB), and (4) U-bar Hook with Shear Key and Locking bar (UH-SK-LB). The research conducted a comparative analysis of the mechanical characteristics, encompassing load bearing capacity, stiffness degradation, hysteretic response, ductility, viscous damping ratio, and energy dissipation for all four connection types. The results indicated that the (SL-SK) specimen demonstrated excellent ductile behavior, a higher ultimate load capacity, and improved energy dissipation performance. These attributes were influenced by the trapezoidal design of the shear key with a 45° tooth angle under cyclic loading conditions. With an average ductility factor exceeding 4, this specimen is recommended for use in high seismic regions.