Deformation Capacity and Performance-Based Seismic Design for Reinforced Concrete Coupling Beams

Abstract

Reinforced concrete (RC) coupling beams are essential structural elements for their ability to reduce the bending moment of coupled walls as well as their capacity to dissipate energy. Deformation capacity of RC coupling beams is influenced by the relative depth coefficient of compression zone, the span-depth ratio, and the concrete confinement. In this paper, the relationship of the relative depth coefficient of compression zone ξ, the span-depth ratio χ, the confining reinforcement characteristic value λνb, and the ultimate plastic hinge rotation θuplb is established firstly. Then, the λνb - ξξ- χ - θuplb relationship is verified by the 48 RC coupling beam experiments conducted by 8 research institutions. Based on the relationship, the performance-based seismic design (PBSD) method for RC coupling beams is proposed. According to the method, the transverse reinforcement can be assessed if the plastic hinge rotation θ and the damage index Db are predetermined, which forms an important part of the PBSD method for RC coupling beams.