Seismic Retrofitting Using a Buckling-Restrained Brace with a Self-Joint Device

Abstract

In response to insufficient seismic capacity of older reinforced concrete (RC) buildings, wet-type retrofitting methods have been proven effective in significantly enhancing seismic capacity. However, the complexity of construction and execution challenges have made these methods difficult to apply to private buildings. This research proposed a dry-type method that employs a buckling-restrained-brace (BRB) with a self-joint device to address these challenges, wherein the BRBs can serve as dampers to absorb earthquake energy. Through comprehensive estimations of strength capacity of connected RC members and the design guidelines proposed in this study, cost-effective retrofitting and damage control can be achieved while preventing unexpected damages caused by the BRBs. Furthermore, the proposed dry-type retrofitting method does not require postinstallation anchors on RC frames due to incorporation of the self-joint device, which offers flexibility in space rearrangement and indicates the damage levels of the BRBs. Additionally, the concepts and proposed design guideline have been validated against a retrofitted frame specimen, demonstrating the retrofitting effectiveness compared to an un-retrofitted frame specimen.