Rapid Seismic Rehabilitation Strategy: Concept and Testing of Cable Bracing with Couples Resisting Damper

Abstract

The goal of this study is to design and evaluate simple and rapid seismic retrofit devices for relatively small rehabilitation projects for steel structures. These designs are consistent with the tenets of sustainable design and will result in a more resilient building stock as well as minimizing environmental and economical effects and social consequences during the rehabilitation project. To achieve these goals, a unique approach to designing supplemental systems by using tension-only elements is proposed, one that eliminates undesirable global and local buckling. The first generation of these devices, a bracing system consisting of cables and a central energy dissipating device [couples resisting (CORE) damper], is presented in this paper. Both analytical studies with advanced and simplified models and proof-of-concept testing demonstrated stable, highly efficient performance of the system under seismic loads. Preliminary applications of the CORE damper system to the retrofitting of a braced steel frame showed the ability of the system to minimize soft story failures and residual deformations.