Large-Scale Experimental Results for Self-Centering Beams with Resilient Seismic Performance

Abstract

Although several self-centering seismic systems have been developed in the past, their implementation in practice has been relatively limited. Unusual field construction practices, perceived initial cost premiums and deformation incompatibility with the gravity framing are some of the issues that may be factors. A self centering beam moment frame (SCB-MF) has been developed that mitigates several of these issues. The self-centering beam (SCB) can be shop fabricated with a restoring force mechanism which eliminates deformation incompatibility and allows conventional field construction methods. The strength and stiffness of the beam are decoupled resulting in a cost-effective system that may be competitive with conventional moment frames. This paper describes an experimental program on two-thirds scale one-bay SCB specimens. Parameters that were varied in these tests include SCB depth, initial post-tensioning stress, ratio of initial post-tensioning force to fuse yield capacity, and nominal moment strength of the system. A detailed description of the test setup, post-tensioning procedure, and implementation of the energy dissipation fuse will be presented. Finally, the testing results including the behavior of the individual components (energy dissipation fuse, PT strands and beam) and global system behavior will be summarized.