Fuse replacement implementation by shaking table tests on hybrid moment-resisting frame

Abstract

A seismic resilience enhanced structural system, called Hybrid Moment-Resisting Frame with Replaceable Energy Dissipation Angles (HMRF-REDA), is proposed with the advantage of cost-effective and easy replacement work. The system consists of energy dissipation bays (EDBs) featuring fuse connections and re-centering bays (RBs) constructed from high strength steel (HSS). The fuse connections are designed to concentrate damage on sacrificial and easy-to-repair elements in the presence of a concrete slab. The HSS members not only provide adequate load carrying capacity but also necessary re-centering capability essential for fuse replacement. In this research, shaking table tests were performed to investigate the seismic performance of HMRF systems and in particular, the feasibility of on-site fuse replacement within the complete structural system. The specimen was comprised of two parallel, three-story hybrid moment-resisting frames at a 1/2 scale. The results demonstrated that HMRF-REDA exhibited a multi-stage yielding sequence with damage restricted to the fuse elements for the expected deformation range. The HSS frame members were able to fully re-center the structure after it underwent an inner-story drift of up to 0.0235 rad. Furthermore, two on-site fuse replacement operations were successfully implemented within the structural systems, demonstrating the feasibility and ease of operation. The frames with replaced fuses exhibited similar elastic and inelastic performance when it experienced a preceding drift up to 0.0184 rad.