Seismic Performance of a Large-Scale Steel Self-Centering Moment-Resisting Frame: MCE Hybrid Simulations and Quasi-Static Pushover Tests

AbstractThis paper presents an experimental study of a 0.6-scale 2-bay 4-story steel self-centering moment-resisting frame (SC-MRF) test structure under maximum considered earthquake (MCE) ground motions. A SC-MRF uses high-strength posttensioning (PT) strands to precompress the beams to the columns and to close the gaps between the beam flanges and column flanges that occur at the beam-column interface under earthquake loading, returning the frame to its initial position (i.e., the frame is self-centering). In this study, a beam web friction device is included in each beam-column connection to dissipate energy under seismic loading. The SC-MRF design objectives are to be without structural damage, creating the potential for immediate occupancy performance under the design basis earthquake, and to suffer only modest damage, leading to collapse prevention (CP) performance under the MCE. The CP performance is achieved by avoiding beam web buckling and PT strand yielding and fracture. A special fuse that prevents PT strands from yielding is described. Experimental results from MCE-level earthquake hybrid simulations and quasi-static pushover tests on the SC-MRF test structure are presented. The experimental results show that the SC-MRF did not collapse under the MCE, and that the fuse is a viable alternative to protect PT strands from yielding.