Self-Centering Moment Connections for Damage-Free Seismic Response of Steel MRFs: Fid-Bau Portal

Self-Centering Moment Connections for Damage-Free Seismic Response of Steel MRFs

Ricles, J. M. / Sause, R. / Lin, Y. -C. / Seo, C. -Y.

A self-centering moment resisting frame (SC-MRF) is a viable alternative to a conventional MRF with welded beam-column connections for seismic resistant buildings. An SC-MRF is characterized by gap opening and closing at the beam-column interface under earthquake loading. The beams are post-tensioned to columns by high strength post-tensioning (PT) strands oriented horizontally to provide self-centering forces when gap opening occurs. For the SC-MRF investigated in this research, energy dissipation is provided by beam web friction devices (WFDs) attached to the columns at the beam-column interface. The SC-MRF in this study is designed to meet several seismic performance objectives. These include no damage under the Design Basis Earthquake (DBE), leading to immediate occupancy performance following the DBE. In addition, under the Maximum Considered Earthquake (MCE) the structure is designed to have minimal damage and achieve the collapse prevention performance level. A 7-bay, 4-story SC-MRF prototype building located on stiff soil in the Los Angeles area was designed with WFDs using a performance-based design procedure with the above performance objectives. A 0.6-scale model of two bays of the SC-MRF was developed and tested under simulated earthquake loading using the hybrid simulation method to include the remaining parts of the building in the simulation. This paper presents an overview of the moment connections in the SC-MRF, the performance-based design procedure, test results, and an assessment of the design procedure.