Experimental Behavior and Performance Evaluation of a Large-Scale Composite MRF System under Seismic Loading

Abstract

The behavior and seismic performance of composite moment resisting frames (MRFs) comprised of concrete filled tubes (CFTs) and wide flange beams was experimentally investigated. A fourstory two-thirds scale composite MRF test structure was designed using performance-based design concepts. The performance objectives included operational conditions after subjecting the structure to a series of ground motions representing a frequent occurrence event (FOE), life safety after a design basis event (DBE), and collapse prevention when subjected to the maximum considered event (MCE). The hybrid pseudo-dynamic test method was used to subject the test structure to these various seismic hazard levels. P-∆ effects associated with the gravity frames in the prototype building were analytically considered during the tests. A displacement convergence loop was included in the testing algorithm in order to achieve stable response during the tests, where inelastic behavior and participation of higher modes occurred. Results from the tests indicated that the structural performance under the simulated seismic loading was consistent with the expected performance for all the hazard levels, indicating that effective seismic performance of composite MRFs with CFT columns can be achieved.