Experimental investigation of the progressive collapse of a steel post-tensioned energy dissipating frame

Experiments were performed to evaluate the progressive collapse resistance of steel buildings considering multi-hazard extreme loading. As part of the experimental program a 1/3 ^rd scale three-story, two-bay post-tensioned energy dissipating frame (PTED) designed and previously tested for seismic performance on a shaking table, was adapted for quasi static collapse testing. The experiment simulated the structural response of the building after the sudden failure of a base column. The scope of the test was to evaluate the effectiveness of earthquake resistant design details in the resistance to progressive collapse. An effort was made to document the sequence of damage in the frame and to correlate observed damage with changes in the resisting strength. The experimental results demonstrate significant vertical displacement capacity and the ability of the steel framing to redistribute loads after the failure of a single column. The vertical load carrying capacity of the post-tensioned energy dissipating frame depends primarily on the performance and ultimate strength of the tendons used for connecting the beams to the columns. The PTED frame lost a significant amount of strength after the first failure in one of the tendon strands. A numerical simulation investigates the possibility to reproduce the experimentally measured response with commercial structural analysis software.