EFFECT OF THE JOINT STRENGTH ON THE PERFORMANCE OF ORDINARY MOMENT-RESISTING FRAMES UNDER A PROGRESSIVE COLLAPSE SITUATION

摘要

In standard design procedures of steel structures, buildings are usually designed for gravity and seismic load rather than a progressive collapse situation. When a structure is located in a low seismic zone, the codes have dictated fewer requirements regarding the beam-to-column strength ratio and the panelzone strength. In this study, a frame subassembly from an 8-story ordinary steel moment-resisting structure with different strength of exterior joints was investigated by numerical models under a column removal situation. The results revealed that although the beam-to-column strength ratio and the panelzone strength are generally less critical parameters in the seismic design of ordinary moment-resisting frames, they can have a notable effect on the fracture pattern and the capacity of the structure under a progressive collapse. Hence a special consideration about the joints strength is needed when a structure is aimed to be designed for a progressive collapse situation.