Influence of Panel Zone on Progressive Collapse Resistance of Steel Structures

Abstract

This paper focuses on panel zone effects on the progressive collapse resistance of steel frames. A corner or middle column of the structure was immediately removed from the model according to General Services Administration (GSA) guidelines, and the progressive collapse of the frames was evaluated by nonlinear dynamic analysis. Two types of structural systems were designed for the building: (1) special moment frames in both directions, with box-section columns; and (2) special moment frames in one direction and special concentrically braced frames in another direction, with I-section columns. First, the panel zone model was verified by an experimental result, showing excellent correlation with the experiment. Then it was applied in the structures. The results show that considering panel zone in the structure with I-section columns intensify the progressive collapse, especially when removing a corner column. However, this influence is not considerable for the structure with box-section columns. Therefore, in general, the panel zone effect must be considered for progressive collapse. If shear resistance of panel zone just satisfies minimum criteria presented in building codes, its deformation should be considered in progressive collapse resistance of structures, and using center-to-centerline dimensions is not safe.