Vertical geometric irregularity assessment of steel frames on robustness and disproportionate collapse: Fid-Bau Portal

Vertical geometric irregularity assessment of steel frames on robustness and disproportionate collapse

Gerasimidis, S. / Bisbos, C.D. / Baniotopoulos, C.C.

Abstract Disproportionate collapse of building structures can be defined as the partial or total failure of a building as a consequence of an initial local damaging event which develops throughout the structural system of the building. Various building structural systems depending on their level of available ductility and redundancy can perform better or worse to disproportionate collapse events; their resistance to the phenomenon is a function of many parameters including their regularity or not. This paper presents an extensive parametric study on the response of irregular steel frames in case of initial damage, expressed by the total removal of their columns, one in turn. The study regards a set of 15 steel frames designed according to the Eurocodes and the Greek codes. Morphologically, the frames include vertical geometric irregularity leading to useful conclusions regarding the influence of such a property in their resistance to disproportionate collapse. At the end of the paper, the results of the analyses are presented for their limit analysis, their elastic limit and their respective robustness measures. Special attention is given to the influence of vertical geometric irregularity through comparative results.

Highlights ► Disproportionate collapse of steel frames. ► Assessment of vertical geometric irregularity of steel frames. ► Robustness and disproportionate or progressive collapse. ► Proposed robustness measures.