عنوان مقاله [English]
Progressive collapse first attracted the attention of engineers from the structural failure of a 22-story apartment building at Ronan-Point, London, UK, in 1968. The terminology of progressive collapse is defined as the spread of an initial local failure from element to element, eventually resulting in the collapse of an entire structure or a disproportionately large part of it. Any weakness in design or construction of structural elements can induce progressive collapse in structures during seismic loading. The modeling of building responses to progressive collapse has interested more and more researchers during the past two decades. The aim of this study is to investigate the seismic performance of special steel buildings including, moment resisting frames, moment resisting with concentrically braced frames and moment resisting with eccentrically braced frames, designed based on seismic codes with damaged members, and their ability to resist progressive collapse under earthquake loading. For this purpose, nonlinear dynamic analysis on 3-D structures using PERFORM 3D software was carried out, and seismic performance with a progressive collapse potential of 5 and 15 story buildings with 4 bays, applying an alternate load path method proposed on GSA2003 and UFC2009, was assessed. In this paper, plastic hinge generation in elements, story drift and the performance level of frames for various locations of column removal and lateral force resisting systems are investigated. Considering the response of the structures, it can be observed that the seismic behavior of structures basically depends on the location of the eliminated column and the type of lateral load resisting system, indicating the advantage of special moment resisting frames equipped with eccentric bracings. The reported results give better insight into understanding the effect of the type of lateral load resisting system on the dynamic response and seismic safety of special steel frames under progressive collapse. The results also state that when local damage occurs in the lower stories of steel frames designed according to special seismic requirements, no potential for progressive collapse exists.