Keywords: progressive collapse, moment resisting frames, linear analysis, braced frames.

Progressive collapse is the series of failures of load-carrying elements in the building caused by a local failure. The behavior of reinforced concrete buildings under the failure of such elements due to progressive collapse caused by abnormal loads and the techniques used for resisting this situation has been the subject of several studies. In this paper, the behavior of the reinforced concrete structure under the failure of edge column and how this issue can be withstood are studied and modeled using linear static analyses which are parts of the alternate path (A.P.) procedure, taking into consideration the guidance of the General Services Administration (GSA). An edge column loss in a 6- story building consisting of 5 bays on each side is modeled using the ETABS program. Multiple models are discussed to minimize the effect of the progressive collapse, including the addition of different types of steel bracing to identify the best model that reduces stresses generated due to the failure of an edge column. From the linear static model, it was found that removing an edge column will increase the moment and shear values in columns and beams, especially for those located on the exterior side of the building, so the amount of steel provided for them will also increase. Also, it is found that adding braces in the linear static model will reduce the moment and shear values in beams and columns, which will produce a more economical design. In the nonlinear static model, adding braces decreases the vertical displacement and rotation values significantly by about 75%, which will also produce a more economical design considering that the performance level reached was the Immediate Occupancy (IO) performance level.

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