PROGRESSIVE COLLAPSE OF MOMENT RESISTING STEEL FRAMES

Abstract

Progressive collapse due to losing one or more of the primary members is an essential factor which affects buildings stability. In this investigation, a steel structure model for an existing building is performed and verified by comparing analytical results with the experimental demolition results. It was simulated by removing four selected columns by linear analysis using a finite element program, with loads and factors according to the General Service Administration (GSA 2003). A parametric study was conducted on another steel frame to investigate the loss of three columns. The analyses done using the linear static and nonlinear dynamic. These models introduced slab diaphragm and horizontal belt truss to study their effect on decreasing the potential of progressive collapse. The slab diaphragm did not affect the results of the linear static analysis; however, it had a significant effect on the nonlinear dynamic analysis. The result of adding belt truss on the linear static model decreased DCR results by 50% and decreased the vertical displacement by 60 %. The effect of changing the damping ratio in the nonlinear dynamic analysis was studied, and it was found that it affects the displacement only in the first few seconds. However, it has a negligible effect on the final displacement.