Evaluation of different loading simulation approaches for progressive collapse analysis of regular building frames

Applications of different loading simulation approaches to progressive collapse analysis of building frames subjected to sudden column loss are evaluated in this paper. Analytical investigation on the nonlinear static behaviour of a middle-supported clamped beam reveals that both the load-release and direct loading techniques will result in consistent response if the supporting force may be completely released. However, the dynamic load-displacement responses of eight building models indicate that the direct loading approach may predict less load capacity and larger displacement demand than the load-release one. The relative error in load-displacement response is more significant with the pseudo-static estimation. The difference in displacement response between the load-release and the direct loading or pseudo-static approaches may increase with the extent of plastification and number of storeys of the building frames. An empirical formula is proposed and validated for estimating the displacement error. T...