Progressive collapse analysis of a steel building with pre‐northridge moment connections

Abstract

This study is on progressive collapse analysis of a sample steel building using various procedures suggested by the General Service Administration and the Department of Defense. The progressive collapse was accommodated by removing columns as per above guidelines. The analysis methods considered were linear static, linear dynamic, non-linear static and nonlinear dynamic using SAP2000 structural simulation program. The analysis model was a 3D nine-storey steel moment resisting building. For linear analysis, rigid moment connections were used, while for nonlinear analysis pre-Northridge connections were used. The effect of an extreme event was incorporated by removing a column in the analysis model. The static analysis was performed on the model with a column removed subjected to static gravity loadings. The dynamic analysis employed a ramp function to simulate the dynamic effect of the removal of a column. For nonlinear analysis, material nonlinearity was incorporated using strength degrading nonlinear hinges of pre-Northridge connections as per FEMA 356. The paper documents the results of this analysis with comparison among methods. The potential for collapse and performance levels of the building were determined using the demand capacity ratio and the rotational limit obtained through the analysis. Figure 8. Defl ected shape of the frame and displacement history (cm) of Node 461 after Column 2796 was removed. Nonlinear static analysis procedureA load combination of 1.2DL + 0.5LL was applied to the structure, except that to bays adjacent to the removed columns a load combination of 2.4DL + LL was applied (per DoD). The beam-column connections were modelled using the strength degrading moment-rotation relationship as shown in Figure 9 per FEMA 356 (FEMA, 2000) for pre-Northridge Welded Unreinforced Flanges (WUF) connections.At fi rst, only one column was removed at a time per DoD guidelines similarly to linear analyses. However, there were no plastic hinges formed at the beam-column joints. To further study nonlinear responses of the structure, two columns were removed simultaneously, signifying an event even M θ θ y Mψ Figure 9. Force-deformation curve in FEMA 356.470

A BIM-Based Preliminary Database Framework for Structural Hazard Prevention Analysis

“…Researchers have paid more attention to these sudden disasters in recent years, and meanwhile, some related papers have been published. For example, Purasinghe et al analyzed the progressive collapse of a sample steel building using various procedures [24]. Luccioni et al studied the structural failure process of a reinforced concrete building caused by a blast load [25].…”

Robustness assessment of planar steel frames caused by failure of a side column under localized fire

“…The research on progressive collapse of building structures could be traced to the incident that gas explosion caused partial collapse of a 22‐storey apartment building at Ronan Point in UK in 1968 . During the past several decades, a lot of research has been conducted on progressive collapse of building structures, and several guidelines have been developed to assess the progressive collapse resistance of building structures under explosion or impact loading. In these robustness assessment methods, the initial damage is considered to occur instantaneously with significant dynamic effects, which is normally the case for structures under explosion or impact loading.…”