Evaluation of an Existing Steel Frame Building against Progressive Collapse

The internal forces increase in structural components neighbouring a member, usually a column, removed or destroyed as a result of manmade or natural hazards, such as an explosion. If the additional internal forces created by an initial small or local structural failure can not be efficiently redistributed within the structure, damage spreads and partial or total collapse (progressive collapse) of the building occurs. Progressive collapse has been of an increasing concern in the structural engineering community, especially since the collapse of the World Trade Center towers in 2001. The terrorist attacks showed that well-designed and robust modern buildings can be susceptible to progressive collapse. The Ronan Point collapse of 1968 in London, and the bombing of the Alfred P. Murrah building in Oklahoma City in 1996 are the most publicized examples of progressive collapse [1]. Therefore, it is necessary to design of buildings to resist progressive collapse. In this study, progressive collapse performance of an actual building was investigated. The Ohio Student Union building, located on the Ohio State University campus, was also tested by physically removing four first story columns from one of the long perimeter frames prior to building's scheduled demolition. Our field experiments and analytical studies provide both practical and fundamental information on the collapse response of an existing building with a regular structural configuration. A commercially available computer program, SAP2000 was used to model and analyze the building following the General Services Administration (GSA, 2003) guidelines. The elastic static and nonlinear dynamic analysis results are presented and their implications are discussed.