Structural Collapse: Quarter-Scale Model Experiments

Abstract : Terrorist-bombing events throughout the world have demonstrated the vulnerability of conventional reinforced concrete buildings to blast effects. Typical columns and floor slab systems are not designed to resist the complex blast loading, such as uplift or reverse loading of floor slabs and the combined lateral and tensile loading of columns. Parameters that may affect the response of a column/slab system to blast loading include structural details and the presence of non structural components. Two story, quarter-scale models were used to investigate the blast response of a typical flat-plate system. Experiments were conducted on five models, allowing a variation in the explosives standoff and the cladding configuration. The experiments successfully demonstrated the response of reinforced concrete frame structures to blast effects. It was demonstrated that the presence of in-fill walls has a significant effect on the impulse of the load applied to a column. Additionally, light walls act as a shield that attenuates the blast pressure enough to significantly reduce the blast effects on the slab floors. A primary conclusion is that the slab edge beams carried the dead weight, particularly the added weight at the top of the column when the columns incurred severe damage. Otherwise, collapse would have occurred.