The Oklahoma City Bombing: Summary and Recommendations for Multihazard Mitigation

From visual inspection and analysis of the damage that occurred in the Murrah Building as a result of a blast caused by a large truck bomb, it is shown that progressive collapse extended the damage beyond that caused directly by the blast. The type of damage that occurred and the resulting collapse of nearly half the building is consistent with what would be expected for an ordinary moment frame building of the type and detailing available in the mid-1970s when subjected to the blast from such a large truck bomb. Using information developed for the Federal Emergency Management Agency and the Department of Housing and Urban Development, types of structural systems that would provide significant increases in toughness to structures subjected to catastrophic loading from events such as major earthquakes and blasts are identified. One of these systems is compartmentalized construction, in which a large percentage of the building has structural walls that are reinforced to provide structural integrity in case the building is damaged. Two additional types of detailing, used in areas of high seismicity, are special moment frame construction and dual systems with special moment frames (herein referred to as dual systems). This paper shows that compartmentalized construction, special moment frames, and dual systems provide the mass and toughness necessary to reduce the effects of extreme overloads on buildings. Consequently, it is recommended that these structural systems be considered where a significant risk of seismic and/or blast damage exists.