Proposed test program for evaluating the progressive collapse capacity of steel framed composite buildings

The threat of progressive collapse has been an increased concern for structural engineers in recent history. Current practice when designing structures to resist progressive collapse has focused on local strengthening of members and connections, and the addition of extra structural elements to “tie” the structure together. However, typical structures have a degree of inherent robustness that is not currently counted on by designers, which may lessen the need for these additional elements. Many of these elements that add integrity to the structure have not seen extensive experimental testing, and their strength and ductility are not fully understood. In an effort to fill this gap, a test program was designed and implemented to study the response of steel-framed composite buildings to the loss of a column. A prototype building was designed by Walter P. Moore to be consistent with current construction standards and practices. A test building was designed based on this prototype building, with spans and members scaled down slightly to accommodate the test frame. Test specimens consisted of a 2-bay by 2-bay section of the test building (in the case of an interior column loss) or a 2-bay by 1-bay section of the test building (in the case of a perimeter column loss). The effect of the surrounding building was simulated by the construction of a heavy restraining beam that circumscribed the test specimen, providing the restraint that would be present due to neighboring bays. A loading system and test protocol were designed to allow a uniform floor load to be applied to the test specimen while the column support is removed quasi-statically, with the potential for further uniform floor load to be added if the specimen survived column loss.