Economic design issues of RC structures against progressive collapse

Abstract

Progressive collapse of structures is defined as the damage incurred on the structure as a result of abnormal and occasional loads which result in initiation of a chain reaction mechanism ending with progressive and disastrous failure. In this study, the economic cost of designing RC structures located in non-earthquake hazardous regions to meeting progressive collapse design requirements is estimated. Therefore, a typical reinforced concrete has been modeled to achieve the above objective. The Occupancy Category II per UFC 3-301-01 has been chosen for this structure. Tie Forces for the whole structure and Enhanced Local Resistance for the corner and penultimate columns at the first story are the design requirements for this OC. It was concluded that the cost of reinforcement for this OC level in order to meet UFC criteria and maintain safety requirements was around 15% compared to reinforcement requirements of ACI 318-08/IBC 2009 for non-seismic region. The importance of progressive collapse as a major concern has led to addition of explicit requirements regarding the redundancy of the structures in seismic codes throughout the world. Specific codes related to progressive collapse analysis of structures have been published by the Department of Defense (UFC 4-23-03) and the General Services Administration (GSA 2003). Most of the countries located in non-seismic regions are not designed properly against earthquakes according to the relevant seismic codes. Hence, the majority of typical RC buildings are exposed to progressive collapse in such regions. © Maxwell Scientific Organization, 2014.