Vulnerability assessment of reinforced concrete structures for fire and earthquake risk

This chapter provides an overview on the performance and vulnerability of structures in fire and earthquake. Two main scenarios of fire and earthquake are explored: (1) when a structure is damaged first by an earthquake and then exposed to a fire (fire following an earthquake) and (2) when a structure is damaged by a fire and therefore its residual seismic capacity needs to be assessed and inspected. Three case studies are presented: one for the fire following an earthquake scenario and two case studies for the second scenario. A large-scale, six-storey reinforced concrete building, previously tested on a shaking table, was selected and numerically evaluated for the scenario of the fire following an earthquake. The results of the analysis show that damage to the structural elements, during an earthquake, could result in degradation of the concrete mechanical properties and could increase heat transfer to the structural elements and therefore lower its residual fire resistance. Two reinforced concrete columns tested previously in fire were chosen and numerically assessed for their residual seismic resistance. Furthermore, a reinforced concrete column was experimentally tested in a fire and then tested under both axial and lateral load to evaluate and inspect its residual lateral load capacity. The results from these two studies indicate that a fire could considerably reduce lateral and axial load capacity as well as ductility of the structures. Finally, some of the research gaps in this area are identified and future studies recommended.NRC publication: Ye