Vulnerability assessment of reinforced concrete structures for fire and earthquake risk - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 359

14
Vulnerability assessment of reinforced
concrete structures for fi re and
earthquake risk
H. MOSTAFAEI, National Research Council, Canada
DOI : 10.1533/9780857098986.3.366
Abstract : This chapter provides an overview on the performance and
vulnerability of structures in fi re and earthquake. Two main scenarios of
fi re and earthquake are explored: (1) when a structure is damaged fi rst
by an earthquake and then exposed to a fi re (fi re following an
earthquake) and (2) when a structure is damaged by a fi re and therefore
its residual seismic capacity needs to be assessed and inspected. Three
case studies are presented: one for the fi re 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 fi re
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
fi re resistance. Two reinforced concrete columns tested previously in
fi re were chosen and numerically assessed for their residual seismic
resistance. Furthermore, a reinforced concrete column was
experimentally tested in a fi re 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 fi re 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 identifi ed
and future studies recommended.
Key words : fi re and earthquake, concrete structures, fi re damage, seismic
damage, fi re test, residual lateral resistance.
14.1 Introduction
Various design codes, standards and guidelines for fi re or seismic design of
structures have been developed in different countries around the world to
ensure the safety of occupants in buildings in the event of a fi re or an
earthquake. Seismic design codes provide tools for design and recommen-
dations for analysis of structures against earthquake, while fi re design codes
provide requirements for the fi re protection and fi re resistance of building
elements to reduce the risk of structural damage and loss of life in the case
of a fi re.
366