Vulnerability assessment of reinforced concrete structures for fire and earthquake risk - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 362

Residual
displacement

600 mm

(a) (b)

14.1 Lateral deformation of columns due to the thermal expansion of
structures in fi re: (a) resembling the column failure during the fi re at
the Military Personnel Records Centre (USA) and (b) building frame
deformation due to thermal expansion.

building in the fi re endurance assessment (Mostafaei et al. 2011). For
instance, current fi re resistance standards require only a constant axial load
applied during the column fi re test. However, effects from lateral deforma-
tion due to thermal expansion of fl oors and change in axial load of the
column due to its interaction with the rest of the building are ignored.
Figure 14.1 shows an example of the column's lateral deformation due
to the thermal expansion in fi re. Figure 14.1a illustrates shear failure of a
column on the 6th fl oor of the US Military Personnel Records Centre build-
ing due to the fi re that occurred in 1973 (Beitel and Iwankiw 2002), and
Figure 14.1b demonstrates how the thermal expansion induces lateral
deformation to the columns. Although the response of reinforced concrete
columns under lateral loads has been studied for many years, a remaining
challenge has been the development of a reliable methodology for evaluat-
ing effects of such lateral deformation in performance of the structure in
fi re.

14.3 Seismic response of structures

Various standards and guidelines have been developed, worldwide, for
seismic design of structures. Based on the seismicity and site condition of
structures, methodologies have been developed for evaluating response of
the structures to the seismic loads and for designing and retrofi tting the
structures against such a hazard. The different approaches include equiva-
lent static seismic load and analyses, design based on the mode shapes,
dynamic and time history analyses.