Vulnerability assessment of reinforced concrete structures for fire and earthquake risk - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 373

620 ° C 760 ° C

400 C

298 ° C

° 620 C

525 ° C

°

277 ° C 500 ° C

Column A Column B

14.9 Temperature distributions assumed for the analysis, obtained
from test data by averaging maximum temperatures that each part
of the sections reached during the fi re exposure.

axial response of the two columns under axial loads. The analysis was done
considering degradation of the concrete material properties due to its expo-
sure to the elevated temperatures.
Load-deformation results from the numerical analysis were then com-
pared with the load-deformation ratio measured during the test. Figure
14.10 illustrates the comparison between the test and the numerical results
for the two columns. The fi gure shows a reasonable agreement between the
results, indicating a successful verifi cation of the numerical analysis
employed for the axial load response estimation. Furthermore, for compari-
son, the axial response of the two columns with no fi re exposure, using the
original properties, was also estimated and provided in the same fi gure. The
results show that residual axial capacity was reduced to 73% for Column
A; and 52% for Column B.

14.5.2 Lateral load resistance
VecTor3 was utilized to investigate the residual lateral load response of the
two column specimens after the fi re damage. One may be concerned that
validation of the numerical model for axial behavior would not apply for
lateral response simulation. This is true since lateral response of the columns
involves shear and fl exure mechanisms in addition to the axial mechanism.
It is noted that VecTor3 has been validated for such columns under lateral
load in ambient temperature. Since the two column specimens in this case
study are relatively long, their governing behavior would be axial and
fl exure when subjected to the lateral loads. In the analysis, each column
section is divided into small fi ber elements, hence the main impact on these
elements will be either axial compression or tension response. Furthermore,