Civil Engineering Reference
In-Depth Information
a large amount of transverse steel reinforcement needs to be employed. Examples of shear failure modes
in RC columns are provided in Figures B.6 and B.7. These failures demonstrate that inadequate seismic
detailing, especially in the critical zones at the ends of the members, and interaction with masonry
infi lls can cause extensive damage in columns during earthquakes. The Van Nuys Holiday Inn was a
seven-storey instrumented building located approximately 7.0 km east of the epicentre of the 1994
Northridge earthquake. This building experienced a peak horizontal acceleration of 0.47 g at base and
0.59 g at the roof. It suffered serious structural damage in all columns of the third fl oor where signs of
a shear-bond splitting type of failure were observed (inset of Figure B.6). The Holiday Inn structure
had already suffered extensive non-structural damage during the 1971 San Fernando earthquake.
A sealed separation gap between the brick wall and the columns of the frame in Figure B.7 could
have avoided the structural damage experienced by the RC structure.
Part of the damage in the corner columns of adjacent frames in Figure B.7 may also be attributable
to pounding, i.e. mutual impact due to out-phase motion of the two structures, which is discussed in
Appendix A.
Figure B.6
Shear failure in columns during the 1994 Northridge (California) earthquake in the Van Nuys Holiday
Inn (
left
) and in the 1998 Adana-Ceyhan (Turkey) earthquake (
right
)
Figure B.7
Shear failures in columns due to interaction with masonry infi lls in the 1998 Adana-Ceyhan earth-
quake: short-column effects and shear failure due to the presence of a masonry wall on a single side of the
column
