Civil Engineering Reference
In-Depth Information
Figure B.14
Collapses caused by torsional effects in RC multi-storey buildings during the 1999 Kocaeli (Turkey)
(
left
) and the 1999 North Athens (Greece) earthquakes (
right
)
Figure B.15
Collapse of the multi-storey perimeter frame of the California State University Campus during the
1994 Northridge earthquake: global view (
left
) and close-up of the damage in the frame (
right
)
ment, or shear compression failure in the columns. Furthermore, a catenary action was provided by
the fl oor slab, which caused an 'implosion' of part or all of the structure. Typically, precast RC frames
for industrial buildings, as shown for example in Figure B.16, possess low redundancy. Collapses for
these types of constructions are also attributed to the inadequate seismic detailing of the connections.
Smoothed bars with insuffi cient anchorage lengths are shown in Figure B.16 .
• Hammering of two adjacent structural systems during an earthquake causes pounding as illustrated
in Section A.1.2. This failure mode is caused by insuffi cient spacing between adjacent buildings,
which should accommodate the relative displacements under earthquake ground motions. Buildings
with different confi gurations and different materials of construction may be either in phase or in
opposition of phase when oscillating. If they are suffi ciently close to each other, the frames impact
and both may suffer signifi cant structural damage. Adequate separation gaps should be used to prevent
these failure modes. Historical data from past earthquakes show that pounding of adjacent buildings
has caused enormous losses (Bertero, 1996). This is a typical mechanism of failure that happens
