Civil Engineering Reference
In-Depth Information
FIGURE 4.5
Damage due to a soft story at the ground floor. The
damage occurred during the Chi-chi earthquake in Taiwan on
September 21, 1999. (
Photograph from the USGS Earthquake
Hazards Program, NEIC, Denver.
)
garage area, with its large open areas, had inadequate shear resistance and was unable to
resist the earthquake-induced building movements.
4.
Izmit earthquake in Turkey on August 17, 1999:
Details concerning this earthquake
have been presented in Sec. 3.3. In terms of building conditions, it has been stated (Bruneau
1999):
A typical reinforced concrete frame building in Turkey consists of a regular, symmetric
floor plan, with square or rectangular columns and connecting beams. The exterior enclosure
as well as interior partitioning are of non-bearing unreinforced brick masonry infill walls.
These walls contributed significantly to the lateral stiffness of buildings during the earthquake
and, in many instances, controlled the lateral drift and resisted seismic forces elastically. This
was especially true in low-rise buildings, older buildings where the ratio of wall to floor area
was very high, and buildings located on firm soil. Once the brick infills failed, the lateral
strength and stiffness had to be provided by the frames alone, which then experienced signifi-
cant inelasticity in the critical regions. At this stage, the ability of reinforced concrete columns,
