Performance and Analysis of Arifiye Overpass Reinforced Earth Walls During the 1999 Kocaeli (Turkey) Earthquake - Reinforced Soil Engineering: Advances in Research and Practice - page 434

with steel strips and compacted granular backfill. The abutment was supported on
piles, and the RE walls and approach fills rested on a thin layer of fill overlying
natural ground.
Four spans of the bridge collapsed in a “sawtooth” manner due to lateral
displacements of the peirs and abutments, along with inadequate beam seat
widths. However, the RE walls remained intact and experienced relatively little
damage. In fact, the minor damage that occurred was associated with the
settlement/partial collapse of a culvert that ran beneath the wall and caused a loss
of foundation support beneath one section of the wall. This resulted in separation
and loss of interlocks between some of the lower wall panels, which, in turn,
caused some minor spillage of backfill material. The damage was not at all
associated with internal shearing mechanisms of the walls.
Because there are few data regarding the seismic field performance of RE
walls, the authors recognized the importance of this site and documented the
behavior, including measurements of wall displacements and fault-related ground
movements. The subsoil conditions and construction plans for the walls were also
obtained during the investigation. These data made it possible for the authors to
perform numerical analyses to predict the observed wall behavior. This chapter
provides a description of the RE walls and their seismic performance, along with
the methodology and results of a detailed numerical analysis. The study is
thought to provide important insight into RE behavior under seismic loading and
yield data that can be used to improve our predictive capabilities and design
procedures.

2 CASE STUDY: ARIFIYE BRIDGE OVERPASS

The Arifiye Bridge overpass, which was constructed in 1988 and destroyed in the
1999 earthquake, consisted of four simply supported spans resting on approach
abutments and three mid-span pier supports. The site is located along the Trans
European Motorway at the zone of energy release, as the surficial fault rupture
passed directly beneath the site; see Fig. 1 . A schematic of the site developed
from an aerial photograph taken by the authors is shown in Fig. 2 .
The wing walls of the northern approach abutment were constructed using
reinforced earth (RE). The RE walls were 10m high and of conventional design,
consisting of square, interlocking reinforced concrete panels as facing elements.
The panels were 150 cm

150 cm in the frontal area, and the reinforcing
elements were ribbed, galvanized steel strips with a cross section of
40mm

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5 mm. Typically, four strips were used per panel at a horizontal
spacing of 75 cm. The backfill soil was of good quality, consisting of sand and
gravel that was compacted in lifts during wall construction. A cross section of the
maximum section of the double-walled abutment is given in Fig. 3. The abutment

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