Publication Date:
2017-04-04
Description:
The Mw 7.1 earthquake of November 12, 1999 severely damaged a 2.5 km long viaduct on a stretch under
construction of the Istanbul-Ankara motorway, 18 km W of Bolu. The fault rupture crossed the viaduct with
an observed offset close to 1.5 m; the viaduct deck suffered large permanent displacements but did not collapse.
Seismic hazard at the site appears to be governed by characteristic earthquakes occurring every few hundred years
both on the Düzce fault and on the main stretch of North Anatolian fault (NAF). Smaller active faults near the
site also contribute to the hazard. We investigate how a reliable design response spectrum of displacement can be
constructed for the viaduct site using both probabilistic and deterministic tools. After checking the applicability of
known attenuation relations against recorded data, we illustrate a hazard analysis that incorporates a characteristic
earthquake model for the relevant faults, and accounts for statistical directivity effects on the Düzce fault. Constantrisk
response spectra up to 3 s are thus obtained for different return periods. Synthetic motions at the site are
generated next, using a known source model, in order to explore the features of the displacement response spectrum
at vibration periods in the range between 1s and 6 s, in which the dominant response of the viaduct deck, uncoupled
from the piers, occurs. A discussion of results follows.
Description:
Published
Description:
307-327
Description:
3T. Pericolosità sismica e contributo alla definizione del rischio
Description:
JCR Journal
Description:
restricted
Keywords:
1999 Turkey earthquakes
;
bridge retrofitting
;
characteristic earthquake
;
displacement response spectrum
;
long period ground motion
;
source directivity
;
seismic hazard
;
04. Solid Earth::04.06. Seismology::04.06.11. Seismic risk
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
