Resumo (PT):
Abstract (EN):
. This paper presents a probabilistic fragility analysis for two groups of bridges: simply supported
and integral bridges. Comparisons are based on the seismic fragility of the bridges subjected to
accelerograms of two seismic sources. Three-dimensional finite-element models of the bridges were created
for each set of bridge samples, considering the nonlinear behaviour of critical bridge components. When the
seismic hazard in the site is controlled by a few seismic sources, it is important to quantify separately the
contribution of each fault to the structure vulnerability. In this study, seismic records come from earthquakes
that originated in strike-slip and reverse faulting mechanisms. The influence of the earthquake mechanism
on the seismic vulnerability of the bridges was analysed by considering the displacement ductility of the
piers. An in-depth parametric study was conducted to evaluate the sensitivity of the bridges’ seismic
responses to variations of structural parameters. The analysis showed that uncertainties related to the
presence of lap splices in columns and superstructure type in terms of integral or simply supported spans
should be considered in the fragility analysis of the bridge system. Finally, the fragility curves determine the
conditional probabilities that a specific structural demand will reach or exceed the structural capacity by
considering peak ground acceleration (PGA) and acceleration spectrum intensity (ASI). The results also
show that the simply supported bridges perform consistently better from a seismic perspective than integral
bridges and focal mechanism of the earthquakes plays an important role in the seismic fragility analysis of
highway bridges.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
22