Effect of soil–structure interaction and spatial variability of ground motion on seismic risk assessment of bridges - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 601

22.3 Plastic strains developed at the backfi ll of the approach
embankment of the TY3 bridge (transverse direction).
behavior of the embankment and backfi ll soil under high levels of shear
strain, even if the bridge superstructure remains linear. Another reason is
the mobilization of the embankment mass during strong ground shaking
which may act as a signifi cant source of seismic energy that is transmitted
to the bridge through the embankment-abutment-deck boundaries. In such
a case, inertial and kinematic interaction effects between the bridge and the
approach embankments may be signifi cant, especially in the transverse
direction. Moreover, in case of short bridges, the embankments may drive
the overall response of the bridge (Zhang and Makris, 2002b), thus forcing
the central piers follow the large, almost rigid body, displacements imposed
by the deck-abutment system. This is a problem as it is strongly frequency
dependent and has the signifi cant implication that conventional response
modifi cation factors prescribed in bridge design codes ( R in the US and q
in Europe) in order to reduce pier forces depending on the bridge system
period and ductility, may not be applicable (Kotsoglou and Pantazopoulou,
2009). Notwithstanding the above advances in understanding dynamic
embankment-abutment-deck interaction therefore, further research is
warranted.