It is
widely
known that topographic irregularities
influence the surface
ground motions,
typically
with a
n
enhancement of
the response close to convex topographic features
,
such as ridges and slope crests.
Several
studies
have
in
vestigat
ed
the ground motion
at the surface of filled valleys and empty canyons, focus
ing
mainly
on
the geometry and the soil
characteristics rather than the input excitation.
F
urther investigation of th
e impact of the input excitation to the ground
surface response is needed in order to
modify
existing ground motion prediction models to account for topographic effects.
The response of
canyons has been previously examined; but mainly focusing on
simple wa
velet input
. This paper considers
a fully weathered canyon (i.e., without any in
-
fill material) aiming to investigate the influence of
the input
excitation
on the
surface ground motion through a parametric time
-
domain finite element (FE) study. A two
-
dimen
sional plane
-
strain model
of an
idealised
canyon is considered for vertically propagating SV waves, using
both
wavelets
and recorded earthquakes
as input excitation. The model consists of two step
-
like slopes with slope height (H), in a homogeneous linear
elastic soil
layer overlying rigid bedrock.
Topographic aggravation is presented for several points along the canyon ground surface
aiming to derive a pattern of its distribution considering input excitation with different characteristics.