Geoscience Reference
In-Depth Information
Sliding Response
Dynamic Response
Decoupled
Analysis
Rigid Block
Flexible System
Calculate HEA-
time history
assuming no
sliding along base
Double
integrate HEA-
time history
given ky to
calculate U
Earth Fill
Dynamic Response and
Sliding Response
Potential Slide Plane
Flexible System
Coupled
Analysis
Max Force at
Base = k
y
·W
Fig. 14.3. Decoupled dynamic response/rigid slidingblock analysis
and fullycoupled analysis
EARTH FILL
H
H
Potential Slide Plane
(a)
T
s
= 4 H / V
s
(b)
T
s
= 2.6 H / V
s
H
(c)
T
s
= 4 H / V
s
Fig. 14.4. Estimatingthe initialfundamental period of potential slidingblocks
(Figure 14.3). In addition, its validation against shaking table experiments provides
confidence in its use(Wartman et al., 2003).
For seismicdisplacement methods that incorporate the seismic response of a deformable
sliding block, the initial fundamental period of the sliding mass
(
T
s
)
can normally be
estimated using the expression:
T
s
V
s
for the case of a relatively wide potential
slidingmassthatiseithershapedlikeatrapezoidorsegmentofacirclewhereitsresponse
islargely1D(e.g.,RathjeandBray,2001),where
H
=
4
H
/
theaverageheightofthepotential
slidingmass,and
V
s
istheaverageshearwavevelocityoftheslidingmass.Forthespecial
case of a triangular-shaped sliding mass that largely has a 2D response, the expression:
T
s
=
=
.
/
V
s
shouldbeused.Examplesofthemannerinwhich
T
s
shouldbeestimated
are shown inFigure 14.4.
2
6
H
