Civil Engineering Reference
In-Depth Information
Table 4.1
Empirical correlation equations which can be used to predict the correlation
between the logarithm of two intensity measures for a given earthquake rupture,
ρ
ln
IM
i
,ln
IM
l
|
Rup
IM
SA
(
T
)
PGA
PGV
ASI
SI
DSI
CAV
Ds
575
Ds
595
IA
SA
(
T
)
BJ08
B11(a),
B07
B11(b)
B11(a)
B11(a)
B11(c)
B11(d)
B11(e)
B11(e)
B07
PGA
-
B11(b)
B11(a)
B11(a)
B11(c)
B11(d)
B11(e)
B11(e)
B07
PGV
-
B11(b)
B11(b)
B11(c)
B11(d)
B11(e)
B11(e)
-
ASI
-
B11(a)
B11(c)
B11(d)
B11(e)
B11(e)
-
SI
-
B11(c)
B11(d)
B11(e)
B11(e)
-
DSI
-
B11(d)
B11(e)
B11(e)
-
CAV
-
B11(e)
B11(e)
-
Ds
575
symmetric
-
B11(e)
-
Ds
595
-
-
IA
-
B07
=
Baker (2007); BJ08
=
Baker and Jayaram (2008); B11(a)
=
Bradley (2011c); B11(b)
=
Bradley (2010c); B11(c)
=
Bradley (2011b); B11(d)
=
Bradley (2011d); B11(e)
=
Bradley
(2011a).
Source: Bradley (2012b).
Boore and Atkinson (2008) (
SA
,
PGA
,
PGV
); Bradley (2009) (
ASI
); Bradley
et al.
(2009b) (
SI
); Bradley (2011b) (
DSI
); Campbell and Bozorgnia (2010)
(
CAV
); and Bommer
et al.
(2009) (
Ds
575,
Ds
595). References for the
various empirical correlation equations for each of the potential
IM
i
com-
binations are given in Table 4.1.
The ground motion selection methodology also requires the specifi cation
of a conditioning intensity measure,
IM
j
. Herein,
SA
(3.0) is used as the
IM
j
.
As noted by Bradley (2012a, 2012b), an
IM
j
should be selected which rep-
resents the amplitude of ground motion near the range of vibration fre-
quencies which control the governing seismic response mechanisms.
Importantly, as demonstrated by Bradley (2012a), the use of the discussed
ground motion selection method can consistently achieve results which are
independent of the selected
IM
j
.
4.5
Ground motion selection using generalized
conditional intensity measure (GCIM)
The benefi t of the GCIM approach is that
IM
|
IM
j
provides the exact dis-
tribution of intensity measures of potential ground motions with
IM
j
im
j
which may be observed at the site. The GCIM distributions are therefore
the 'target' that should be used in selecting a set of ground motions for
seismic response analysis. The theory underlying a semi-automated proce-
dure for selection of ground motions using the GCIM distribution is fi rstly
presented below, followed by examples elucidating its salient features.
=
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