Geoscience Reference
In-Depth Information
CYCLIC STRESS RATIO, CSR
CYCLIC STRESS RATIO, CSR
CYCLIC STRESS RATIO, CSR
0.1
0.15
(SM)
0.2
0.25
0.3
0.35
0
0.05
0.1
0.15
0.2
0
0.04
0.08
0.12
0.16
0.2
0
0
0
FILL
(CL)
(CL)
(GM)
(GC)
(SC)
5
5
5
(GC)
(SM)
(CL)
(SM)
10
10
10
(CH, CL)
(CL)
(CL)
15
15
15
(GM)
(SC)
20
20
20
(CL)
T8 (ST38)
(CH, CL)
(CH, CL)
R7 (ST51)
R8 (ST31)
25
25
25
0
100
200
300
400
500
0
100
200
300
400
0
100
200
300
400
500
0
0.1
0.2
0.3
0
0.05
0.1
0.15
0.2
0.25
0.2
0
0.3
0.4
0.5
0
0
FILL
FILL
FILL
(CL)
(GC)
5
5
5
(GM)
(CL)
(SM)
10
10
10
(SC)
SP, SM
(SC)
15
15
15
(CL)
Youd et al., 2001
site response
Cetin et al., 2004
20
20
20
P7 (ST45)
G11 (SKE27)
Q10 (ST4)
25
25
25
0
100
200
300
400
500
0
200
400
600
0
200
400
600
Shear Wave Velocity (m/sn)
Shear Wave Velocity (m/s)
Shear Wave Velocity (m/s)
Fig. 4.9. Comparisons ofCSR by siteresponse analysis and r
d
simplified procedure
recommended byYoud et al. (2001) and Cetin et al. (2004)
The severity of possible liquefaction at any site was quantified by introducing a factor
called the liquefaction potential index, PL, defined as
F
P
L
=
(
)
(
)
z
w
z
dz
(4.3)
where z is the depth below the ground water surface, measured in metres; F(z) is a
function of the liquefaction resistance factor, FL, where F
(
z
)
=
1-FLbutifFL
>
1
.
0,
F
(
z
)
=
0; and w
(
z
)
=
10-0
.
5z. Eq. (4.3)gives values of PL ranging from0 to 100.
Based on the results reported by Iwasaki et al. (1982), three zones (A, B, and C) were
identified with respect to liquefaction potential index. Zone C is where the liquefaction
potentialindexisPL
>
15,zoneBistheintermediatezonewheretheliquefactionpoten-
≤
≤
tial index is 5
PL
15, and zone A is the safest zone where liquefaction potential
<
index is PL
5.
