Geoscience Reference
In-Depth Information
4
4
3
2
Fit Equation :
log(Y)
=
1.55
x
log(x)
Fit Equation (Steel):
log(Y)
=
0.88
x
log(x)
3
−
8.15
−
5.28
R-squared
=
0.86
R-squared
=
0.90
2
0.100
9
7
6
5
4
3
2
Steel
Cl
Dl
AC
0 .10
9
8
7
6
5
Fit Equation (CI):
log(Y)
=
1.21
x
log(X)
0.010
4
9
−
6.78
8
R-squared
=
0.84
Fit Equation (Dl):
log(Y)
=
1.88
x
log(X)
7
3
6
5
1994 North ridge
1989 Loma Prieta
1987 Whittier Narrows
1971 San Fernando (south)
−
9.39
4
2
R-squared
=
0.73
Fit Equation (AC):
log(Y)
=
2.26
x
log(X)
3
2
−
11.02
R-squared
=
0.71
0.001
0 .01
10
2
3
4
5
6
7
8
9
100
10
2
3
4
5
6
7
8
9
100
PGV (cm/sec)
PGV (cm/sec)
b) Steel, CI, DI and AC
Distribution Lines
Fig. 17.8. Pipeline repair rate correlation withPGV forsteel, CI,DI, and AC
distributionlines
a) CI Distribution Lines
and are subject to corrosion that has been shown to intensify their damage rates in previ-
ous earthquakes (Isenberg, 1979).
TheregressionsinFigure17.8weredevelopedafterthedatawerescreenedforlengthsof
pipeline that represent approximately 1.5% to 2.5% of the total length or population for
each type of pipe affected by the earthquake (O'Rourke and Jeon, 1999). This procedure
reduces the influence of local erratic effects that bias the data derived from small lengths
of pipeline. The use of this filtering procedure leads to statistically significant trends and
regressions that are applicable for PGV
75cm s
−
1
. For the Northridge earthquake,
zones with PGV exceeding 75cm s
−
1
generally correspond to locations where PGD,
from sources such as liquefaction and landsliding, was observed. Hence, this screening
techniquetendstoremovedamageassociatedwithPGD,resultingincorrelationsrelevant
for TGD.
≤
4. Large-scale tests of ground rupture effects on steel pipelines with elbows
A key component of modern research involving geotechnical engineering for extreme
loading conditions has been testing at very large scale. This paper refers to three pro-
grams involving large scale experiments that were performed to evaluate the effects
of earthquake-induced ground rupture on welded steel and high density polyethylene
(HDPE) pipelines.
