leachate flow in leakage collection layers due to defects in ...

GIROUD et al. D Leachate Flow in Leakage Collection Layers Due to Geomembrane Defects
S If μ ≥ 2(whereμ is defined by Equation 111)
L
MF
NHG
32 /
2 F ( Q/ k)
2 L sinb
2 L sinb
Rwrand = 1 +
+ 1 -
3
15 L sin b M Q/
kKJ Q/
k
I
52 /
F
HG
I
KJ -
2
O
QP
(130)
Combining Equation 17 with Equations 121 and 126, respectively, gives the following
values of R w rand for the case where the leakage collection layer is full (t o > t LCL ), i.e.
the case where the condition expressed by Equation 11 (or Equation 12, which is equivalent)
is not met:
S If μ ≤ 2(whereμ is defined by Equation 112)
R
w rand
L
F
IO
R
L
S|
M
N
M
T|
3
F tLCL
Q
= +
L N
M 1
HG
ktLCLKJ
Q
P 1+
2
60 sinb
| M
t
S If μ ≥ 2(whereμ is defined by Equation 112)
R
w rand
L
F
IO
R
L
S|
M
N
M
T|
3
F tLCL
Q
= +
L N
M 1
HG
ktLCLKJ
Q
P 1+
2
60 sinb
| M
t
LCL
4 L sinb
F
HG
Q
1 +
2
kt
LCL
LCL
O
I
KJ
Q
P
4 L sinb
F Q
1 +
2
kt
HG
L
N
M
+ 1 -
t
LCL
LCL
O
I
KJ
Q
P
52 /
4 L sinb
F
HG
Q
1 +
2
kt
- 2
LCL
U
V|
W|
O
I
KJ
Q
P
52 / 52 /
(131)
- 2
U
V|
W|
(132)
4.4.5 Critical Values of the Wetted Fraction in the Worst Scenario and the Random
Scenario
In Section 4.4, so far, it has been assumed that the wetted zones related to the various
geomembrane defects do not overlap. The critical value of R w worst ,Crit(R w worst ), is the
maximum value that R w worst can have without overlapping of the wetted zones related
to the various individual primary liner defects. This occurs when the parabolic wetted
zones shown in Figure 9a are in contact at the low end of the leachate collection layer
slope (Figure 11). This situation occurs when:
W = max
B / N
Combining Equations 98, 100 and 133 gives:
F =
1
LW max
(133)
(134)
250 GEOSYNTHETICS INTERNATIONAL S 1997, VOL. 4, NOS. 3-4