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

GIROUD et al. D Leachate Flow in Leakage Collection Layers Due to Geomembrane Defects
more convenient for theoretical analyses as well as practical applications. However, if
the actual surface area of the wetted zone, A w actual , were needed, it could be derived from
the surface area given above using the following equation:
A = A /cosb
(63)
wactual
The various widths of the wetted zone are unchanged in the projection.
4.3.5 Surface Area of the Wetted Zone in the Case Where the Leakage Collection Layer
is not Full
Combining Equation 10 with Equations 49 to 62 gives the following equations for the
case where the leakage collection layer is not full (t o < t LCL ), i.e. when the condition expressed
by Equation 11 (or Equation 12, which is equivalent) is met:
S When the parabola is complete, i.e. when the following conditions are met:
w
Q/
k
L
2 sinb £
(64)
and
Q/
k
X L
2 sinb £ £
(65)
the latter being equivalent to
0
£ x £ L -
2
Q/
k
sinb
(66)
the surface area of the wetted zone is expressed by
A = ( 4/ 3)( 2/sin b) ( Q/ k)
X
w
F
HG
12 / 14 / 32 /
2Q
x
Aw = 1+
2 sin b
2
3k
sin b Q/
k
I
KJ
32 /
(67)
(68)
S When the parabola is truncated, the surface area of the wetted zone is expressed by:
Aw = ( 4/ 3)( 2/sin b) ( Q/ k) X - ( X - L)
L
MF
NHG
12 / 14 / 32 / 32 /
2 Q 2 x sinb
2( L - x) sinb
Aw = 1 +
- 1 -
2
3 k sin b M Q/
kKJ Q/
k
I
F
HG
I
KJ
32 / 32 /
O
QP
(69)
(70)
238 GEOSYNTHETICS INTERNATIONAL S 1997, VOL. 4, NOS. 3-4