Technical Paper by JP Giroud, KL Soderman and K. Badu-Tweneboah
Technical Paper by JP Giroud, KL Soderman and K. Badu-Tweneboah
Technical Paper by JP Giroud, KL Soderman and K. Badu-Tweneboah
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
GIROUD et al. D Optimal Configuration of a Double Liner System<br />
conditions are met for the simpler, but less general, Equation 4 (Bernoulli’s equation) to<br />
be applicable. According to Figure 6 of the paper <strong>by</strong> <strong>Giroud</strong> et al. (1997b), Equation 4<br />
is applicable fora defect with a diameter of2 mm <strong>and</strong> a leachate head on top of the primary<br />
liner of 0.01 m if the hydraulic conductivity of the leachate collection layer overlying<br />
the geomembrane liner is greater than 1 × 10 -1 m/s. According to Section 3.1, this condition<br />
is met. (It has also been checked that Equation 4 is applicable to the geomembrane<br />
primary liner in the three other cases considered in the comparative study.) Consequently,<br />
Equation 4 can be used as follows to calculate the rate of leachate migration through<br />
a defect in the geomembrane primary liner due to a leachate head of 0.01 m:<br />
Q 1<br />
= ¥ - 6<br />
(.)( 0 6 10 ) ()(. 2 9 81)(. 0 01) = 8.<br />
349 ¥ 10<br />
- 7 3<br />
p m /s<br />
The unit rate of leachate migration through the geomembrane primary liner is then<br />
calculated using Equation 3 as follows:<br />
q 1<br />
= ( 2. 5 ¥ 10 ) (8. 349 ¥ 10 ) = 2.<br />
087 ¥ 10<br />
- 4 - 7 -10<br />
m/s<br />
Average Head of Leachate on Top of the Secondary Liner. The methodology for calculating<br />
the average head of leachate is described in Section 2.2. The average head of<br />
leachate on top of the secondary liner due to the above calculated unit rate of leachate<br />
migration through the primary liner is calculated using Equation 1 as follows:<br />
-10<br />
( 2087 . ¥ 10 ) (50)<br />
h 2<br />
=<br />
= 2609 . ¥ 10<br />
( 2) ( 01 . ) ( 002 . )<br />
- 6 m<br />
Rate of Leachate Migration Through the Composite Secondary Liner. The methodology<br />
for calculating the rate of leachate migration through a composite liner due to a geomembrane<br />
defect is described in Section 2.3.5. The rate of leachate migration through<br />
the secondary liner resulting from the above calculated head is calculated using Equation<br />
11 as follows:<br />
L<br />
NM<br />
Q 2<br />
= 021 . 1+<br />
01 .<br />
= 4.<br />
044 ¥ 10<br />
F<br />
HG<br />
-15<br />
2.<br />
609 ¥ 10<br />
-3<br />
7 ¥ 10<br />
3<br />
m /s<br />
-6<br />
I<br />
KJ<br />
095 .<br />
O<br />
QP<br />
- - -<br />
( p ¥ 10 ) ( 2. 609 ¥ 10 ) ( 1 ¥ 10 )<br />
6 01 . 6 0. 9 11 0.<br />
74<br />
The unit rate of leachate migration through the composite secondary liner is then calculated<br />
using Equation 3 as follows:<br />
q 2<br />
= ( 2. 5 ¥ 10 ) ( 4. 044 ¥ 10 ) = 1011 . ¥ 10<br />
- 4 - 15 -18<br />
m/s<br />
382 GEOSYNTHETICS INTERNATIONAL S 1997, VOL. 4, NOS. 3-4
Change language