Geoscience Reference
In-Depth Information
Requested
Check whether this geotextile complies with regard to excess pressure, blocking and
clogging.
Calculation
Using formula (A.4):
ki
ΨΔ
⋅
H
i
=
s
i
s
Now, the hydraulic gradient
i
s
in the geotextile container can be determined from
(where
B
s
is the width of the geotextile container):
H
B
Δ
05
0 071
.
i
=
=
=
s
7
s
With the geotextile properties as stated by the supplier, a check can be made on
whether the excess pressure is low enough. It must comply with formula (A.5):
ki
s
Δ
H
i
s
≤
001
.01 m
=
Ψ
Substituting the various values in the above relationship gives:
ki
s
4
0 071
008
10
−
⋅
H
=
5
complies
.
Δ
i
s
89 10
−
m
⇒
=
=⋅
9 10
Ψ
Blocking occurs if the following conditions are present at the same time:
A uniform opening size of the geotextile;
A uniform grain-size distribution of the fill material;
O
06
02
90
complies.
05
10
3
t
=
05
10
⇒
=⇒
3
5
1
D
90
Therefore, there is little possibility of blocking.
The last step is to check for clogging. This will not occur if:
O
06
01
90
complies
3
6
>⇒
3
=⇒
6
D
15
The check shows that the geotextile prescribed by the supplier complies and can
be used.
