Geoscience Reference
In-Depth Information
height:
h
=
0.75 m;
geotextile material: woven polypropylene (PP);
geotextile tensile strength:
T
m
=
120 kN/m;
geotextile strain at maximum tensile strength:
ε
m
=
0.14.
Required solution
Check the prescribed geotextile bags for stability in waves and current. Also deter-
mine if the tensile strength of the geotextile bags is sufficient if they are to be dumped
from a barge.
Calculation method
The design parameters are determined using formulae (3.5), (3.7) and (3.6):
2650 1000
1000
ρρ
−
Δ
t
−
−
=
(
)
(
)
)
s
s
w
w
=
(
091
n
−
=
⋅
⋅
)
0
ρ
w
w
2
gT
p
981475
2
2
=
814
.
L
35 23
.
23
m
=
=
0
2
π
2
π
⋅
⋅
tant
18 43
0. 5
35 23
α
an
ξ
.
2. 5
α
=
=
=
.
H
L
s
0
.
The effective thickness of the geotextile bag can be determined using formula (3.4):
D
k
=
L
⋅
sin
α
=
2.5
⋅
sin(18.43)
=
0.79 m
Stability subject to waves
The next step is to check the stability subject to waves. The slope has an incline of
1V:3H. Using formula (3.8):
H
D
s
≤
14
.
Δ
t
D
085
091 079
.
=
118
.
⇒
complies
.
⋅
.
For the geotextile bags that will be installed between SWL
±
H
s
the equilibrium is
determined using formula (3.10):
H
D
R
H
s
≤
0
7
90
+
09
c
790
+
.
Δ
t
D
s
11
085
does not comply
0790
+
09
091
.
=
=
⇒
790
+
.