Geoscience Reference
In-Depth Information
Where a filled geotextile mattress has to be hoisted or dragged into place without
causing damage a high strength bottom geotextile layer is required.
4.5.2 Required tensile strength
The required tensile strength of a geotextile mattress is largely governed by the method
of construction. During filling, hoisting and pulling, and placement, major drag and
tensile loads can be exerted on the geotextile mattress. In addition to the strength of
the geotextile and the seams, anchoring at the edges is also an important aspect.
Hoisting
Where a clamping system is used, the maximum tensile load in the geotextile mattress
during the hoisting process (see Figure 4.3) can be determined as:
lb D
b
b
⋅
=
m
D
(4.2)
T
⋅⋅
ρ
g
g
where:
T
=
tensile load per unit width in the geotextiles in the mattress [N/m];
l
=
length of the geotextile mattress [m];
m
=
width of the geotextile mattress [m];
b
g
=
width of the geotextile [m];
D
k
=
effective thickness of the geotextile mattress [m];
ρ
=
density of the geotextile mattress [kg/m
3
];
g
=
acceleration due to gravity [m/s
2
].
I
Figure 4.3
Tensile loads in geotextile mattress during hoisting.
