Geosynthetics April/May 2023 - 19

open-water surface of the ramp. To ensure
there were no sharp objects in the excavation,
divers checked the underground.
In a later stage, the water was pumped
out of the pit to submerge the geomembrane.
Therefore, a drainage system was
installed on the bottom of the pit.
The first layer installed was a protection
geotextile. This layer was prefabricated
in five big rolls of 23 feet (7
m) width because of the volume (thickness)
of the geotextile. The rolls were
transported to the project, unrolled and
stitched together to one part of 65 feet² (6
m2) (Figure 3). In front of the geotextile,
an air tube was stitched for preventing
the layer from sinking during pull over
(Figure 4).
After compiling the geotextile layer,
it was pulled over the water surface by
using winches and cables (Figure 5). The
pulling must be performed in one continuous
movement because the geotextile
that is heavier than water wants to sink.
Once on the other side, the excess length
was pulled onto the water surface, and
the geotextile was allowed to sink to the
bottom of the pit (Figure 6).
The second layer installed was the
PVC-P geomembrane. The total needed
surface for each ramp (65 feet² [6 m2])
was prefabricated into two parts of 32.5
feet² (3 m2) (Figure 7). The prefabricated
parts were folded and rolled on a 23 foot
(7 m) long steel pipe. The two parts were
unrolled at the project site and welded
together into one large membrane construction.
The same winches and cables
were used to pull the membrane across
the water's surface.
After the excess length was pulled
onto the water surface, and before the
submerging process could be started, the
connection to the geomembrane from the
tunnel part was made. The geomembrane
from the tunnel and the pulled-over part
were pulled onto a raft, cleaned and then
welded together. After removing the
FIGURE 6 Overhead view of the geotextile starting to sink
FIGURE 5 Another view of pulling the geotextile across the water surface
FIGURE 7 Geomembrane prefabrication
GeosyntheticsMagazine.com
19

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Geosynthetics April/May 2023

Table of Contents for the Digital Edition of Geosynthetics April/May 2023

Geosynthetics April/May 2023 - Cover1
Geosynthetics April/May 2023 - Cover2
Geosynthetics April/May 2023 - 1
Geosynthetics April/May 2023 - 2
Geosynthetics April/May 2023 - 3
Geosynthetics April/May 2023 - 4
Geosynthetics April/May 2023 - 5
Geosynthetics April/May 2023 - 6
Geosynthetics April/May 2023 - 7
Geosynthetics April/May 2023 - 8
Geosynthetics April/May 2023 - 9
Geosynthetics April/May 2023 - 10
Geosynthetics April/May 2023 - 11
Geosynthetics April/May 2023 - 12
Geosynthetics April/May 2023 - 13
Geosynthetics April/May 2023 - 14
Geosynthetics April/May 2023 - 15
Geosynthetics April/May 2023 - 16
Geosynthetics April/May 2023 - 17
Geosynthetics April/May 2023 - 18
Geosynthetics April/May 2023 - 19
Geosynthetics April/May 2023 - 20
Geosynthetics April/May 2023 - 21
Geosynthetics April/May 2023 - 22
Geosynthetics April/May 2023 - 23
Geosynthetics April/May 2023 - 24
Geosynthetics April/May 2023 - 25
Geosynthetics April/May 2023 - 26
Geosynthetics April/May 2023 - 27
Geosynthetics April/May 2023 - 28
Geosynthetics April/May 2023 - 29
Geosynthetics April/May 2023 - 30
Geosynthetics April/May 2023 - 31
Geosynthetics April/May 2023 - 32
Geosynthetics April/May 2023 - 33
Geosynthetics April/May 2023 - 34
Geosynthetics April/May 2023 - 35
Geosynthetics April/May 2023 - 36
Geosynthetics April/May 2023 - 37
Geosynthetics April/May 2023 - 38
Geosynthetics April/May 2023 - 39
Geosynthetics April/May 2023 - 40
Geosynthetics April/May 2023 - 41
Geosynthetics April/May 2023 - 42
Geosynthetics April/May 2023 - 43
Geosynthetics April/May 2023 - 44
Geosynthetics April/May 2023 - Cover3
Geosynthetics April/May 2023 - Cover4
https://www.nxtbook.com/ata/geosynthetics/geosynthetics-case-studies-guide-2024
https://www.nxtbook.com/ata/geosynthetics/geosynthetics-april-may-2024
https://www.nxtbook.com/ata/geosynthetics/geosynthetics-february-march-2024
https://www.nxtbook.com/ata/geosynthetics/geosynthetics-december-2023-january-2024
https://www.nxtbook.com/ata/geosynthetics/geosynthetics-october-november-2023
https://www.nxtbook.com/ata/geosynthetics/geoysynthetics-august-september-2023
https://www.nxtbook.com/ata/geosynthetics/geosynthetics-june-july-2023
https://www.nxtbook.com/ata/geosynthetics/geosynthetics-april-may-2023
https://www.nxtbook.com/ata/geosynthetics/geosynthetics-february-march-2023
https://www.nxtbook.com/ata/geosynthetics/geosynthetics-december-2022-january-2023
https://www.nxtbook.com/ata/geosynthetics/geosynthetics-october-november-2022
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-august-september-2022
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-june-july-2022
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-april-may-2022
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-february-march-2022
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-december-2021-january-2022
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-october-november-2021
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-august-september-2021
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-june-july-2021
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-april-may-2021
https://www.nxtbook.com/ifai/geosynthetics/geosynthetics-february-march-2021
https://www.nxtbook.com/ifai/geosynthetics/1220GS
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https://www.nxtbook.com/ifai/geosynthetics/0418GS
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