Geosynthetics April/May 2022 - 35

adjustments to increase stability are possible,
as shown in Figures 3b-3d. In Figure
3b, while the net surcharge load on the
foundation soils will be higher versus a
full-height MSE wall with UL-FGA backfill,
this layout may still be competitive
with other lightweight fill options that
are available (i.e., expanded shale or clay,
or cellular concrete). Figure 3c shows
extending the reinforcements into typical
unit weight reinforced fill. The approach
in Figure 3d is to cut the existing soils
back to a stable angle and fill the triangle
formed between the reinforced fill and
cut slope with additional UL-FGA. This
method, while increasing the quantity
of the UL-FGA, will greatly decrease the
lateral earth pressures on the wall from
the UL-FGA retained backfill.
Additional UL-FGA/
MSE considerations
Other design details that are typically
considered for MSE walls include drainage,
foundation preparation and wallfacing
details. Drainage piping may be
included within the UL-FGA to outlet
water from the retained soil, but the
entire layer will be highly permeable.
Piping may be used to outlet low spots
within the UL-FGA backfill, so any collected
water is allowed to outlet instead of
infiltrate into the foundation soil.
On all walls with UL-FGA backfill that
are under roadways, the pavement section
should be analyzed to ensure that the
distance between the top of pavement and
the top of UL-FGA layer is sufficient for
the pavement design requirements. It is
not unusual for this distance to be 3-4 feet
(914-1,219 mm) not only to address a flexible
pavement design, but also to accommodate
moment slabs for traffic barriers,
guide rail, fencing or buoyancy concerns.
Standard compaction procedures for
soils and traditional aggregates should not
be applied to UL-FGA. The compaction
3a
UL-FGA
FACING
REINFORCED FILL
RETAINED
BACKFILL
REINFORCEMENT (TYP.)
GEOTEXTILE
SEPARATION FABRIC
LEVELING PAD
FOUNDATION
SOIL
3b
FACING
(a)
UL-FGA
REINFORCED FILL
RETAINED
BACKFILL
TYP. UNIT WEIGHT
REINFORCED
FILL
REINFORCEMENT (TYP.)
GEOTEXTILE
SEPARATION FABRIC
LEVELING PAD
FOUNDATION
SOIL
(b)
3c
UL-FGA
FACING
REINFORCED FILL
TYP. UNIT WEIGHT
REINFORCED
FILL
RETAINED
BACKFILL
REINFORCEMENT (TYP.)
LEVELING PAD
FOUNDATION
SOIL
3d
UL-FGA
FACING
REINFORCED FILL
(c)
UL-FGA
RETAINED
BACKFILL
REINFORCEMENT (TYP.)
GEOTEXTILE
SEPARATION FABRIC
GEOTEXTILE
SEPARATION FABRIC
LEVELING PAD
FOUNDATION
SOIL
FIGURES 3a-3d MSE wall (a) with full-height UL-FGA MSE backfill, (b) with 50% height MSE
backfill, (c) with combination UL-FGA and typical unit weight MSE backfill, and (d) with ULFGA
MSE backfill and UL-FGA retained backfill
(d)
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35

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Geosynthetics April/May 2022

Table of Contents for the Digital Edition of Geosynthetics April/May 2022

Geosynthetics April/May 2022 - Cover1
Geosynthetics April/May 2022 - Cover2
Geosynthetics April/May 2022 - 1
Geosynthetics April/May 2022 - 2
Geosynthetics April/May 2022 - 3
Geosynthetics April/May 2022 - 4
Geosynthetics April/May 2022 - 5
Geosynthetics April/May 2022 - 6
Geosynthetics April/May 2022 - 7
Geosynthetics April/May 2022 - 8
Geosynthetics April/May 2022 - 9
Geosynthetics April/May 2022 - 10
Geosynthetics April/May 2022 - 11
Geosynthetics April/May 2022 - 12
Geosynthetics April/May 2022 - 13
Geosynthetics April/May 2022 - 14
Geosynthetics April/May 2022 - 15
Geosynthetics April/May 2022 - 16
Geosynthetics April/May 2022 - 17
Geosynthetics April/May 2022 - 18
Geosynthetics April/May 2022 - 19
Geosynthetics April/May 2022 - 20
Geosynthetics April/May 2022 - 21
Geosynthetics April/May 2022 - 22
Geosynthetics April/May 2022 - 23
Geosynthetics April/May 2022 - 24
Geosynthetics April/May 2022 - 25
Geosynthetics April/May 2022 - 26
Geosynthetics April/May 2022 - 27
Geosynthetics April/May 2022 - 28
Geosynthetics April/May 2022 - 29
Geosynthetics April/May 2022 - 30
Geosynthetics April/May 2022 - 31
Geosynthetics April/May 2022 - 32
Geosynthetics April/May 2022 - 33
Geosynthetics April/May 2022 - 34
Geosynthetics April/May 2022 - 35
Geosynthetics April/May 2022 - 36
Geosynthetics April/May 2022 - 37
Geosynthetics April/May 2022 - 38
Geosynthetics April/May 2022 - 39
Geosynthetics April/May 2022 - 40
Geosynthetics April/May 2022 - 41
Geosynthetics April/May 2022 - 42
Geosynthetics April/May 2022 - 43
Geosynthetics April/May 2022 - 44
Geosynthetics April/May 2022 - Cover3
Geosynthetics April/May 2022 - Cover4
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/0820GS
https://www.nxtbook.com/ifai/geosynthetics/0620GS
https://www.nxtbook.com/ifai/geosynthetics/0420GS
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https://www.nxtbook.com/ifai/geosynthetics/1219GS
https://www.nxtbook.com/ifai/geosynthetics/1019GS
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https://www.nxtbook.com/ifai/geosynthetics/0619GS
https://www.nxtbook.com/ifai/geosynthetics/0419GS
https://www.nxtbook.com/ifai/geosynthetics/0219GS
https://www.nxtbook.com/ifai/geosynthetics/1218GS
https://www.nxtbook.com/ifai/geosynthetics/1018GS
https://www.nxtbook.com/ifai/geosynthetics/0818GS
https://www.nxtbook.com/ifai/geosynthetics/0618GS
https://www.nxtbook.com/ifai/geosynthetics/0418GS
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