TM 5-818-8/AFJMAN 32-1030
= remolded shear strength of foundation
materials
= (20)(102)
= 2,040 pounds per inch width
(2) Geotextile fill and seam tensile modulus of
10 percent elongation:
(2) Rotational slope stability analysis:
= 20 T
= (20)(T = 233 pounds per inch width)
= 4,670 pounds per inch width
i. Summary of Minimum Geotextile Require-
h. Tensile Seam Strength and Fill Require-
ments. If the geotextile chosen is a woven polyes-
ments. Determine geotextile tensile strength re-
ter yarn and only 50 percent of the ultimate
quirements in geotextile till (cross machine direc-
geotextile load is used, then the minimum ulti-
tion) and across seams. Tensile strength
mate strength is 2 times the required working
requirement in this direction depends on the
tensile strength 233, or 466 ponds per inch width
amount of squeezing out and dragging loads on the
to compensate for possible creep.
(1) Soil-geotextile friction angle,
equals
underside of the geotextile and the amount of
3.9 degrees.
shoving or sliding that the 2 to 3 feet of sand fill
(2) Ultimate tensile strength
in the geo-
material causes during initial placement. If three
textile warp directions working tensile strength
panels 16 feet wide are in place and the founda-
equals 466 pounds per inch width.
tion material moves longitudinally along the em-
(3) Ultimate tensile strength
in the geo-
bankment alignment because of construction activ-
textile fill and cross seams directions equals to 300
ities when establishing a working platform, then
pounds per inch width.
the loads in the geotextile fill direction can be
(4) Tensile modulus (slope of line drawn
calculated as follows:
through zero load and strain and trough load at 5
(1) Geotextile fill and seam tensile strength
percent elongation) at 5 percent geotextile elonga-
requirement:
tion in geotextile warp direction is 4,670 pounds
= (3 panels) (l6 feet wide)
per inch width, (based on working tensile strength)
and 10 percent geotextile elongation in the fill and
where
cross seam directions is 3,000 pounds per inch
= (3)(16 feet) (50 pounds per square
width.
foot.)
(5) Contractor survivability and constructabi-
= 2,400 pounds per foot width
lity requirements are included in tables 2-3, 2-4
= 200 pounds per inch width
and 2-5. Geotextile specifications must meet or
at FS of 1.5 = 300 pounds per inch
exceed these requirements.
width
4-10
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