Environmental Engineering Reference
In-Depth Information
Table 9.13.
Methods for designing geotextiles as filters.
L
OUDIERE
et al. (1982)
For non cohesive soils:
Uniformity coefficient (D
60B
/D
10B
)
4
D
95B
Uniformity coefficient
O
95
4
0.8D
50B
For cohesive soils:
Uniformity coefficient
O
95
4
O
95
D
85B
and
0.05 mm
Uniformity coefficient
O
95
4
O
95
0.8D
50B
and
0.05 mm
AASHTO (
FROM
K
OERNER
, 1986)
For coarse grained soils
,
O
95
50%, passing 0.075 mm
0.6 mm
For fine grained soils
,
O
95
50%, passing 0.075 mm
0.3 mm
(Note: Koerner quotes
O
95
not
for these relationships, which appears to be in error)
C
ARROLL
(1983)
O
95
(2 or 3) D
85B
G
IROUD
(1982) (
for needle punched and woven geotextiles
)
Relative density
1
C
u
3
C
u
3
Loose (RD
35%)
O
95
(C
u
) D
50B
O
95
9D
50B
/C
u
Medium (RD 35% to 65%)
O
95
1.5 (C
u
) D
50B
O
95
13.5D
50B
/C
u
Dense (RD
65%)
O
95
2 (C
u
) D
50B
O
95
18D
50B
/C
u
For woven and heat bonded non wovens
1
C
u
3
O
95
(C
u
) D
50B
C
u
3
O
95
9D
50B
/C
u
where C
u
D
60B
/D
10B
G
IROUD
(1996) indicates Giroud (1982) still applicable
H
EERTEN
(1984)
For cohesionless soils
:
Static load conditions, C
u
uniformity coefficient
5
O
98
10D
50B
, and
D
90B
Static load conditions, C
u
O
98
5
O
98
2.5D
50B
, and
D
90B
Dynamic load conditions (high turbulence, wave action or “pumping”)
O
98
O
98
D
50B
For cohesive soils:
O
98
10D
50B
, and
O
98
D
90B
, and
0.1 mm
H
EERTEN
(1993)
O
90
,
w
O
98
D
90B
, and
D
50B
where O
90
,
w
is obtained by wet sieving
F
ISCHER
, C
HRISTOPHER AND
H
OLTZ
(1990)
O
50
O
90
,
w
}
0.8 D
85B
depending on the geotextile pore size
O
50
1.8 to 7.0D
15B
distribution, and C
u
of soil.
O
50
0.8 to 2.0D
50B
