|
Group
Symbol
|
* if gravelly
** erosion critical
*** volume change critical
- not appropriate for this type of
use
Soil Type |
Relative Desirability for
Various Uses
(1=best; 14=least desirability) |
|
Rolled Earth Fill Dams |
Canal Sections |
Foundations |
Roadways |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
GW |
Well-graded gravels,
gravel/ sand mixes, little or no fines |
- |
- |
1 |
1 |
- |
- |
1 |
1 |
1 |
3 |
GP
sand |
Poorly-graded gravels,
gravel/ mixtures, little or no fines |
- |
- |
2 |
2 |
- |
- |
3 |
3 |
3 |
- |
| GM |
Silty gravels,
poorly-graded gravel/sand/silt mixtures |
2 |
4 |
- |
4 |
4 |
1 |
4 |
4 |
9 |
5 |
| GC |
Clay-like gravels, poorly
graded gravel/sand/clay mixtures |
1 |
1 |
- |
3 |
1 |
2 |
6 |
5 |
5 |
1 |
 |
SW |
Well-graded sands,
gravelly
sands, little or no fines |
- |
- |
3* |
6 |
- |
- |
2 |
2 |
2 |
4 |
| SP |
Poorly-graded sands,
gravelly sands, little or no fines |
- |
- |
4* |
7* |
- |
- |
5 |
6 |
4 |
- |
| SM |
Silty sands, poorly-graded
sand/ silt mixtures |
4 |
5 |
- |
8* |
5** |
3 |
7 |
6 |
10 |
6 |
| SC |
Clay-like sands,
poorly-graded sand/clay mixtures |
3 |
2 |
- |
5 |
2 |
4 |
8 |
7 |
6 |
2 |
 |
 |
ML |
Inorganic silts and very
fine sands, rock flour, silty or clay-like fine sands with slight plasticity |
6 |
6 |
- |
- |
6** |
6 |
9 |
10 |
11 |
- |
| CL |
Inorganic clays of low to
medium
plasticity, gravelly clays, sandy
clays, silty clays, lean clays |
5 |
3 |
- |
9 |
3 |
5 |
10 |
9 |
7 |
7 |
| OL |
Organic silts and organic
silt-clays of low plasticity |
8 |
8 |
- |
- |
7** |
7 |
11 |
11 |
12 |
- |
 |
MN |
Organic silts, micaceous
or diatomaceous fine sandy or silty soils, elastic silts |
9 |
9 |
- |
- |
- |
8 |
12 |
12 |
13 |
- |
| CH |
Inorganic clays of high
plasticity, fat clays |
7 |
7 |
- |
10 |
8** |
9 |
13 |
13 |
8 |
- |
| OH |
Organic clays of medium
high plasticity |
10 |
10 |
- |
- |
- |
10 |
14 |
14 |
14 |
- |