User Manual

Appendix 33
SOIL TEXTURES
OSHA Cohesive Soil Types (A, B, or C) can be identified by the texture of a given soil. Shown below on the left is the U.S.
Department of Agriculture Textural Soil Classification Chart. This chart plots soil classification as a percentage of sand, silt,
and clay and classifies each unique combination. The chart on the right contains the same information with OSHA Cohesive
Soil Types superimposed.
In summary, understanding the soils at a given jobsite is the key to determining the effectiveness of digging with the Utility AirSpade.
A
A
A
A
AB
AB
BC
B
B
C
C
C
10
20
30
40
50
60
70
80
90
100
10
20
30
40
50
60
70
80
90
OSHA Cohesive Soil Types
100
90
80
70
60
50
40
30
20
10
100
PERCENT SILT
PERCENT SAND
PERCENT CLAY
USDA Textural Soil Classifications
10
20
30
40
50
60
70
80
90
100
10
20
30
40
50
60
70
80
90
PERCENT CLAY
PERCENT SILT
100
90 80
70
60
50
40
30 20
10
100
PERCENT SAND
SAND
SILT
LOAMY
SAND
SAND LOAM
SILT LOAM
LOAM
CLAY LOAM
SILTY
CLAY LOAM
SANDY
CLAY LOAM
SANDY
CLAY
SILTY
CLAY
CLAY