Tool: Soil Types – Canada and United States Soil Types
The type of soil determines the strength and stability of trench walls. In most Canadian Provinces, soil types fall into four categories.
Canadian Soil Classifications |
|
| Type | Description |
| Type 1 | This type of soil is so hard that it is close to rock. |
| Type 2 | Easily excavated with a backhoe, remains intact for short time only – i.e. silty clay |
| Type 3 | Previously excavated, flows through fingers – i.e. sand |
| Type 4 | High moisture content, sensitive to vibration – i.e. quicksand, clay |
In the U.S. there are also four types of soil, but the naming convention is different.
U.S. Soil Classifications |
|
| Type | Description |
| Stable Rock | The natural solid mineral matter can be excavated with vertical sides and remain intact while exposed. |
| Type A | Cohesive soils. i.e. clay, silty clay, sandy clay, clay loam |
| Type B | Cohesive soils but less than Type A – i.e. angular gravel; silt/silt loam; previously excavated |
| Type C | Cohesive soils but less than Type A/B – i.e. gravel, sand and loamy sand, submerged soil, soil w/ freely seeping water, unstable submerged rock |