Soil Testing Flashcards
1
Q
Wet Sieving
A
- Seperate fine from coarse grains by washing soil on sieves
2
Q
Dry sieving
A
- Shake through sieves of descending size
- Retained on sieves is weighed and recorded
3
Q
Hydrometer Analysis
A
- Different grain sizes fall through liquids at different velocities
- Grain reaches terminal velocity by stocks law
4
Q
Compaction
A
- Densification of soils by removing air
- Increate strength, stability and reduce frost damage by water removal
5
Q
Variables of compaction
A
1 - Dry density/weight
2- Water content
3 - Compactive effort
4 - Soil type
6
Q
Standard Proctor Test
A
- 2.4kg hammer method
- 300mm drop
- 27 blows/layer
- 3 layers
7
Q
Elevation head (he)
A
Height of a point above a reference point level
8
Q
Total head (h)
A
Water pressure in height of column of water above datum level
9
Q
Coefficient of permeability (k)
A
Discharge velocity of water flow in soil under action of a unit hydraulic gradiant (m/s)
10
Q
Discharge velocity (v)
A
Mean velocity of flow of water related to the cross-sectional area which it flows
11
Q
Hydraulic gradient (i)
A
- Ratio of the difference in total head on either side of a soil layer
- To thickness of layer measured in direction of flow
12
Q
Shear Strength of Soil
A
- When max strength is reach soil fails
- Particles either roll along each other (up and down along the direction) or slide flat along the top
13
Q
Importance of Shear Strength
A
- When building upon it need to know limitations
14
Q
Factors Affecting Shear Strength
A
- Frictions and cohesion (interlocking and bonding)
- Soil compaction
- Inital state
- Structure
15
Q
Shear Strength Testing
A
- Direct shear test
- Triaxial test
