1. In Place Soil Density Test Methods
TDP 2 - Soils Eng.
Soil Density Test

2. Unit Weight or Density
Unit weight () or density is defined as the weight per unit volume of a soil.
The total unit weight includes the weight of soil solids and water divided by the total volume.
 = unit weight
Ws= weight of solids
Ww = weight of water
V = total volume
W = total weight
TDP 2 - Soils Eng.
Soil Density Test

3. In Place Soil Density and Unit Weight Field Test Methods
Sand Cone Method
Drive Cylinder Method
TDP 2 - Soils Eng.
Soil Density Test

4. In Place Soil Density Sand Cone Method – ASTM D 1556
Test hole is hand excavated (approx. 6” diameter)
Material is saved in a container, weighed, and water content calculated
Hole is filled with free flowing sand of known density and volume is determined
In place wet density is determined by dividing wet weight by volume of hole
By knowing water content and wet density, the in-place dry density is calculated
sand
Hand Excavated Hole
TDP 2 - Soils Eng.
Soil Density Test

5. In Place Soil Density Drive Cylinder Method
1) Determine: Weight of cylinder in grams
Weight of cylinder in in3
 2) Drive cylinder and remove
 3) Determine weight of cylinder and sample in grams
 4) Remove sample from cylinder
 5) Obtain about 100 grams of soil from center of sample and determine moisture content
 6) The dry weight of the sample is calculated:
  Wd = (w1-w2) x 100
(100 +w)
  w1 = weight of cylinder and sample in grams
w2 = weight of cylinder in grams
w3 = moisture content % of dry weight
w4 = weight in grams
 7) Dry density of sample is calculated:
  Dry Density = Wd V
Wd = dry density
V = Volume of cylinder in cubic feet
TDP 2 - Soils Eng.
Soil Density Test

6. Soil Moisture Check Obtain a sample of soil and weigh it
Dry the soil in microwave until weight does not change
Determine Moisture (w)
w = moisture content (%)
Ww= weight of water
Ws = weight of solids
TDP 2 - Soils Eng.
Soil Density Test

7. Soil Density Reference Indicators
Tile Probes
Shovels
TDP 2 - Soils Eng.
Soil Density Test

8. Class Exercise, Sand Cone and Drive Cylinder Methods
Obtain soil and compact into the boxes
Determine the soil moisture and in place dry density via the sand cone method and drive cylinder methods
Utilizing the proctor chart developed previously to determine the percent maximum density achieved
Use Form ENG-530B for step by step procedure
TDP 2 - Soils Eng.
Soil Density Test