SAND REPLACEMENT TEST Sawanpreet Singh Anoop Singh Engineering Soil Testing
Nov 22, 2014
SAND REPLACEMENT
TESTSawanpreet SinghAnoop Singh
Engineering Soil Testing
Objectives
Density of soil.
Bulk density of soil. Dry density of soil. Water content. Void ratio. Degree of saturation.
Applications
Stress in soil - due to overburden pressure. Bearing capacity of soil. Settlement of footings. Earth Pressure behind retaining wall, dam,
embankments. Stability of natural slopes, dams, embankments. Field Compaction of soil. Permeability. Relative density. Void ratio, porosity, degree of saturation.
Basics Density is mass per unit volume. Density : Mass
Volume
For same volume: Cotton Steel Less mass, less density More mass,
more density
Principle
Density = Mass/Volume
For sand,
Volume : known (calibrating cylinder)Mass : known (mass of sand in calibrating
cylinder)
Density can be calculated.
Principle
Volume = Mass/Density
For Soil,
Mass : known (mass of sand in hole)Density : known (calculated earlier)
Volume of hole can be calculated.
Principle
Density = Mass/Volume
For Soil,
Mass : known (mass of excavated soil)Volume known (calculated earlier)
Density can be calculated.
Principle
Density(soil) = Mass(soil) Volume(hole)
Volume(hole) = Mass(sand) Density(sand)
Density(sand) = Mass(sand) Volume(cylinder)
Density(soil) = Mass(soil) Volume(hole)
Volume(hole) = Mass(sand) Density(sand)
Density(sand) = Mass(sand) Volume(cylinder)
Apparatus
Sand pouring cylinder Trowel or bent spoon Cylindrical calibrating container Metal tray with hole Sand – clean oven dried, passing through 600
micron sieve Weighing balance Glass plate
Sand Pouring Cylinder
Cylindrical calibrating cylinder
100 mm diameter, 150 mm height
Metal tray with hole
300 mm square,
40 mm deep,
with a hole of
100 mm diameter
in centre
Procedure
Calibration of apparatus
Measurement of soil density
Calibration
Step 1
Measure internal volume of calibrating container from volume of water required to fill the container.
Calibration
Step 2
Fill the pouring cylinder with sand within about 1cm of top and weigh it.
Step 3
Place the pouring cylinder concentrically on the top of calibrating cylinder.
Calibration
Step 4
Open the shutter to allow the sand to run out and fill the container.
Step 5
When there is no further movement of sand in the pouring cylinder, close the shutter.
Remove the cylinder and weigh it.
Calibration
Step 6
Place the pouring cylinder on a place surface such as glass plate.
Step 7
Open the shutter to allow the sand to run out.
When there is no further movement of sand in the pouring cylinder, close the shutter.
Remove the cylinder and weigh it.
Measurement of Soil Density
Step 1
Fill the pouring cylinder with sand within about 1cm of top and weigh it.
Step 2
Clean and level the ground where the field density is required.
Measurement of Soil Density Step 3
Place the metal tray with the central hole over the portion of soil to be tested.
Step 4
Excavate the soil approximately 10 cm diameter as of hole in tray and 15 cm deep.
This volume will be approximately same as that of calibrating container.
Measurement of Soil Density
Step 5
Collect the excavated soil in metal tray and weigh it.
Step 6
Water content of excavated soil can be determined later on by drying the excavated soil and weighing it.
Measurement of Soil Density
Determination of Water Content :
mass of water = mass of wet soil – mass of dry soil
water content, W = mass of water X 100 mass of dry soil
Measurement of Soil Density Step 7
Place the pouring cylinder over the hole so that base of cylinder covers the hole concentrically.
Step 8
Open the shutter to allow the sand to run out into the hole.
When there is no further movement of sand, close the shutter.
Remove the cylinder and weigh it.
Precautions
If for any reason, depth of excavation is changed, calibrating cylinder of comparative depth should be used.
Hole should not be enlarged by levering the digger against the side of the hole.
No loose material should be left in the hoe. Initial height of sand should be kept same
during calibration and measurement. There should be no vibrations during the test. Since dry density of soil varies from place to
place, repeat the test at several points and take average.
Observations and Calculations
Observations and Calculations
Observations and Calculations
Observations and Calculations
Result