Determining Dry Density Of Soil By Core Cutter Mrthod

Intrduction:

Cylindrical core cutter is a seamless tube which is pressed into soil so that it gets filled with soil sample. The volume of tube is known; the mass of soil is calculated. Dry density of soil is obtained as

                    ρ= α/1+w

                    α=M/V

         M= mass of soil

         V =volume of soil sample=volume of core cutter

        W= water content in soil

Equipment:

Cylindrical core cutter of 100 mm diameter and 130 mm long

Steel rammer of about 9 kg.

Steel dolly, 25 mm high and 100mm internal diameter.

Weighing balance of accuracy up to 1g.

Palatte knife, straight edge etc

Procedure

Measure internal diameter of core cutter and calculate its volume.

Determine the mass of cutter (M₁) up to nearest gram.

Expose small area on ground up to 300mm.

Place the dolley over core cutter and press the cutter in ground by hitting it by rammer.

Stop pressing when about 15 mm of dolley protrudes over the soil surface.

Remove the soil around the cutter; trim the top of soil projecting sample from cutter.

weight the cutter  with soil sample (M₂) up to nearest gram.

Remove the sample from cutter; take out small amount of sample for water content determination.

Observations:

ρ= α/1+w

α=M/V

α=wet density of soil

V =volume of soil sample=volume of core cutter

W= water content in soil

Mass of empty core cutter=M₁

Mass of core cutter + soil sample =M₂

M= mass of soil = M₂- M₁

Conclusion:

Core cutter method is good enough to finding out the dry density of soil direct at site.

This is more practical and does not need much equipments

It’s fast and reliable.