NY/T 1121.1-2006 Soil Testing Part 4: Determination of Soil Bulk Density

1 Scope of application

This section applies to the determination of bulk density of various soils except hard and brittle soil.

2 Measurement principle

Use a ring knife with a certain volume to cut the soil sample in its natural state, fill it with the soil sample, and calculate the mass of the dried soil sample per unit volume after weighing, which is the bulk densit.

3 Main instruments and equipment

1 Ring knife (volume 100 cm ³ )

2 Steel ring knife holder

There are two small vent holes on i.

3 Soil cutter

The blade should be straight

4 Small shovel

5 Wooden hammer

6 Balance (sensitivity 1 g)

7 Electric heating constant temperature drying oven

8 Dryer

4 Analysis steps

Before sampling, evenly coat the inner wall of each ring knife with a thin layer of vaseline, and weigh the weight of the ring knife (m ₁ ) one by one, accurate to 1 .

5 Result calculation

where:

m ₂ — the mass of the ring knife and wet soil, in grams (g);

m ₁ — the mass of the ring knife, in grams (g);

V—the volume of the ring knife, in cubic centimeters (cm ³ ), V = π r² h , where r is the inner radius of the edge of the ring knife (cm), and h is the height of the ring knife;

W - soil water content, in grams per kilogram (g/kg.

The measurement results are expressed as the arithmetic mean, with two decimal place.

6 Precision

Parallel determination results allow the absolute difference ≤ 02 g / cm ³

7 Notes

For the determination of bulk density, the ring knife filled with soil samples can also be directly dried in a constant temperature drying oven at 105°C ± 2°C to a constant weight, and then weighed on a 1% precision balanc.