# How is specific gravity used in soil mechanics?

## How is specific gravity used in soil mechanics?

The specific gravity (GS) of a soil refers to the ratio of the solid particles’ unit weight to the unit weight of water. GS is a significant parameter of soil mechanics since it can be associated with the soil’s mineral composition and weathering.

## How do you measure specific gravity of soil?

Now that you have the density of soil solids, you can calculate the specific gravity of soil solids (SG). To find it, divide the density of soil solids by the density of water (Pw), which is 1,000 kg/m3. The calculation should then be: SG = Ps/Pw.

**Why is specific gravity test done for soil?**

1 The specific gravity of soil solids is used to calculate the density of the soil solids. This is done by multiplying its specific gravity by the density of water (at proper temperature).

### How do you perform a specific gravity test?

The normal method of determining specific gravity is to weigh the specimen dry (DW), then to suspend the specimen in water on a string, and to measure the weight pulling on the string (WW) (specimen weight suspended in water). Then you subtract WW from DW, and divide the difference into DW.

### How is the specific gravity of soil determined?

Standard Reference: ASTM D 854-00 – Standard Test for Specific Gravity of Soil Solids by Water Pycnometer. Significance: The specific gravity of a soil is used in the phase relationship of air, water, and solids in a given volume of the soil. Equipment: Pycnometer, Balance, Vacuum pump, Funnel, Spoon. 28

**What is the specific gravity of distilled water?**

Specific gravity is the ratio of the mass of unit volume of soil at a stated temperature to the mass of the same volume of gas-free distilled water at a stated temperature. Standard Reference: ASTM D 854-00 – Standard Test for Specific Gravity of Soil Solids by Water Pycnometer. Significance:

## When to use spec IFIC gravity of solids?

The spec ific gravity of solids is normally only applied to that fraction of a soil that passes the No. 4 sieve. Generally, geotechnical engineers need the soil’s specific gravity to perform additional testing of that soil. In these cases there may be a different soil fraction used when performing this test.

## Which is the correct definition of specific gravity?

Thus specific gravity, Gs, is defined as Gs = unit weight (or density) of soil solids only / unit weight (or density) or water where W s = mass of soil solids (g); V s = volume of soil solids (cm 3 ); and p w = density of water (g/cm 3)