Soil is an unconsolidated material which consists of solid, air, water.

Dry soil consists of solid+air

saturated soil consists of solid+water

Partially soil consists of solid+air+water


  1. WATER CONTENT:In soil water can be present in following form

Gravitational water: free water that moves through the soil due to the force of gravity.

Capillary water: Water in the micropores, the soil solution.

Hygroscopic water: This water forms very thin films around soil particles and is not available to the plant. The water is held so tightly by the soil that it can not be taken up by roots.

It is the ratio of weight of water to the weight of solid

2. DEGREE OF SATURATION: Degree of saturation volume of water to the volume of voids in soil( here volume of voids is the volume of water+volume of air)

for dry condition degree of saturation is zero because the value volume of water is zero.

for saturated condition the degree of saturation is one because the volume of water will be equal to volume of voids.

3. VOID RATIO: Void ratio is ratio of volume of voids to volume of solid.

void should always greater than zero.

4. POROSITY: Porosity is the ratio of volume of voids to the volume of soil.

5.UNIT WEIGHT: Unit weight is the ratio of weight to the volume.