WORLD FOR CIVIL

Physical Properties Of Soils

The soil properties and parameters can be broadly classified as

1)Physical
2)Engineering
3)Index

Physical soil properties include density, particle size and distribution, specific gravity, and water content.
The water content w of a soil sample represents the weight of free water contained in the sample expressed as a percentage of its dry weight.
The degree of saturation S of the sample is the ratio, expressed as percentage, of the volume of free water contained in a sample to its total volume of voids V_v
Porosity n, which is a measure of the relative amount of voids, is the ratio of void volume to the total volume V of soil:

n=V_v/V

The ratio of V_v to the volume occupied by the soil particles V_s defines the void ratio e. Using this e we can calculate the degee of saturation by

S=wG_s/e

where G_s represents the specific gravity of the soil particles. For most inorganic soils, G_s is usually in the range of (2.67+ or -0.05.)
The dry unit weight ?_d of a soil specimen with any degree of saturation may be calculated from

?_d=?_wG_sS/(1+wG_s)

where w =unit weight of water and is usually taken as 62.4 lb/ft³ (1001 kg/m³ ) for freshwater and 64.0 lb/ft³
(1026.7 kg/m³ ) for seawater.