SSC JE Civil Engineering 29-Oct-2020 Shift 1 Paper

Soil mass is generally a three phase system as it contains soils solids at bottom along with water in middle and air at top. The space covered by water and air in the soils mass is called voids. The water and air contents are changed by changes in conditions and location: soils can be perfectly dry (have no water content) or be fully saturated (have no air content) or be partly saturated (with both air and water present). ${\mathrm{V}}_{\mathrm{air}}=$ Volume of air voids
${\mathrm{V}}_{\mathrm{w}}=$ Volume of water
${\mathrm{V}}_{\mathrm{s}}=$ Volume of solids
${\mathrm{W}}_{\mathrm{air}}=$ mass of air which is assumed to be zero
${\mathrm{W}}_{\mathrm{w}}=$ mass of water
${\mathrm{W}}_{\mathrm{s}}=$ Mass of soil solids.