Example $2\mathrm{.}5$: $(i)$ A dry soil has a void ratio of $0\mathrm{.}65$ and its grain specific gravity is $=2\mathrm{.}80.$ What

is its unit weight?

$($ii$)$ Water is added to the sample so that its degree of saturation is $60\%$ without any

change in void ratio. Determine the water content and unit weight.

$($iii$)$ The sample is next placed below water. Determine the true unit weight $($not consid$-$

ering buoyancy$)$ if the degree of saturation is $95\%$ and $100\%$ respectively.