Answer
given,
Volume of Depression, V = 75000 m³
borrow soil
Density of soil,γ = 1540 Kg/m³
water content,w = 8 % = 0.08
Specific gravity of solid,G = 2.66
Final in-place
dry density = 1790 kg/m³
water content = 13 % = 0.13
a) Volume of borrow soil require to fill the depression
Mass of solid solid,m= dry density of inplace soil x Volume of depression
= 1790 x 75000
m = 1.3425 x 10⁸ Kg
dry density of the borrow pit
[tex]\gamma_d = \dfrac{\gamma}{1 + w}[/tex]
[tex]\gamma_d = \dfrac{1540}{1 + 0.08}[/tex]
[tex]\gamma_d = 1425.93\ kg/m^3[/tex]
Volume of borrow soil required
[tex]V = \dfrac{m}{\gamma_d}[/tex]
[tex]V = \dfrac{1.3425\times 10^8}{1425.93}[/tex]
V = 94149 m³
b) Water required
[tex]W = 1790\times 75000\times 0.13 - 1425.93\times 94149\times 0.08[/tex]
W = 6.71 x 10⁶ Kg
Water required to achieve 13% moisture is equal to W = 6.71 x 10⁶ Kg