Question

Soil having bulk density of 2.15mg/cm³ and water content 12% . G-2.65 Calculate dry density ,void ratio, degree of saturation and air content​

Answer 1

Given : -

Bulk density (γ₀) = 2.15 g/cm³

water content (ω) = 12% = 0.12

Specific gravity (G) = 2.65

Need to find : -

Dry density (γ$_{d}$) , Void ratio (e)  , degree of saturation (s) , air content ($a_{c}$)

Solution : -

(i)  we have realtionship between dry density and bulk density as,

⇒ γ₀  =  γ$_{d}$ / ( 1 + ω )

⇒   γ$_{d}$  = 2.15 x ( 1 + 0.12 )

∴  γ$_{d}$  = 2.41 g/cm³

Also have ,

⇒ s  x e = G x ω

⇒ s x e = 2.65 x 0.12  

⇒ s  x e = 0.318  ____(1)

(ii)   And,

⇒ γ₀  $= \frac{G+se}{1 + e}$ x γ$_{w}$

⇒ 1 + e = [G + se) / γ₀] x γ$_{w}$

[∵ from equation (1) we have , s x e = 0.318) ]

⇒ e = [(2.65 + 0.318) / 2.15] x 1 - 1  

∴ e = 0.38.

(iii)  Now, s  x e = 0.318

⇒ s x 0.38 = 0.318

∴ s = 0.8368 (or) 83.68%

(iv) We know,

⇒ s + $a_{c}$ = 1

⇒ $a_{c}$ = 1 - 0.8368

∴  $a_{c}$ = 0.1632 (or) 16.32%