In its natural condition, a soil sample has a mass of 1.980

In its natural condition, a soil sample has a mass of 1.980 kg and a volume of 0.001 m³. After being completely dried in an oven, the mass of the sample is 1.800 kg. Specific gravity G is 2.7. Unit weight of water is 10 kN/m³

Let degree of saturation can be represented by ‘S_r ’ of a soil in natural condition.

γ =	W	=	1.980 × 9.81	= 19.42 kN/m³
	V		0.001

γ_d =	W_d	=	1.800 × 9.81	= 17.658 kN/m³
	V		0.001

γ_d =	G.γ_w
	1 + I

where G = 2.7 given
γ_w = 9.81 KN/m³

∴ 17.658 =	2.7 × 9.81
	1 + I

Voide ratio,

I =	2.7 × 9.81	- 1
	17.658

I = 1.5 – 1 = 0.5
I = 0.5
In natural condition,

γ =	γ_w(G + I.S_r)
	1 + I

Here, only S_r is known

19.42 =	9.81(2.7 + 0.5 × S_r)
	1 + 0.5

29.13 = 9.81 (2.7 + 0.5 × S_r)
2.969 – 2.7 = 0.5 × S_r
S_r = 0.5388
∵ Degree of saturation Sr = 0.54