Civil Engineering - Soil Mechanics and Foundation Engineering - Discussion

Discussion Forum : Soil Mechanics and Foundation Engineering - Section 4 (Q.No. 22)
22.
A soil mass coated with a thin layer of paraffin weighs 460 g. When immersed, it displaces 299 cc of water. The weight of paraffin is 10 g. If specific gravity of solids is 2.5 and that of paraffin 0.9, the void ratio of soil, is
0.55
0.60
0.65
0.70
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
8 comments Page 1 of 1.

SAYYAD Wazir said:   3 years ago
Dry unit weight=(G*Unit weight of water)/(1+e),
(460+10)/(299)=(2.5*1)/(1*e),
e = .5923~ 0.6,
e = 60.

So, the correct option is "B"
(4)

Vivek said:   5 years ago
@Jl pio.

In that question, you should go for bulk density.

Then find dry density using bulk and dry density relationship then go for void ratio using a dry density.
(2)

JL Pio said:   5 years ago
Thank you for the explanation but what about if there's additional given water content of 10%?
(1)

Lund chut said:   5 years ago
Thanks for explaining it @Abhay and @Swamy.

Munesh yadav said:   5 years ago
Thanks @Abhay and @Swamy.
(1)

Ruaa said:   7 years ago
Thank you @Abhay.
(1)

Abhay said:   10 years ago
Specific gravity = Weight/(Volume*Density of water).

Volume of Paraffin = Weight/Sp. Gravity => 10/(0.9*1) = 11.11 cc.

Now, volume of soil = (Wt of soil with paraffin coating - Wt. of paraffin)/(Sp. Gravity of soil*Density of water).

Therefore, volume of soil (Vs) = (460-10)/(2.5*1) = 180 cc.

Volume of soil when immersed in water (V) = 299 - 11.11 = 287.89 cc.

V = Vv+Vs => Vv = V-Vs => Vv = 287.89 - 180 = 107.89 cc.

Hence, Void ratio (e) = Vv/Vs = 107.89/180 => e = 0.6.
(12)

CH SWAMY said:   1 decade ago
Parffin volume = 10/(0.9*1.0) = 11.11 cc (1.0 - density of water).

Vol.of Soil = (460-10) /(2.5*1.0) = 180 cc.

Vol.of Soil = 299 -11.11 = 287.89 cc.

Vol.of Voids = 287.89 - 180 = 107.89 cc.

Void Ratio = Vol.Voids / Vol os Soilds = 107.89/180 = 0.60.
(1)

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