Civil Engineering - Soil Mechanics and Foundation Engineering - Discussion

Discussion Forum : Soil Mechanics and Foundation Engineering - Section 3 (Q.No. 15)
15.
If dry density, water density and specific gravity of solids of a given soil sample are 1.6 g/cc, 1.84 g/cc and 2.56 respectively, the porosity of the soil sample, is
0.375
0.370
0.380
0.390
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
30 comments Page 3 of 3.

Doyel said:   8 years ago
Taking value of water density as 1.84 g/cc, answer comes to be 0.67.

Is not this the right answer?

Munshi said:   8 years ago
Just remember that whatever value of water density is given we have to neglect it, density of water is fixed at 1g/cc.

Satendra said:   8 years ago
@Raval Chaitanya.

How water content get .15?

Raval Chaitanya Vajendrakumar said:   9 years ago
The value of water density is given to find the right value of degree of saturation,
As we have found void ratio = 0.6.

We have ,
e * s = w * g,
=> S = (.15 * 2.56)/0.6,
=> S = 64%. Where w = (1.84/1.6)-1.

Anonymous said:   9 years ago
If we have to take the density of water as 1 gm/cc then why 1.84 g/cc is given in question?

In order to get the right answer ignore the value given in question.

Sudarsan Sahoo said:   9 years ago
Then what about the value of water density or what does that signify?

Bhakt said:   9 years ago
Both are right @Rubby and @Reddy.

The void ratio is (e).

N SAMEER GUPTA said:   10 years ago
You calculated void ratio not porosity.

Ruby said:   1 decade ago
1.6 = (1*2.56)/(1+e);
e = 0.6;
n = e/1+e;
n = 0.6/(1+0.6);
Then n = 0.375.

S.Rajashekar Reddy iiit basar said:   1 decade ago
Dry density of soil is = 1.6g/cc.
Specific gravity of soil = 2.56.
Density of water take it as = 1g/cc.

Then use the relation between dry density and void ratio,

i.e,dry density of soil = (specific gravity*density of water)/(1+void ratio).

Here you got void ratio value then use the relation between porosity and void ratio.

Then you will get answer as 0.375.
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