How to Determine Dry Unit Weight and Porosity of a Soil?

[KAISER91]

Help With Soil Questions...

Homework Statement

Any help will be appreciated.

The moist weight of a soil is 16.5 kN/m^3. Given w = 15% and Gs = 2.67
determine;

(a) dry unit weight
(b) porosity
(c) degree of saturation
(d) mass of water, in kg/m3, to be added to reach full saturation

Answers are;
[14.35 kN/m3, 0.452, 48.5%, 233 kg/m3]

Homework Equations

Note that γ = gamma

The Attempt at a Solution

Here is my attempt at solutions, I'm having trouble with the last 2 questions.

a) dry unit weight

Gs = 2.67
γw = unit weight of water = 9.81
e = 0.826

yd = (Gs * γw * 1) / (1 + e)
γd = (2.67*9.81*1) / 1 + 0.826

= 14.35 kN/m^3
b) Porosityn = e / 1+ e
n = 0.826 / 1 + 0.826
n = 0.452

c) degree of saturation?
d) mass of water, in kg/m3, to be added to reach full saturation
?
Help will be appreciated, thanks.

 

[loobot]

For part c) use the formula se=wG and then multiply your answer by 100%. You should get the correct answer.