Question

For a given soil if Gs=2.74, moist unit weight =132.3pcf, and water content=16.6\%. Determine dry unit weight, void ratio, porosity, degree of saturation.

Answer 1

1. Dry Unit Weight:
Dry unit weight (γ_d) = γ - γ_w
Given:
Moist unit weight (γ) = 132.3 pcf
Unit weight of water (γ_w) = 62.4 pcf

Dry unit weight (γ_d) = 132.3 - 62.4

2. Void Ratio:
Void ratio (e) = (1 + (w/Gs)) * (1 - S)
Given:
Water content (w) = 16.6%
Specific gravity of solids (Gs) = 2.74

Void ratio (e) = (1 + (0.166/2.74)) * (1 - S)

3. Porosity:
Porosity (n) = e / (1 + e)
4. Degree of Saturation:
Degree of saturation (S) = (Vw / Vv) * 100
Given:
Water content (w) = 16.6%
Moist unit weight (γ) = 132.3 pcf
Unit weight of water (γ_w) = 62.4 pcf

Vw = (w / 100) * γ / γ_w
Vv = Vw / (1 + e)

S = (Vw / Vv) * 100

By substituting the given values into the equations, you can simplify and calculate the dry unit weight, void ratio, porosity, and degree of saturation.