Correct Answer - Option 4 : 19.44 KN/m
3
Concepts:
The relation between dry density, bulk density and water content is given as:
\(\gamma_d = \dfrac{\gamma_b}{1 +w}\)
Where symbols have the usual meaning
Calculations:
Given: γb = 21 kN/m3; w = 8%
Using above relation:
\(\gamma_d = \dfrac{21}{1+0.08}\)
∴ γd = 19.44 kN/m3
Other Important relations: (Symbols have their usual meaning)
1. W × G = S × e
2. \(\gamma_b = \dfrac{(G + Se)\gamma_w}{1 + e}\)
3. \(\gamma_d = \dfrac{G\gamma_w}{1 + e}\)
4. \(\rm porosity, n = \dfrac{e}{ 1 + e} \)
5. \(\gamma_s = \dfrac{(G + e)\gamma_w}{1 + e}\)