Correct Answer - Option 4 : none of these
Concept:
Permeability depends on both soil properties and Fluid properties
The kozney – Carman equation is quite useful, it reflects the effect of factors that affect permeability
\(k = \frac{{{\gamma _w}}}{\mu } \times \frac{{{e^3}}}{{1 + e}} \times D_{10}^2\)
Where,
D10 is effective grain size
e is the void ratio
μ is viscosity, γ w is the unit weight of water
a) Grain size: The coefficient of permeability includes D102, where D10 is a measure of grain size
If the void ratio is the same then permeability is more in coarse soil than in the fine soil
b) Void ratio: From the equation, it is clear that k ∝ e2
If the particle size is the same, then loose soils are more permeable than dense soils
c) Degree of saturation: Permeability is directly proportional to the degree of saturation
d) Particle shape: It is expressed in terms of specific surface area and permeability relates to the specific surface area as ‘k ∝ 1/S2 ‘.
Explanation:
From kozney – Carman equation,
\(k = \frac{{{\gamma _w}}}{\mu } \times \frac{{{e^3}}}{{1 + e}} \times D_{10}^2\)
\(k \propto \frac{1}{1\ +\ e}\)
If the permeability of soil at the void ratios e1 and e2 is k1 and k2
Then, \(\frac{k_1}{k_2} \ = \frac{1\ +\ e_2}{1\ +\ e_1}\)
