Question

Consider the following statements regarding permeability of soils:
1. Permeability of coarse grained soil is inversely proportional to the specific surface at a given porosity.
2. Direct measurement of permeability of a soil specimen at any stage of loading in odometer test can be made only in fixed-ring type oedometer.
3. The permeability of an aquifer increased with decreases in temperature of water moving through it.
Which of the above statements is/are correct?

• A. 1 and 2
• B. 1 and 3
• C. 2 and 3
• D. 1, 2 and 3

Answer 1

The correct option is A 1 and 2

(a)
As per Kozney-Carman equation

$k=\left(\frac{\gamma }{\mu }\right)\frac{e^3}{1+e}\times \frac{1}{S_s^2}$

$k\propto \frac{1}{S_s^2}$

Dynamic viscosity (μ) is inversely proportional to temperature hence permeability is directly proportional to the temperature.
In consolidation test, two types of consolidation cell, the floating ring cell and the fixed ring cell are commonly used. A falling head permeability test can be performed on the consolidation specimen attaching a stand pipe to fixed ring consolidometer, hence the coefficient of permeability can be determined only in fixed ring test.