Question

The relation between difference in thickness and voids ratio is given by ___________

(a) \(∆H = \frac{e_o-e}{1+e_o}\)

(b) \(\frac{∆H}{H_0} =\frac{e_o-e}{1+e_o}\)

(c) \(H_0 = \frac{e_o-e}{1+e_o}\)

(d) \(\frac{∆H}{H_0} = \frac{1}{1+e_o}\)

I got this question in an interview for internship.

This interesting question is from Consolidation Process in chapter One Dimensional Consolidation of Geotechnical Engineering I

Answer 1

Right choice is (b) \(\frac{∆H}{H_0} =\frac{e_o-e}{1+e_o}\)

The best explanation: When the soil is laterally confined, there is decrease in the volume. Since the soil is laterally confined, there will be change of volume only due to the decrease in the thickness which implies to the changes in volume is proportional to change in thickness ∆H. This is also true for the initial conditions.

 ∴  \(\frac{∆H}{H_0} = \frac{e_o-e}{1+e_o}\)

Where eo-e=∆e.