Question

A one-dimensional consolidation test is carried out on a standard 19 mm thick clay sample. The oedometer's deflection gauge indicates a reading of 2.1 mm, just before removal of the load, without allowing any swelling. The void ratio is 0.62 at this stage. The initial void ratio (round off to two decimal places) of the standard specimen is

• A. 0.82

Answer 1

The correct option is A 0.82
Oedometer test has one dimensional consolidation. Hence, settlement of clay layer is given as,

$\frac{\Delta H}{H}=\frac{\Delta e}{1+e_o}$

$[\Delta e=e_o-e_t]$

$\frac{2.1}{19}=\frac{e_o-0.62}{1+e_o}$

$\Rightarrow 0.1105+0.1105e_o=e_o-0.62$

$\Rightarrow e_o=0.82$