Question

During the consolidation of a clay layer, if instead of double drainage, the drainage is allowed at single face only. the rate of compression will be

• A. 4 times slower
• B. 4 times faster
• C. 2 times slower
• D. 2 times faster

Answer 1

The correct option is A 4 times slower

From Taylor's formula, we have

$T_v=\frac{C_{v}t}{d^2}$

$\Rightarrow t\propto d^2$

$\Rightarrow \frac{t_d}{t_s}={\left(\frac{d_d}{d_s}\right)}^2={\left(\frac{H/2}{H}\right)}^2$

$\Rightarrow t_s=4t_d$

Thus the time taken by the clay in single drainage is four times more than in double drainage.