Question

The time for 65% consolidation for a 19-mm clay specimen (drained at top and bottom) in the laboratory is 10 minutes. How long will it take for a 4-m thick clay layer in the field to undergo 40% consolidation under the same pressure increment?

Answer 1

456.2 days

Step-by-step explanation:

Cv = tv x d²/t

For v>69%

We have tv = -0.933log(1-0.65)-0.0851

= 0.4254-0.0851

= 0.340

d² = (19/2)²

= 90.25

Cv = 0.340x90.25/10

= 3.0685mm²/min

At 40% consolidation

Tv = pi/4 x 0.4²

= 0.126

t = Tv x d²/cv

= 0.126x(4000)²/3.0685

t = 656998/60*24

= 456.2days

So it is going to take 456.2 days for a 4-m thick clay layer in the field to undergo 40% consolidation under the same pressure increment.