Question

An upward hydraulic gradient i of a certain magnitude will initiate the phenomenon of boiling in granular soils. The magnitude of this gradient is

• A. $0\le i\le 0.5$
• B. $0.5\le i\le 1.0$
• C. $i\simeq 1.0$
• D. $1<i\le 2$

Answer 1

The correct option is C $i\simeq 1.0$

Critical hydraulic gradient, $i_{cr}=\frac{G-1}{1+e}$

$G=2.65,e=0.7$

So on solving $i_{cr}\simeq 1$