Question

Which one of the following equations correctly gives the relationship between the specific gravity of soil grains ( G) and the hydraulic gradient (i) to initiate 'quick' condition in a sand having a void ratio of 0.5?

• A. G = 0.5i + 1
• B. G = i + 0.5
• C. G = 1.5i + 1
• D. G = 1.5i - 1

Answer 1

The correct option is C G = 1.5i + 1

Critical hydraulic gradient,

$i_{cr}=\frac{G-1}{1+e}=\frac{G-1}{1+0.5}$

$\therefore$ $G=1.5i+1$