Question

The relationship between the specific gravity of sand (G) and the hydraulic gradient (i) to initiate quick condition in the sand layer having porosity of 30% is

• A. G = 0.7i +1
• B. G = 1.43i -1
• C. G = 1.43i + 1
• D. G = 0.7i - 1

Answer 1

The correct option is C G = 1.43i + 1

$e=\frac{n}{1-n}=\frac{0.3}{0.7}=\frac{3}{7}$

$\frac{G-1}{1+e}=i$

$G-1=i(1+\frac{3}{7})$

$\Rightarrow G=1.43i+1$ (Ans.)