Question

In a direct shear test, the shear stress and normal stress on a dry sand sample at failure are $0.6kg/c{m}^2$ and $1kg/c{m}^2$ respectively. The angle of internal friction of the sand will be nearly.

• A. ${25}^o$
• B. ${31}^o$
• C. ${37}^o$
• D. ${43}^o$

Answer 1

The correct option is B ${31}^o$

$\tau =\sigma tan\Phi ;tan\Phi =\frac{0.6}{1}=0.6$
$\tan {30}^o=\frac{1}{\sqrt{3}}=0.577$
$astan\Phi >tan{30}^o$
$\therefore \Phi >{30}^o;\varphi ={31}^o$