Question

For a railway track 6.0 m high embankment was required. The clay to be used was having cohesion as $20kN/m^2$ and unit weight of $20.3kN/m^3$. If the hard rocky stratum was found 3.0 m below the ground level, the permissible slope angle for embankment should be degrees.
$(Assume\varphi =0^{\circ })$
Depth factor $D_f=1.5$

$$\begin{array}{cc}{S}_n& i\\ 0.181& {53}^{\circ }\\ 0.164& {30}^{\circ }\\ 0.174& {45}^{\circ }\end{array}$$

• A. ${30}^{\circ }$
• B. ${26}^{\circ }$
• C. ${18}^{\circ }$
• D. ${53}^{\circ }$

Answer 1

The correct option is A ${30}^{\circ }$

$Forpermissibleslopeangle,F_c=1$

$F_c=\frac{C}{S_{n}rH}$

$\therefore S_n=\frac{20}{20.3\times 6}=0.164$

$Depthfactor,D_f=\frac{H+D}{H}=\frac{6+3}{6}=1.5$

$Fromtable,D_f=1.5,S_n=0.164\Rightarrow i={30}^{\circ }$