Question

For a vertical concentrated load acting on the surface of a semi-infinite elastic soil mass, the vertical normal stress at depth 'z' is proportional to

• A. $z$
• B. $1/z$
• C. $z^2$
• D. $1/z^2$

Answer 1

The correct option is D $1/z^2$

According to Boussinesq's theory,
${\sigma }_z=\frac{3Q}{2\pi z^2}{\left[\frac{1}{1+(r/z{)}^2}\right]}^{5/2}=K_B\frac{Q}{z^2}$