Question

If a point load of 50 kN is applied on a homogenous, isotropic soil mass. What will be the stress at 5 m below the point of application of load as per Boussinesq theory?

• A. $0.42kN/m^2$
• B. $0.65kN/m^2$
• C. $0.95kN/m^2$
• D. $1.2kN/m^2$

Answer 1

The correct option is C $0.95kN/m^2$

Stress at depth z just below the point load Q.



${\sigma }_z=k_B\frac{Q}{z^2}$

$K_B=\frac{3}{2\pi }{\left[\frac{1}{1+{\left(\frac{r}{z}\right)}^2}\right]}^{5/2}$

${\sigma }_z=k_B\times \frac{Q}{z^2}$

${\sigma }_z=0.4775\times \frac{50}{(5{)}^2}$

${\sigma }_z=0.955kN/m^2$