Question

Find the depth z for a uniformly loaded circular area of 80 kN/m^2 load and radius of 50m. k=0.9160.

(a) 2m

(b) 4m

(c) 25m

(d) 50m

This question was addressed to me in an interview for job.

I need to ask this question from Stress Distribution topic in portion Stress Distribution of Geotechnical Engineering I

Answer 1

The correct answer is (c) 25m

The best I can explain: Given,

uniformly loaded circular area of radius a=50m

load q=80 kN/m^2

k=0.9160.

The Boussinesq’s influence factor k under a uniformly loaded circular area is given by,

\(k=\left[1-\left[\frac{1}{1+(\frac{a}{z})^2}\right]^\frac{3}{2}\right]\)

∴ \(0.9160=\left[1-\left[\frac{1}{1+(\frac{50}{z})^2}\right]^\frac{3}{2}\right]\)

∴ z=25m.