Question

When the ratio of r/z equals to 1, the Boussinesq influence factor is ________ of the maximum.

(a) 23%

(b) 57%

(c) 17.7%

(d) 1.8%

This question was addressed to me in homework.

This interesting question is from Stress Distribution in section Stress Distribution of Geotechnical Engineering I

Answer 1

Right option is (c) 17.7%

Easiest explanation: Given,

r/z=1

The maximum KB is given by,

r/z=0, therefore KB=0.4775

for r/z=0.5, KB=0.0844

∴ the Boussinesq influence factor is 0.0844/0.4775*100=17.7% of the maximum.