Question

From the symmetry and orthogonality of principal planes ____________

(a) both horizontal and vertical planes will be devoid of shear stress

(b) both horizontal and vertical planes will have shear stress

(c) only vertical plane has shear stress

(d) only horizontal plane has shear stress

I had been asked this question in a job interview.

Asked question is from Stresses due to Self Weight topic in section Stress Distribution of Geotechnical Engineering I

Answer 1

Correct choice is (a) both horizontal and vertical planes will be devoid of shear stress

The explanation is: From the symmetry and orthogonality of principal planes, one can conclude that both horizontal and vertical planes will be devoid of shear stress.

∴ τYX= τYZ = τXZ=0.