In active stress, the major principal stress σ1 acting on the wall will be in __________ plane.
(a) Vertical
(b) Horizontal
(c) Inclined
(d) Zero
This question was posed to me in a job interview.
My doubt stems from Plastic Equilibrium in Soils : Active and Passive States topic in chapter Failure Envelopes & Earth Pressure of Geotechnical Engineering II