Question

The deviator stress developed in the proving ring, through the applied pressure is equal to are____________

(a) σ1 + σ3

(b) σ1 – σ3

(c) σ2 – σ3

(d) σ2 + σ1

I have been asked this question in a national level competition.

My doubt stems from Tri-axial Compression Test in portion Shear Strength of Geotechnical Engineering I

Answer 1

Correct option is (b) σ1 – σ3

Explanation: The vertical stress applied by the loading frame, through the proving ring is equal to (σ1 – σ3); this stress difference is called the deviator stress.