I was wondering if someone could help with the following:-
I am trying to understand the concept of principal stresses in terms of soil mechanics.
I have a soil element that is being loaded by 25kN. I am trying to draw all of the stresses the soil element experiences.
I have attached a drawing of my soil element, the bit I cannot get my head round is the last cube which I got from an online source which shows the Principal stresses 1 3, would it be correct to say that:-
Sigma1 = 25kN worth of stress acting downwards & upwards
Sigma3 = ?????? No idea where this comes from?
You need to study up on Mohr's Circle for plane stresses.
Tell me and I forget. Teach me and I remember. Involve me and I learn.