The following results were obtained from a CU on two samples:
Test no. Confining stress (kPa) Deviatoric stress (kPa) Pore pressure (kPa)
1 100 400 -20
2 300 760 60
a) Determine c and ƒÖ for total stress and effective stress condition.
b) What is the deviatoric stress at failure if the confining stress is 500 kPa?
c) What is pore pressure at failure?