The following linear failure envelopes for a rock mass are given:
Intact rock
Friction angle = 350
Cohesion = 900 psi
Tension cut-off = 350 psi
Discontinuity
Friction angle = 300
Cohesion = 100 psi
Tension cut-off = 0 psi
Using both graphical and analytical methods in assessing the stability of the rock mass and calculate factors of safety for both the intact rock and the discontinuity for the following stress conditions:
s1 = 5000 psi
s 3 = 1000 psi
Orientation of a discontinuity, b = 600