Geomechanics and Ground Control · Geomechanics · 2 marks · Multiple choice
The initial dry-rock Mohr circle has principal stresses σ₃ and σ₁. With full saturation and uniform pore pressure p, which plotted effective-stress circle applies?
Effective normal stress is total normal stress minus pore pressure. Both principal stresses shift left by p, to σ₃−p and σ₁−p, while their difference and circle radius stay unchanged. Diagram A shows that translation. Pore pressure does not add to one principal stress and subtract from the other.
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