A Failure Criterion for Rocks Based on True Triaxial Testing

Excerpt

The failure criterion based on true triaxial testing considers the effect of all three principal stresses on rock compressive strength, and is entirely based on true triaxial tests conducted on rectangular prismatic specimens subjected to three independent principal stresses. The failure criterion is commonly expressed in terms of the octahedral shear stress as a monotonically increasing function of the mean effective normal stress acting on the plane of failure. In tests conducted thus far the function best fitting experimental data is the one obeying the power law. This criterion was first derived by Mogi (1971) and confirmed for several other rocks by Haimson and Chang (2000), Chang and Haimson (2000), Oku et al. (2007) and Lee and Haimson (2011). …