Discussion on “A generalized three-dimensional failure criterion for rock masses”

There are many methods to construct true triaxial strength criteria for rocks. Jaiswal and Shrivastva (2012) proposed a strength criterion, named J–S criterion, in the deviatoric plane, which provides nearly the same misfits for true triaxial test data as the exponential criterion. It is difficult to calculate the strength at given σ2 and σ3 using the J–S criterion, and the multiple solutions to the nonlinear equation may induce confusion and mistake. Strength envelopes in deviatoric planes are not geometric similar; therefore, true triaxial test data cannot be grouped in the mean stress to check strength criteria in the deviatoric plane.