New failure criterion for rocks by using compression tests

In the present research a new non-lineal failure criterion in rocks called GIT criterion is established. The new criterion has been developed by the Ground Engineering Group from the University of Oviedo (Spain), and it can be expressed in terms of both normal and shear stresses (σn,τ), and principal stresses (σ3, σ1 ). Three characteristic parameters define the criterion, which are estimated applying nonlinear least squares regression methods, using the Levenberg-Marquardt (LM) algorithm. The novelty of this new criterion is that its determination can be carried out only by using uniaxial compression tests, which are more economic and easier to implement than triaxial tests. The theoretical formulation is accompanied by set laboratory tests, and the results obtained are compared with the classical criteria employed in rock mechanics, such as those of Mohr-Coulomb and Hoek-Brown.