A three-dimensional criterion for asymptotic states

The asymptotic state of a soil is affected by stress states and deformation constraints. Experimental results indicate that the stress ratio approaches a constant when soil is loaded along with a strain path. Such a stable state is referred to as the asymptotic state. Indeed, failure can be viewed as a special condition of asymptotic states. Therefore, the shear strength of a soil at its failure state can also be interpreted by the criterion for asymptotic states. A three-dimensional criterion for asymptotic states that can take into account the influence of deformation constraints is proposed in this technical note. By involving both triaxial compression and extension tests to calibrate a new fitting parameter, α, the proposed criterion can provide an accurate simulation of the influence of Lode's angle. The performance of the proposed three-dimensional criterion for asymptotic states is investigated via numerical examples and then validated against experimental results.