Testing and Modeling of Saturated Interfaces with Effect of Surface Roughness. II: Modeling and Validations

The data from comprehensive interface simple shear tests on saturated interfaces, presented in Part I of this paper, were used to calculate the parameters in the disturbed state concept (DSC) model. The resulting parameters were then used to verify the DSC model by back-predicting tests from which parameters were determined and by independent tests that were not used in parameter determination. The model predictions, in general, were found to provide highly satisfactory correlation with the observations. In the context of DSC, the concept of critical disturbance was developed to identify initiation of liquefaction in saturated Ottawa sand-steel interfaces; this method is based on microstructural changes in the deforming material leading to instabilities like liquefaction. A new and unique constitutive modeling approach, testing, and validations for interface behavior affected by factors such as surface roughness, confining pressure, amplitude and frequency of cyclic loading are presented in this two-part paper.