This paper is dedicated to the non-linear numerical modelling of the soil-structure interface. Thus, in a first part, after the presentation of the constitutive model, the soil-structure interface interaction is treated in terms of direct shear test simulations. A strategy for the interface model parameters' identification is also presented. This strategy is linked to the similitude of soil-structure interface behavior and the soil behavior, regarding the interface surface roughness. In a second part, the performance of the numerical simulations are verified numerically against published results for soil-structure experimental shear tests. Finally, as an application, interface stress paths are studied in axially loaded pile-soil systems and load transfer mechanisms are identified.