A Statistical Damage Model for the Soil–structure Interface Considering Interface Roughness and Soil Shear Area

A statistical damage model is proposed to investigate the impacts of the interface roughness and the shear area of the soil on shear deformation characteristics at the soil– structure interface. Assuming that the damage to the soil shear plane and the soil–structure interface follows Weibull distribution damage theory, the model introduces an equivalent initial damage factor that considers the effect of interface roughness. Results indicate that the interface roughness and soil shear area considerably influence the shear stress–displacement relation at the soil–structure interface. Under the same normal stress, the strengths of the soil–structure interface and the soil shear plane approach with increasing interface roughness and soil shear area. Furthermore, the total damage to the soil shear plane during sample loading is due to load-induced damage, whereas the total damage to the soil–structure interface comprises the equivalent initial damage, load-induced damage, and coupled damage arising from the interactions between the equivalent initial damage and load-induced damage. The feasibility of the model was verified by comparing the theoretical and experimental results, which indicate that the model can well predict the shear deformation behavior of the soil–structure interface under different soil shear areas and interface roughnesses.