Soil structure interaction analysis: modeling the interface

The sand-structure interface, developed under monotonic loading, was modeled based on physical observations. The model takes into account the macroscopic conditions to yield a general constitutive law applicable to a wide range of contact problems and the microstructural considerations constitute the specialization of the general equations to a specific problem. The surface of slippage was idealized to be sinusoidal based on an intensive numerical simulation program that made use of the discrete element technique. The model incorporates the effect of grain crushing found to play a major role in the behavior of the interface. Analysis of laboratory data revealed a close relationship between grain crushing and the work dissipated plastically during shear. The proposed elastoplastic model, requiring a limited number of parameters, predicts the shear stresses for the modified direct shear test and reproduces the shaft resistance of the shaft-sand interface pullout tests in a satisfactory manner.