Simple model for the cyclic behaviour of smooth sand-steel interfaces

The object of this note is the formulation of a simple elastoplastic model for the behavior of smooth sand-steel interfaces. Themodel is derived from a series of constant normal stiffness direct shear tests between a siliceous sand and a smooth steel plate. These testshighlight the importance of the shear stress degradation on the final value of the shear resistance and can be seen as the elementarymechanism that models in the laboratory the pile shaft-soil interaction. The goal of the presented model is to represent the observedbehavior in a very simple way by using a reduced number of constitutive parameters.