A hierarchical elasto-plastic constitutive model for rammed earth

A hierarchical constitutive model based on the framework of elasto-plasticity is developed to model the mechanical behavior of rammed earth which is a quasi-brittle material. This model holds two mechanisms of plastic deformation, one related to shear failure and another one to a tensile mode of failure. Different hierarchies for the model, which are merely levels of complexity, are proposed according to the amount of information available to identify the model parameters. The model was validated simulating a diagonal compression test and a pushover test on a wallette. The simple elasto-plastic model (level-1) was able to capture some basic features of the rammed earth behaviour essentially for a rather small range of deformations, it can be used for a first estimate of the loading capacity of a system. The more sophisticated model (level-2) was able to quantitatively retrieve the non-linear behavior of rammed earth over a larger range of deformations.