A constitutive model for cemented sands

A theoretical investigation on the behaviour of cemented sand subjected to different tri-axial compression loading is reported. The essential feature of the model presented is the combined frictional hardening and cohesional softening. The model is formulated in an integral continuum approach. The volumetric strain measure which controls the evolution law of the softening is defined in a non-focal way. By introducing a parameter with the quality of an internal length the results of simulations get independent of the discretization when using FEM. The physical bases for the proposed forms are discussed in detail. The model is verified with the calculation of shear tests on different cemented sands found in literature. Additionally a biaxial test with an imperfection is simulated to study the evolution of strain localisation. The model is capable to simulate the main characteristics of the experimental stress strain behaviour, both qualitatively and quantitatively.