Constitutive modelling of cohesionless soils and interfaces with various internal states: An elasto-plastic approach
A discussion is led on a constitutive modelling of granular soils and soil-structure interfaces for which large changes in their internal state are likely to take place throughout loading. Relevant variables accounting for this internal state are discussed. They must include the effects of both the specific volume and the mean pressure and also the influence of the contact directions of the granular assembly related to induced anisotropy in the granular material. Two elasto-plastic constitutive models for the volume element of soil and for soil-structure interfaces are presented. They were designed in such a way that with a unique set of model parameters, very different internal states can be addressed throughout cyclic loadings. The validation of the constitutive models was performed on the basis of experimental tests performed using Fontainebleau sand. Finally, the validation is achieved studying a boundary value problem involving cyclic axially loadings on a pile located in a sand massif. The simulations showed results in a fairly good agreement with the results obtained from corresponding centrifuge tests confirming the predictive capability of the two constitutive models.
elasto-plasticity granular soils cyclic loading critical state mechanics soil-pile interaction