This work addresses the deep penetration of structures in clays; particularly the Cone
penetration test. CPT is one of the most widely used in situ method to characterize
soil properties. A large number of correlations have been obtained using a multitude
of techniques; however, there is still a large spread between the proposals.
The research has been carried out by large deformation calculations employing
the Particle Finite Element method. In this method, the domain is discretized with
a set of particles; the interaction between them is computed in a nite element mesh
with low order elements and a lagrangian description of the domain. This mesh
is created frequently; adaptive remeshing strategies and techniques to recover the
boundary are used.
In this work, an explicit integration scheme for hyperelastic-based nite strains
elasto-plasticity is proposed. One step update equations are obtained from the large
deformation multiplicative elasto-plasticity theory, where an exponential variation of
the plastic deformation gradient is assumed. In addition, the material tangent matrix
is presented and has the same formal structure as the usual small strains elastoplastic
tangent matrix. Routines to alleviate the main drawbacks of explicit methods
are outlined, suh as a yield drift correction scheme and an adaptive substepping
method. Several examples of typical geotechnical tests are presented, showing the robustness and accuracy of the proposal.
Results of the simulation of the cone penetration in undrained clay are reported.
A parametric study in total stresses is carried out for materials obeying a Tresca
yield criterion. The variables investigated are the rigidity index and the roughness
at the interface of the soil and the structure. Details on the stress state and the
incremental displacements pro les are presented.
Finally, the drained penetration on soils obeing a Modi ed Cam Clay model
elasto-plastic behavior is assessed and the stress state and the stress path are commented.
