Hello,
I have been wondering a little on the modelling of undrained behavoir in clays using the Hardening Soil Undrained A model, especially with regards to the prevalence of anisotrophy of clays in undrained loading. In order to model this behavoir, I have been using the NGI-ADP model, but this does not allow for any consolidation aspects to be considered.
When modelling the completely drained behavior, using the friction angle and cohesion from a traxial test should as far as I am aware yield correct results, however I am worried that these parameters would overestimate the strength in undrained loading, since the anisotrophy cannot be modelled. Do you have some thoughts about this? Would this primarily give overestimation of Msf in safety analyses, or also underestimate the resulting forces in regular loading phases? Would it perhaps be more correct to adjust the parameters to resemble the direct shear strength when using HS Undrained A?