I am trying to reproduce some Triaxial data from Coop et al. (1995) using the Hypoplastic Model with Intergranular Strain Concept on Triax.
So far, I cannot get a decent match for the normally consolidated clay. There seems to be a compromise between getting a resonable stress path and a resonable shear stiffness curve. Can you please provide some insights as to what I may be doing wrong?
Dear Hashmi, this is quite a typical shortcoming of hypoplasticity, which is explained in this paper: “Mašín, D. and Herle, I. (2007). Improvement of a hypoplastic model to predict clay behaviour under undrained conditions. Acta Geotechnica 2, No. 4, 261-268”. But this model has some other issues, for example it has not been yet combined with intergranular strain concept. In your case, I would focus on matching the stiffness curve by accepting inperfect stress path as inevitable hypoplasticity shortcoming. Regards David
Thank you for the prompt response David.
I will address further questions in a new post with a new pic.