Hi Prof. David,
I have obtained these results in that attached picture using Triax and got confused when seeing that an isotopically normally consolidated sample does not follow a trend that looks similar to the traditional Roscoe Surface. Have I done something wrong or this is what is expected from your hypoplastic model?
Thank you,
Hashmi
Dear Hashmi, this is correct response of the model. Actually, the observed shape of stress path is due to response envelopes being translated elipses in the stress space. The normally consolidated sample response can be corrected by either using intergranular strain concept, or by so-called D-dependent L approach. It is discussed thoroughly in this reference: 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. Regards David
ok, thank you David.
Can you please provide a clarification on the following:
In triax program, the following are the inputs when using hypo_clay with istrain:
fi cr, lambda, kappa, N, r, R, mr, mt, betar, chi, e0
however, when referring to your notes, it says that for hypo_clay mR is replaced by Ag and ng while mT is supplemented by mrat instead. Therefore, how can i make triax recognise these input parameters: Ag, ng and mrat?
Correct, this is because hypo_clay is 2005 version of clay model. To use the most recent clay version, use hypo_clay_anisot and set anisotropy factor alpha_G = 1. Regards David
ok thank you. is there an updated pdf manual that includes the newer versions of hypo_clay models in triax that came after 2005?
I am currently using hypoplasti_clay_anisot_istrain, can you please confirm that the parameter nu is poisson’s ratio?