Experimental Proof of the Existence of a Bifurcation Process During the undrained test in Clay
M. Hattab : LPMM/ISGMP,UMR 7554 CNRS, Université de Metz, île de Saulcy, 57045 METZ cedex 01, France, firstname.lastname@example.org
Abstract: Recent papers, based on a new simple incremental modelling which assumes an "isotropic" response , predicts that the trajectory followed during an undrained compression test exhibits a bifurcation process when the stress field arrives at q=M'p', i.e. indicating a discontinuous change of solution when arriving at q=M'p'. This paper looks at experimental data on dense sample obtained at p'=cste, and it shows that the trajectory (p'=cst, v=cst) does continue to exist at and beyond the q=M'p' plane. So, this demonstrates the validity of the analysis which uses the bifurcation theory and this strengthens the proposed modelling. Indeed, this demonstrates the reality of the bifurcation process during undrained compression.