2005/07/05 by P. Evesque
Physics and Astronomy · #cond-mat.soft
published as Poudres & Grains 11, 60-63, (2000), ISSN 1257-3957 · 4 pages + 1 page, 1 Figure
arxiv created 2005/07/05 · arxiv updated 2009/12/01
In general, the evolution of soil submitted to simple stress-strain paths is characterised using the 3d phase space (v,p',q) i.e. (specific volume, mean intergranular pressure, deviatoric stress q. When uniaxial compressions is performed at constant lateral pressure p' or at constant mean pressure p', one finds that all trajectories end up at a line of attracting point called the critical-state line via the surface of Roscoe or of Hvorslev depending if the initial volume is the loosest possible one (at a given p') or densest. Trajectories of weakly dense samples are not often reported in this phase space. We find here that they shall present some sigmoid shape as it can be found from soil mechanics argument. This seems to indicate that Roscoe's surface shall exhibit a singularity at the critical point.