Seminar - Itai Einav - Breakage (Soil) Mechanics
Wednesday 28 March 2007, 1.10 - 1.50 pm
Civil Engineering Lecture Theatre 3
Critical state soil mechanics (CSSM) was originally developed for clays. For this application CSSM continues to provide the most elegant mathematical theory for capturing the physics of the material. In its simplicity, only five parameters are needed to describe a broad range of critical effects. However, when CSSM is adapted to model sand-agglomerates, models can no longer be accurately defined using five parameters. The CSSM theory requires fitting the slope λ of the "isotropic-hardening" compression line in the void-ratio/logarithm-of-pressure space. The problem is that in sands the slope is no longer unique and the fitting exercise is doomed to fail. Another constant, the "specific volume parameter" N, ceases to be a constant in sand and becomes heavily dependent on the grain size distribution and initial void ratio. These inconsistencies are widely accepted but have not yet been overcome, at least not without adding parameters.
In my talk I will present a new theory called "breakage mechanics", when generally applied to brittle granular materials, or "breakage soil mechanics" when specifically applied to sands, which resolves the aforementioned problems.
Einav, I. 2007. Breakage mechanics. Part I- theory. J. Mech. Phys. Solids. Available online (doi:10.1016/j.jmps.2006.11.003)
Einav I. 2007. Breakage mechanics. Part II- modelling granular materials. J. Mech. Phys. Solids. Available online. (doi:10.1016/j.jmps.2006.11.004)