Modelling instabilities in triaxial testing on unsaturated soil specimens

• DOI: 10.1002/nag.832
• Publication Date: 2009-09-11T15:28:38Z
• Authors: Giuseppe Buscarnera; Roberto Nova
• Keywords: Saturation (graph theory); Soil Mechanics; Soil test

Abstract The paper presents a theoretical approach to deal with mechanical instabilities in unsaturated soils. Towards this goal, the concept of test controllability is extended hydro‐mechanically coupled framework. A constitutive based on introduction hydraulic generalized stress–strain variables first adopted, order better describe suction effects behaviour soil. mathematical consequences hydro‐mechanical coupling are presented next and two indices defined identify onset an instability. Possible instability modes linked saturation processes discussed. It shown that way which controlled tests soil specimens key factor for possible occurrence consequent loss controllability. particular prone when externally water flux injected into specimen (inundation). This result could part explain sudden collapse subjected wetting under constant applied stresses, observed both laboratory field. Copyright © 2009 John Wiley & Sons, Ltd.