Discussion: An elasto-plastic model for unsaturated soil incorporating the effects of suction and degree of saturation on mechanical behaviour

Abstract

D. GALLIPOLI, A. GENS, R. SHARMA and J. VAUNAT (2003).Ge´otechnique53, No. 1, 123–135J. Robles, Technical University of MadridL. R. Hoyos, University of Texas at ArlingtonThe authors should be commended for presenting such aninnovative, elaborate elasto-plastic framework for predictingconstitutive unsaturated soil response under isotropic stressstates. One of the key aspects of the work is the authors’deep knowledge of the physical interactions that lie behindthe mechanical behaviour of unsaturated soils. The proposedconstitutive model and their associated conceptual frame-work provide an important improved understanding of soilbehaviour. The present review is intended to offer somecomments that further highlight the relevance of the workand its potential for further refinement and tuning.The objective of this review is twofold:(a) to propose an alternative numerical procedure forobtaining the analytical expression for the assumedfundamental assumption(b) to discuss the effectiveness of the proposed model withregard to the ‘direct’ relationship between the mech-anical and hydraulic responses of unsaturated soils forirreversible stress paths.Inspection of Fig. 6 suggests that, for a suction state ofs