An advanced hydro-mechanical constitutive model for unsaturated soils with different initial densities. (January 2015)

• Record Type: Journal Article
• Authors: Zhou, Annan; Sheng, Daichao
• Is Part Of: Computers and geotechnics. Volume 63(2015)
• Page Start: 46
• Page End: 66
• Publication Date: 2015-01
• Subjects: Unsaturated soils -- Compacted soils -- Bishop's effective stress -- Degree of saturation -- Hydro-mechanical interaction -- Initial densities; Engineering geology -- Data processing -- Periodicals; Soil mechanics -- Data processing -- Periodicals; Rock mechanics -- Data processing -- Periodicals; 624.1510285
• DOI: 10.1016/j.compgeo.2014.07.017
• Languages: English
• ISSNs: 0266-352X

Abstract

Abstract: This paper presents an advanced constitutive model for unsaturated soils, using Bishop's effective stress ( σ ′) and the effective degree of saturation ( S e ) as two fundamental constitutive variables in the proposed constitutive model. A sub-loading surface and a unified hardening parameter ( H ) are introduced into the σ ′– S e modelling framework to interpret the effects of initial density on coupled hydro-mechanical behaviour of compacted soils. Compared with existing models in the literature, the main advantage of the proposed model that it is capable of modelling hydro-mechanical behaviour of unsaturated soils compacted to different initial densities, such as the dependence of loading–collapse volume on initial void ratio and density effect on the shearing-induced saturation change. The proposed model requires 13 material parameters, all of which can be calibrated through conventional laboratory tests. Numerical studies are conducted to assess the performance of the model for a hypothetical soil under two typical hydro-mechanical loading scenarios. The proposed advanced unsaturated soil model is then validated against a number of experimental results for both isotropic and triaxial conditions reported in the literature.