A constitutive model for gravelly soils considering shear-induced volumetric deformation
Journal
Canadian Geotechnical Journal
Journal Volume
47
Journal Issue
6
Start Page
662
End Page
673
ISSN
00083674
Date Issued
2010
Author(s)
Abstract
This study elucidates the deformational behavior of gravelly soils by analyzing how hydrostatic pressure and pure shearing affect deformational behavior. A series of drained, triaxial compression tests have been performed using large specimens made of gravelly soils, where the grain-size distribution curve was based on the field condition. The volumetric and shear deformations of gravelly soils have been determined by performing experiments with controlled stress paths - hydrostatic pressure was applied first followed by pure shearing. A simple and innovative constitutive model is also proposed. The proposed model is characterized by the following features of gravelly soils: (i) significant shear-induced volumetric deformation prior to failure, (ii) modulus stiffening under hydrostatic loading and degradation under shearing, and (iii) stress-induced anisotropy. In the proposed model, deformational moduli K and G vary according to the stress state. The stiffening and degradation of these moduli result in diverse deformational behavior of gravelly soils. In addition, an anisotropic factor, b, is introduced to represent stress-induced anisotropy. Moreover, the proposed model only requires eight material parameters; each of which can be obtained easily from experiments.
Subjects
Constitutive model
Gravelly soil
Pure shearing
Shear-induced volumetric deformation
Type
journal article