TY - JOUR
T1 - A state-dependent multilaminate constitutive model for anisotropic sands
AU - Bayraktaroglu, Hilmi
AU - Hicks, Michael A.
AU - Korff, Mandy
AU - Galavi, Vahid
PY - 2023
Y1 - 2023
N2 - Experimental studies show that initial fabric and its evolution under different stress paths highly influence soil behaviour. Even though different sample preparation methods create different inherent anisotropies and cause different material responses, the same initial fabric structure under different stress paths also results in different material behaviours. In this paper, a simple state-dependent, bounding surface-based elastoplastic constitutive model, that can simulate the anisotropic nature of sands including the effect of principal stress rotation, is described. The model is developed based on a semi-micromechanical concept within the multilaminate framework and, to include the inherent anisotropy of sand, a deviatoric fabric tensor describing the initial microstructure is introduced. In addition, a fabric evolution rule compatible with anisotropic critical state theory (ACST) is employed to describe the evolving fabric structure and induced anisotropy towards the critical state (CS). In contrast to the classical strain-driven formulation for fabric evolution, a micro-level evolution rule is proposed. This paper presents concise theoretical aspects of the multilaminate framework and the anisotropic elastoplastic constitutive formulation. The model's capability under drained and undrained monotonic loading conditions at different stress states, relative densities and principal stress orientations is demonstrated by simulating experimental data for Toyoura sand.
AB - Experimental studies show that initial fabric and its evolution under different stress paths highly influence soil behaviour. Even though different sample preparation methods create different inherent anisotropies and cause different material responses, the same initial fabric structure under different stress paths also results in different material behaviours. In this paper, a simple state-dependent, bounding surface-based elastoplastic constitutive model, that can simulate the anisotropic nature of sands including the effect of principal stress rotation, is described. The model is developed based on a semi-micromechanical concept within the multilaminate framework and, to include the inherent anisotropy of sand, a deviatoric fabric tensor describing the initial microstructure is introduced. In addition, a fabric evolution rule compatible with anisotropic critical state theory (ACST) is employed to describe the evolving fabric structure and induced anisotropy towards the critical state (CS). In contrast to the classical strain-driven formulation for fabric evolution, a micro-level evolution rule is proposed. This paper presents concise theoretical aspects of the multilaminate framework and the anisotropic elastoplastic constitutive formulation. The model's capability under drained and undrained monotonic loading conditions at different stress states, relative densities and principal stress orientations is demonstrated by simulating experimental data for Toyoura sand.
KW - anisotropy
KW - constitutive relations
KW - fabric/structure of soils
KW - plasticity
KW - sands
UR - http://www.scopus.com/inward/record.url?scp=85151539158&partnerID=8YFLogxK
U2 - 10.1680/jgeot.22.00165
DO - 10.1680/jgeot.22.00165
M3 - Article
AN - SCOPUS:85151539158
SN - 0016-8505
JO - Geotechnique
JF - Geotechnique
ER -