A Binary-Medium Constitutive Model for Artificially Structured Soils Based on the Disturbed State Concept and Homogenization Theory

Triaxial compression tests were carried out on artificially structured soil samples at confining pressures of 25, 37.5, 50, 100, 200, and 400 kPa. A binary-medium constitutive model for artificially structured soils is proposed based on the experimental results, the disturbed state concept (DSC), and homogenization theory. A new constitutive model for artificially structured soils was formulated by regarding the structured soils as a binary medium consisting of bonded blocks and weakened bands. The bonded blocks are idealized as bonded elements whose deformation properties are described by elastic materials, and the weakened bands are idealized as frictional elements whose deformation properties are described by the Lade-Duncan model. By introducing the structural parameters of breakage ratio and local strain coefficient, the nonuniform distribution of stress and strain within a representative volume element can be given based on the homogenization theory of heterogeneous materials. The methods for determination of the model parameters are given on the basis of experimental results. Comparisons of predictions with experimental data demonstrate that the new model provides satisfactory qualitative and quantitative modeling of many important features of artificially structured soils.