抄録
In the present paper, a Cosserat type elasto-viscoplastic Cosserat model for clay is proposed with couple stress and characteristic length scale. The model is applied to the numerical analysis of strain localization water saturated clay by FEM. In the FE analysis, Biot type of mixture theory was adopted to formulate governing equations. Two types of numerical analyses were conducted. One is the analysis of the behavior under the simple shearing and the other is analysis for the clay specimen with imperfection under the plane strain compression conditions. It was found that the strain rate and the characteristic length scale greatly affect the shear strength and stiffness. In addition, it was found that there is a critical value of characteristic length scale over which the numerical results does not depend on the length scale. The introduction of characteristic length scale into the analysis diminishes the mesh size dependency.
