NUMERICAL-MODEL OF 3-DIMENSIONAL ANISOTROPIC DEFORMATION AND 1-DIMENSIONAL WATER-FLOW IN SWELLING SOILS

Current models of water flow in deforming soils generally involve a tr ansformation from spatial to material coordinates, Existing forms of t his coordinate transformation either assume that soil deformation is o ne-dimensional, or that it is isotropic, In the present article, we pr opose a new expression of the transformation gradient tensor, that all ows different extents of deformation in the vertical and horizontal di rections, The resulting generalized water flow equation is calibrated with experimental data obtained for one-dimensional vertical infiltrat ion in a bentonite sample, The hydraulic characteristics obtained from this calibration are then used to analyze, via simulations, the sensi tivity of water flow to anisotropy in soil deformation, The results in dicate that the extent of the lateral deformation strongly influences not only the height of the soil surface, as expected, but also the dis tribution of water and the total volume of water in a swelling/shrinki ng soil undergoing infiltration or drainage, Consequently, this latera l deformation should be taken into account explicitly in modeling effo rts or in the determination of the hydraulic characteristics of soils that deform anisotropically.