Volume Averaging Technique in numerical modelling of floating deep mixed columns in soft soils

Paper in proceeding, 2013

The deformation behaviour of deep mixed columns in anisotropic soft soil is a threedimensional problem which has to be considered adequately in numerical modelling. However, in literature simplifications are often to be found due to computational costs of fully coupled 3D analyses by either modifying geometry of the problem or material parameters in 2D-plainstrain or -axisymmetric conditions. This paper uses an enhanced 2D volume averaging technique for numerical modelling of deep mixed columns. The method enables mapping the 3D problem in two dimensions, and yet modelling the two constituents (column and soft soil) appropriately within a homogenized material. The performance of the technique is demonstrated by considering unit cell simulations of floating columns in soft soil, in which the results from 2D finite element simulations utilizing volume averaging technique are compared against conventional and fully 3D coupled finite element analyses. It is shown that the quality of the match is very good but depending on the number of columns and stiffness ratio between columns and soft soil.