Numerical modelling of deep mixed columns below embankmentsconstructed on soft soils

摘要

Deep mixed columns are commonly used to improve the bearing capacity and to reduce settle-ments below embankments and light structures on soft soils. The paper uses 3D numerical modelling to studythe behaviour of an embankment constructed on soft Finnish clay improved with deep mixed columns. Thecolumns are installed in four different c/c-spacings to study the influence of spacing on the settlement behav-iour and the increases in vertical stress in the soil and the columns. The stress strain behaviour of the soft soilis simulated with an advanced constitutive model which accounts for destructuration of interparticle bondingand large strain anisotropy. Back calculation of drained triaxial tests on deep mixed Vanttila clay demonstratethat the non-linear stress-strain behaviour of the columns can be modelled using an constitutive model with ahyperbolic stress-strain relationship.