Numerical analyses of stone column installation in Bothkennar clay

The paper presents the results of numerical simulations studying the installation effects of stone columns in a natural soft clay. Stone column installation is modelled as an undrained expansion of a cylindrical cavity, using the finite element code PLAXIS that allows for large displacements. The properties of the soft clay correspond to Bothkennar clay, a soft Carse clay from Scotland (UK). The complexity of this material is simulated via two advanced recently developed constitutive formulations able to account for the soil structure, namely S-CLAY1 and S-CLAY1S. Modified Cam Clay model is also used for comparison purposes. The paper shows the new stress field and state parameters after column installation and the subsequent consolidation process. This sets the basis for including installation effects in studying the settlement reduction caused by stone columns