Installation of groups of stone columns in clay: 3D Coupled Eulerian Lagrangian analyses

Abstract

This paper describes the results of three-dimensional (3D) finite element analyses investigating the installation effects of groups of stone columns in purely cohesive soils. Installation of stone columns is simplified to the insertion of rigid cylindrical elements with conical tips in a single homogeneous soil layer (Tresca plasticity and a quasi-incompressible elastic law). Installation of a single column is simulated as the reference case and the installations of two columns and a group of nine columns are considered to study the interaction between the installation of several columns and the influence of the installation sequence. The process is simulated using a Coupled Eulerian Lagrangian formulation. Stone column installation alters the surrounding soil and the numerical results show the increase in horizontal stresses and pore pressures. The installation effects of several columns at common spacings overlap between each other and accumulate, producing higher horizontal stresses and pore pressures in a larger area. The installation sequence is mainly visible around the last column installed, where the radial stresses are lower.