Numerical Modelling of Stone Column Installation Effects on Performance of Circular Footing: Fid-Bau Portal

Numerical Modelling of Stone Column Installation Effects on Performance of Circular Footing

Benmebarek, Sadok / Remadna, Abdeldjalil / Benmebarek, Naima

Abstract In this paper, numerical analyses using Plaxis 2D code in axisymmetric model are carried out to evaluate the influence of stone column installation effects on the loading–settlement performance of circular footing supported by a small group of columns. First, the column installation inducing lateral expansion is modelled using large displacements as the undrained expansion of a cylindrical cavity. The focus is made on the evaluation of the installation effects in terms of stiffness and effective vertical, radial and circumferential stresses immediately after column installation and after consolidation. The results show that the dissipation of excess pore pressure, due to column installation, leads to more improvement in the effective radial than circumferential stresses in the vicinity of the column which induce to a significant increase in effective mean stress as well as the surrounding soil stiffness. Then, numerical investigations are performed on column group supporting a rigid circular footing to evaluate the influence of each improvement installation effect by producing the loading–settlement response. The results show more improvement of settlement is obtained when considering both effective horizontal stresses and soil stiffness improvements due to column installation and the improvement is more pronounced for high footing loading. Moreover, the columns bulging are mainly controlled by the effective horizontal stresses.