Numerical Analyses of the Optimum Length for Stone Column Reinforced Foundation

Abstract

The paper presents 3D numerical simulations that investigate the settlement performance for small groups of stone columns under a rigid circular footing. Particular consideration is given to the effects of stone column installation and load level on the optimum length of the stone columns. The results show that taking into account the installation effect by increasing the lateral earth pressure coefficient of the soil reduces the deformation of the columns and the surrounding soil. This leads not only to a reduction in the settlement of the footing but also to a reduction in the optimum length of the stone columns. This optimum length of columns is not constant, it increases with the increase in the load applied to the footing. However, overestimating the installation effect has a negligible consequence on the footing settlement and the optimum length of columns. In addition, the study shows that, for loads exceeding the working load levels of unreinforced soil, the optimum length of the columns is controlled by the extent of the total shear strains beneath the footing evolving with the applied load.