Study of the Effect of Installation of Stone Columns on the Stability of Soil Slopes using Finite Element Method

Abstract

There are several ways to mitigate the failure of a soil slope. The installation of stone columns for this purpose, is easy as well as economical. As their strength is greater than that of soil, they disrupt the slip surfaces. Also being more porous, they dissipate the pore pressure generated in the soil in the vicinity of the stone columns to a certain extent. This paper illustrates 2D finite element analyses carried out to simulate the behavior of stone columns in cohesive soil using the computer program PLAXIS. Parametric study was conducted to analyze the effect of number, length and diameter of the stone columns on the Factor of Safety of the soil slope. The F.O.S. of the soil slope was predicted using prediction models created using artificial neural networks (ANN) considering slope geometry like slope angle and height, material properties like cohesion and angle and internal friction of soil as well as granular material used in the columns, and the stone column parameters like the stone column’s number, length, diameter and the centre to centre (c/c) distance between two adjacent columns as input parameters. It was found that introduction of stone columns significantly improved the stability of the soil slopes. Further, it was seen that all the parameters considered in the study influenced the Factor of Safety of the soil slope.