Finite Element Modeling of a Stone Layer Under a Strip Footing to Estimate Soil Behavior and Determine Optimal Stone Layer Width and Depth

Abstract

Various methods can be applied to improve soil behavior in order to increase the bearing capacity or reduce the settlement of footings. These methods can be categorized as stabilization or improvement of soil by use of different geosynthetics; injection methods; grouting or replacing weak soil with stronger materials. One of the most common methods and materials that can be used for improving soils, is placing a stone layer under the footing. In this study, a stone layer under a strip footing is simulated with the finite element method (FEM) to estimate the soil behavior in different conditions. A strip footing with a width of 1m and length of 8m with a 100 kN/m2 uniform load was modelled. Different widths of stone layer from 1B to 3B (B was the strip footing width) with different depths of 0.5B, 1B, 1.5B, and 2B were modelled in Plaxis 3D and results were obtained from the simulation. By reviewing the results, it was found that the optimum dimensions of the stone layer to place under the presented strip footing was 2B width and 1B depth. This result can be applied to real projects with similar conditions.