A Numerical Study on the Bearing Capacity of Fly-Ash Reinforced with Fine Micropiles

Soil reinforcement technology is beneficial for weak and soft subgrade soils supporting the footing loads. Vertical reinforcement to it further enhances the bearing capacity substantially. Fine micropiles as vertical reinforcement are becoming more popular. This numerical study focuses on the performance of subgrade soil (fly-ash), reinforced with fine-micropiles as the vertical reinforcement. The numerical model was developed in SIGMA/W of GeoStudio 2016 based on laboratory model tests. Analysis was carried out to study the influence of length of the reinforcement, spacing between the reinforcing bars and their lateral extent beyond the footing edge on the bearing capacity and settlement of the foundation system. The analysis shows that the bearing capacity increases and the settlement decreases with a decrease in the spacing between the reinforcing bars and increase in their lateral extent beyond the footing edge. The maximum improvement in the bearing capacity of the reinforced fly ash was obtained as 340% with a corresponding decrease in the settlement of 86%. For all spacing and lateral extent values, the bearing capacity increases by increasing the length of the reinforcement bars.