Effect of Subbase Stabilization on the Bearing Capacity of Footing Resting on Clayey Soil

This paper presents a comprehensive investigation into the influence of subbase layer thickness and shear strength on the performance of footings situated on very soft, soft, and medium clays using two-dimensional finite element analysis. Subbase thicknesses of 0.5, 1.0, 1.5, and 2.0 m have been considered in the study based on practical considerations related to excavation stability and cost-effectiveness. It has been found that increasing subbase thickness increases the ultimate bearing capacity, with average percentage increase ranging from 14 to 64%. Furthermore, it has been found that the shear strength parameters of the subbase layer have minor effect on the ultimate bearing capacity. Importantly, a new predictive model has been proposed using the results obtained from the numerical analyses to enable fast and accurate calculation for the ultimate bearing capacity considering the subbase soil replacement. The predictive model scored a coefficient of determination of 0.99, which indicates an excellent prediction accuracy.