Statistical and Numerical Study on the Performance of Skirted Foundations in Clayey Soil

Abstract

Skirted foundation is considered as an alternative approach required for improving the bearing capacity of shallow foundations, by using structural skirts fixed to the edges of the foundation. The presence of vertical skirts at the base of footing generates a soil resistance on skirt side beneath the footing, which helps to resist sliding. For this purpose, a numerical analysis has been performed in order to explore the behavior of square and strip model footings with one and two sided skirts for different embedded ratio in soft clay. In this study, a vertical skirt depth (Ds) has been considered as the main parameter that significantly affects the bearing capacity. Finite element analysis using plaxis 3D Foundation has been performed to model the skirted foundation. This work indicated that, using structural skirts in one and two sides of footing has a paramount effect in improving the bearing capacity for both strip and square footings and a marginal precedence has been noticed for the strip once. Therefore, the results have demonstrated that the average improvement in bearing capacity in soft clay for the one and two sided skirts at skirted ratio of Ds/B=2 is 170 and 220% respectively. A derived equation has been proposed to calculate bearing capacity of skirted foundation and a feasible agreement has been obtained between the observed and there predicted test results where the coefficient of regression (R2) is found to be 90%.