Composite granular pile foundation for high water table areas

Composite granular pile foundation consisting of shallow well steining and a stiffer granular core is being proposed for high water table areas. Shallow well steinings, locally available are sunk to the desired depth by the conventional well sinking technique. Soil within the steining is removed and granular material filled in and compacted. The proposed foundation shows high stiffness and stability as it utilizes the passive resistance of soil: Model studies were carried out and load or stress vs. settlement response of the tested foundation is evaluated. Some of the factors considered in this study are the diameter and depth to diameter ratio of composite foundation with granular core. Effects of the variations of unit weight and consequently of the modulus of deformation or subgrade reaction of the soil with depth, due to the installation of the proposed foundation, are studied. Observed response of the composite foundaton is compared with the predicted one.