Analytical analysis of settlement and interaction - floating granular piled rafts, single and group of two units with the effect of partial stiffening

ABSTRACT Analysis of granular piled raft (GPR) foundations that involves interactions between the pile, the soil, and raft is very challenging and an interesting area of research in geotechnical engineering. The present study pertains to the analysis of a single and group of two partially stiffened floating GPRs where the material in the top region of the granular pile (GP) is stiffened by using geosynthetics, which has better engineering properties. Analysis has been conducted by assuming the soil to be linearly elastic continuum and using the solutions due to Mindlin and Boussinesq for a point load acting in the interior and on the surface of the soil medium for estimating the stresses and displacements at any point in the soil medium. Computations were performed to assess and report the normalized shear stresses (NSS) at the granular pile – soil interface, fractional load shared by the raft and the same shared by the granular pile along its shaft and base (FLSR, FLSP, and FLSB), the distribution of normalized contact pressure (NCP) beneath the raft. The results have been reported in a non-dimensional form suitable to be used for design.