Effect of Granular Pile Stiffness on Load Distribution for Piled Raft

Granular piles are a cost-effective technique of ground improvement which improves the load-carrying capacity, reduces the displacement of foundations built on the reinforced ground, and also a good alternative option of concrete pile. The reinforcement of ground becomes a necessity in many situations, where the soil is extremely weak or soft. The columns of granular material create an improved ground of lower compressibility and higher shear strength that of situ soil. Piles under the raft are designed to decreases the settlements and differential settlement of the soil. Raft, piles, and soil are three components of piled raft system through which the loads transfer to the subsoil. The present analysis is done to study the response of a floating granular piled raft based on the elastic continuum approach. The mathematical study is carried out for the comparative analysis of settlement of granular piled raft to rigid raft only and granular pile alone with variation of relative stiffness of GP, relative size of raft, and relative length of floating GP. The overall response of a granular pile with the rigid raft on top is presented in terms of settlement influence factor (SIF) for, viz. granular piled raft, rigid raft only, and pile alone. On the basis of findings, design charts are prepared to facilitate the design procedure.