Investigation of the Behavior of Piled Raft Foundations in Sand by Numerical Modeling

Abstract

This paper is on 3-D analysis of piled raft foundations on sand. The numerical analysis was carried out with three typical load intensities of the serviceability load. Further, extensive parametric studies were carried out with the variables pile spacing, number of piles, pile diameter, raft dimension ratio, and raft thickness. The maximum settlement of the piled rafts depends on the pile spacing and the number of piles; while the raft thickness does not have a significant effect. In all cases, the normalized settlement recorded is mostly less than 2% of the raft width and the maximum value was noted for the 8x27m piled raft. The increase in raft thickness reduces the differential settlement in the foundations. The raft-soil stiffness (Krs) is shown to influence the differential settlement and has the largest influence. The performance of piled raft in sandy soil condition is assessed and general conclusions are also made.