This study investigated the load-settlement mechanism of embedded piled raft foundations in sandy soils (ranging from loose to low medium dense sands) under vertically uniform loads through a series of three-dimensional finite element analyses. The foundation model comprises a square concrete raft, varying in width from 16 to 36 m, and embedded at depths of 8 and 12 m from the ground surface. Concrete piles with a diameter of 1 m and lengths of 20 m and 30 m were installed beneath the raft. The foundation was located in homogeneous sands with shear wave velocities ranging from 150 to 210 m/s. Consequently, the modulus of subgrade reaction of the subsoil and the coefficient of pile reaction were both reported. This study examined and presented alternative dimensionless measures of pile displacements, pile reactions, and corresponding coefficients of pile reactions to facilitate hand calculations. Optimized correlations were suggested using box plots and regression analyses for the dimensionless measures with the non-dimensional design parameters of the foundation. Upon verifying the proposed suggestions on a sample example, we conclude that the proposed method offers a preliminary calculation tool for the design of piled raft foundation design in the studied sands.
