Long term effect of vertical and lateral loads on piled raft foundations: A case study

In this study, numerical analyses of connected and disconnected piled- raft foundations (PRFs) comprising of single pile, 2×1, 3×1, 2×2, 3×2, 3×3 and 5×5 pile groups subjected to different lateral loads with a constant vertical load have been carried out by a three- dimensional finite element analysis. Results from the present analysis have been validated with reported field studies considering vertical load and reported experimental studies considering lateral load. The reported multilayered sub-soil profile has been considered for the analysis. Parametric studies in terms of effect of variation in pile length (L/d=20, 30, 39), spacing of piles in the pile group (S/d=3, 5, 6), number of piles, thickness of raft (0.5m, 1.2m, 2m), variation of axial force, excess pore water pressure, bending moment and shear force along depth of piles for connected and disconnected PRFs have been discussed for a time period of 20 years. The horizontal connected piled- raft coefficients have been determined corresponding to the lateral deflections. Generalised equation has been predicted for the horizontal connected PRF coefficient.