Experimental and numerical analysis of single piled raft unit in unconventional soil

This article explores the behaviour of single piled raft units and their components (raft and pile) under axial compression through experimental and numerical analysis. Prototypes were constructed and subjected to static load tests in silty-clayey sand subsoil. Piles were instrumented at different depths to analyse load distribution and transfer, showing improved load transfer along the pile length. Compared to single piles and rafts, single piled raft units in tropical soil exhibited approximately 10% and 62% higher bearing capacity, respectively. Experimental data validated a numerical model, indicating a stress bulb behaviour reaching 1.5 to 2 times the raft diameter in the pile region, reducing skin friction along the shaft. The pile-raft connection enhanced structural rigidity, increasing bearing capacity and reducing settlements. These findings underscore the significance of pile-raft interaction for foundation performance and efficiency under axial compression.