An Investigation to Evaluate the Performance of Connected and Disconnected Piled Raft Systems Under Varying Soil Conditions

The piled raft foundation (PRF) combines the bearing capacities of piles, rafts, and soil into a composite structure. This study evaluated the performance of different piled raft configurations, including unpiled raft (UPR), disconnected piled raft (DPR), vertical piled raft (VPR), and battered piled raft (BPR), on granular soils. The experiments were conducted across varying soil densities, from loose to dense. The results reveal that the BPR configuration exhibited the highest load-bearing capacity among all systems. BPR outperformed VPR by 11.5% in dense soil and 23.3% in loose soil. Furthermore, the bearing capacities of UPR, DPR, VPR, and BPR increased by 328.6%, 722.3%, 502.7%, and 442.6%, respectively, in dense soil compared to loose soil. Connected piled rafts (CPR) further enhanced load distribution and stability, achieving a 6.1% higher load-bearing capacity in dense soils and 15.9% in loose soils compared to DPR. The analysis of axial load and skin friction distribution along pile length indicated that BPR systems provided the best resistance against both vertical and lateral loads, leading to reduced settlement and improved load transfer efficiency. Overall, the BPR system demonstrated optimal performance across varied soil conditions, while CPR configurations improved settlement control and load distribution.