Analysis of the Load-Sharing Behavior of Disconnected Piled Raft Foundation Using Non-Linear Soil-Structure Interaction

The disconnected piled raft (DPR) foundation system is a structural system where the raft and piles are not directly connected. Instead, the space between them is filled with gravel and geogrid layers to create a more even pressure distribution and reduce differential settlement. This research paper investigates the interaction between the raft, piles, and soil in saturated fat clay using 3D finite element analyses. The study explores various aspects, such as the effects of different pile configurations, raft-soil gaps, and stiffness on load distribution and settlement. The analysis also focuses on the structural response of the piles, including axial forces, bending moments, and internal stress. The study models the piles as embedded beam elements and the concrete slab as solid elements. The soil behavior is simulated using the hardening soil small-strain (HSss) model, considering the Mohr-Coulomb failure criterion, stiffness dependence, small-strain behavior, and nonlinear soil stiffness. By comparing the finite element analysis results with those from a simplified method, the study provides insights into the accuracy and effectiveness of the proposed modeling approach for evaluating the DPR system.