Parametric analysis and performance evaluation of piled raft foundations: comparing hollow and conventional systems

Piled raft foundations (PRF) are commonly used in areas with unstable or weak soil conditions, where traditional foundations may not provide adequate support for tall buildings and large structures. Previous studies on PRF assumed that the connecting piles were solid, and the concept of hollow PRF remained unexplored. Nonetheless, the piles that are firmly attached to the raft in this type of foundation system can be regarded as having hollow cross-sections for cost-efficiency. The present research undertakes a comparative analysis of hollow and solid PRF, focusing on square-cross-section piles using finite element analysis (FEA) through Abaqus three-dimensional (3D) software. In this study purely vertical loading up to 1.0 MPa is considered for thorough analysis. In the case of a hollow PRF, the piles are typically hollow, and during the installation process, the empty spaces within the hollow piles in a combined PRF are typically filled with soil material from the surrounding foundation area. As a result, it has found that the pressure settlement behaviour of a hollow PRF with an outer diameter of 1.0 m and an inner diameter of 0.5 m exhibits a similar tendency to that of a solid PRF with the same outer diameter. In this manner hollow PRF represent the more suitable and cost-effective foundation type. This process enhances both strength and stability, while also reducing the amount of material required for casting the foundation.