Stress State Analysis of the Soil Plug of Open-Ended Piles during Impact Driving Using Particle Flow Code (PFC)

Abstract

The increasing demand for energy and industrial development necessitates the construction of large-scale structures, often in previously undeveloped areas. Pile foundations, particularly open-ended piles (OEPs), are extensively used in such projects due to their drivability and structural integrity. This research focuses on the unique plugging effect in OEPs, where soil enters the pile during installation, forming a soil plug that significantly contributes to the pile’s static resistance. A significant challenge in OEP applications is the uncertainty in internal stress states and bearing capacity due to the dynamic nature of impact driving in sands. Current standards assume that the inner skin friction equals the outer skin friction along the entire soil plug length, a conservative approach lacking in consideration of the actual stress states. Utilizing the Particle Flow Code (PFC) software, this research aims to analyze the internal stress conditions within the soil plug during impact driving, providing a more accurate prediction of OEP behavior under various conditions. The study’s findings, validated against experimental results, enhance the understanding of soil–pile interactions, contributing to the development of improved design methodologies for open-ended piles.

Keywords

• open-ended piles
• soil plug
• impact driving
• stress state
• numerical analysis
• PFC