Energy Intensity and Uplift Load Resistance of Novel Hybrid Pile, Driven with Additional Compaction: Comparative Field Study

The article presents the results of an experimental study on driven reinforced concrete piles with hybrid shaft, which incorporates several wedge-shaped elements with inclined side faces. A technology for the installing of these piles, involving the addition of loose materials to enhance soil compaction, is herein proposed. Field experiments were conducted to determine the energy intensity of driving and the uplift load resistance of these piles. It was found that the energy intensity of a driving hybrid pile with loose materials addition is 1.4–3.5 times greater compared to conventional driven piles. However, the uplift bearing capacity was 1.5–4.4 times higher than that of piles with a traditional shape. The efficiency of the experimental piles is attributed to an increase in the volume of wedge-shaped elements on the pile shaft and the incorporation of loose materials, such as gravel and sand. The uplift capacity of hybrid shaft piles improves with the increasing volume of the aforementioned parameters. The obtained correlation dependencies enable a reliable calculation of the energy intensity and uplift resistance of hybrid shaft piles installed with the addition of loose materials. These findings hold significant practical importance for foundation design using piles with non-traditional shaft shapes in variant design assessments.