A COMPARATIVE STUDY ON BEHAVIOR OF BUCKET PILE IN SAND ACCORDING TO INSTALLATION METHODS-Paper

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The study compares bucket piles installed in sand by suction and mechanical jacking, using model tests to assess vertical and horizontal pull-out resistance and changes in soil conditions measured with a miniature cone penetrometer.<br /><br />Jacked piles showed substantially greater vertical uplift resistance—about three times that of suction-installed piles at the start of testing. Suction-installed piles also had lower horizontal capacity and stiffness, although the reported reductions differ between the abstract and detailed results. Some uplift resistance appeared to recover after 20 hours, suggesting that soil relaxation or aging can partly offset installation-related disturbance.<br /><br />Cone penetration tests showed lower resistance inside and near the tip of suction-installed piles. Internal cone resistance was approximately 35–40% lower than for jacked piles, while resistance near the pile tip was about one-third lower. The authors attribute these differences to seepage caused by suction: upward flow inside the pile reduces effective stress and disturbs the soil, whereas downward flow outside may have a smaller effect.<br /><br />Overall, installation method significantly affects bucket-pile behavior in sand. The authors conclude that suction-related changes in effective stress and soil condition should be considered when designing bucket foundations. Further testing under varied soil densities, loading locations, and cone positions is recommended.

Keywords

bucket piles

sand

suction installation

mechanical jacking

pull-out resistance

uplift resistance

horizontal capacity

cone penetration test

effective stress

soil disturbance