Application of Image Analysis to Investigate the Scale Effect of Open Driven Piles Under Different Infill Conditions

Hollow piles with open ends are used in many civil engineering applications by virtue of its less mass density and easy drivability. Because of the soil plug formed at the ends of the open-ended hollow pile, the bearing capacity of such piles is evaluated similar to solid piles. Field tests on pile can be used to determine its load carrying capacity but it fails to predict the crushing and densification of soils that happens at the pile tip. In the present work, PIV technique is used to assess plugging effect of pile in cohesion-less soil prepared at different densities. A steel tank of dimensions 450 mm × 200 mm in plan, and 450 mm deep is used for performing experiments. Wood’s scaling law is used to scale the model sections and three different scaling factors of 10, 5.7, and 4.5 are chosen for the study. Piles are driven using impact loads, and this process is captured through digital camera. Later the images are analysed to understand shear strain and volumetric strain developed around pile soil interface. From the experimental study, it is observed that the extent of soil plugging is dependent upon the pile diameter and it influences the pile capacity as well.