Assessment of Scaling Effects on Plugging of Driven Piles Using Image Analysis

Abstract

In recent years, open-ended steel pipe piles have been used in the foundations of urban and coastal structures such as long-span bridges, harbor terminals, and offshore wind power structures. It is found that pile capacity depends directly on pile dimensions and plugging phenomenon, especially in the case of open-ended driven piles. The present study investigates the effect of variation of pile cross sections and plugging behavior through image analysis. Three different scaling factors of 10, 5.7, and 4.5 are chosen for selecting pile dimensions and aluminum piles are modeled using Wood’s scaling law. Later, modeled piles are subjected to impact loads replicating energy of standard penetration test (SPT) in sandy soil for different infill densities. The experimental process is captured through a digital camera and later images are analyzed through Geo PIV software to understand displacement behavior and strain path. It is found that, with an increase in pile diameter, there is a decrease in plugging and an increase in shear strain contour around the pile tip. It is also seen that shear strain concentration zones are developed around the annular area of a larger diameter pile tip region.