Analysis of sinking behavior in open-ended pipe piles for marine structures: Jacking vs. hammer-driven methods

To investigate the sinking mechanism of open-ended pipe piles under jacking and hammer pile sinking methods, this study conducted indoor model tests using double-wall open-ended model piles. The experimental results reveal that, during the hammer-driven sinking process of open-ended pipe piles, the number of hammer drives increases with the depth of pile sinking. This trend underscores the importance of understanding energy transfer during pile installation, particularly in marine environments where dynamic conditions can significantly affect performance. Upon reaching the sand layer, the number of hammer drives experiences a rapid increase, leading to a significant reduction in penetration. Compared to the jacking pile sinking method, the hammer-driven pile sinking results in a greater formation height of soil plugs, with the soil plug height increasing with higher impact energy. Throughout the pile sinking process, the variation in radial soil pressure diminishes as the radial distance from the pile increases. Additionally, the variation in radial soil pressure is more significant in jacking piles compared to hammer-driven piles. Understanding these pressure distributions is essential for predicting potential failure modes and ensuring the reliability of structures subjected to dynamic loads.