Flexural behavior on a novel socket joint connecting precast piles: A full-size experimental evaluation

Precast pile technology is gaining popularity in the construction industry, particularly for deep foundation pits (DFPs). However, challenges persist in achieving optimal force performance and construction efficiency in connecting methods. In this study, we present a novel socket joint design including first and second level connectors, enabling robust connections and efficient installation. A comprehensive large-scale experiment unraveled the joint flexural behavior, exposing an eastic stage dominating over 70% of the process. During loading, bolt pin slippage induced extrusion on the upper and lower flange slabs, leading to yielding and substantial deflection, ultimately surpassing the load-bearing capacity of the joint. Lower bolt pins exhibited apparent shear failure, attributed to their interaction with the lower flange slab. Based on experimental results, the calculation for flexural performance is presented. Furthermore, finite element analysis elucidated the internal forces and deformation characteristics at various stages. Stress redistribution in and around the pins in the tension zone of the joint is an important aspect of joint load failure. These findings highlight the potential of the socket joint in overcoming limitations associated with conventional connecting methods in precast pile technology.