Structural behaviour of precast prestressed H-shaped ultra-high performance concrete (UHPC) pile with steel spliced joint

Abstract

Issues related to pile driving, prestressing of concrete piles, and exposure to environmental conditions in steel and concrete piles negatively affect the service life of bridges. This has prompted interest in finding alternative materials for pile foundations to achieve a minimum 75-year service life with minimal maintenance. Ultra-high performance concrete (UHPC) is a promising candidate due to its exceptional strength and durability properties, offering potential improvements in drivability, and structural and geotechnical performances of the piles. In this study, a precast prestressed UHPC pile with a new geometry was investigated and its bending and shear strengths were evaluated through experimental tests. Additionally, the moment-curvature relationship of this pile under different values of axial compression forces is determined using the fiber technique method. Additionally, this study focused on the splice joints designed for the UHPC pile described above. This study also employed the finite element method (FEM) to evaluate the behavior of piles under direct tensile forces and to assess the performance of piles with different sizes of splices. Findings revealed that the piles in this study provided higher capacity compared to previously tested UHPC piles. Piles exhibited superior performance in terms of crack width control. The maximum shear load and bending moment of all specimens exceeded the values recommended by design guidelines.