Effect of interior restraint plate on the axial resistance of open-ended pipe pile using centrifuge modeling

Abstract

Wind energy is a promising renewable resource with vast potential to provide a clean and sustainable global electricity supply. Although pipe pile with interior restraint plate (PPIRP) exhibits significant advantages in bearing performance over open-ended pipe pile (OEPP), comprehensive studies on their bearing characteristics remain limited. This study investigates the compressive and pullout behaviors of OEPP and PPIRP. The research comprises compressive and tensile centrifuge tests of one OEPP and three PPIRPs. Based on recorded load response and soil pressure data, the vertical bearing characteristics of pile foundations are analyzed. The results reveal that the inclusion of an interior restraint plate (IRP) enhances both the compressive bearing capacity and the unit area pullout capacity of OEPP. Furthermore, a soil pressure distribution model at the pile tip is proposed to elucidate the IRP working mechanism. The IRP does not increase the earth pressure near the center of the pile tip, but it enhances the distribution of earth pressure near the pile shaft. A simplified method for evaluating the pile vertical bearing capacity based on the external pullout friction is also proposed. The findings of this study provide valuable insights for optimizing the design and performance of pile foundations.