关键词: 根式抗拔桩, 上拔荷载, 模型试验, 承载力, 侧摩阻力

Abstract: Rooted uplift pile foundation is a new type of foundation with variable cross-section with concrete roots jacking in the sidewall of caisson. Reasonable arrangement of roots could reduce construction cost while improving foundation’s bearing capacity. In an aim of enhancing the efficiency and reliability of applying rooted uplift piles in engineering, we compared the bearing capacity—to be specific, uplift displacement, axial force of pile shaft, and lateral frictional resistance—of ordinary uplift pile and rooted uplift pile in sand under different levels of vertical uplift load through model test. Results revealed that the bearing capacity of rooted uplift pile increased by 57% compared with that of ordinary uplift pile; the axial force of pile shaft changed significantly at roots; the lateral frictional resistance of the pile was transmitted from top to bottom, and reached the extreme value near the roots. In addition, setting the roots as close as possible to the bottom of pile is an effective way to improve the bearing capacity of rooted uplift pile in the premise of ensuring the strength of root not damaged and the installation of root convenient.

Key words: root uplift pile foundation, uplift loading, model test, bearing capacity, lateral frictional resistance