Canadian Geotechnical Journal, Ahead of Print.
This study investigated the performance of screw piles under uplift. The screw piles were installed in sand in the laboratory and uplifted to evaluate the effects of the screw thread pitch and relative density of sand on the pile uplift capacity. The uplift capacity was compared with that of the shaft pile using the digital image correlation technique. Discrete element modelling was used to further examine the load-sharing characteristics, axial force, and shaft friction of the screw pile. The results suggest that the screw pile outperformed the shaft pile in terms of uplift capacity, pile–sand interactions, and load transfer. The improved uplift performance is attributed to the screw threads reaching out to a larger volume of sand particles to resist the uplift. An equation was also proposed to determine the uplift capacity.

中文翻译：

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干砂中螺旋桩举升模型及数值分析

加拿大岩土工程杂志，印刷前。
本研究调查了螺旋桩在隆起作用下的性能。在实验室将螺旋桩安装在砂土中并进行举升，评价螺距和砂土相对密度对桩的抗拔能力的影响。使用数字图像相关技术将抗拔能力与竖井桩的抗拔能力进行比较。采用离散元建模进一步检查螺旋桩的荷载分配特性、轴力和轴摩擦力。结果表明，螺旋桩在抗拔能力、桩-砂相互作用和荷载传递方面优于竖井桩。提升性能的提高归因于螺纹接触到更大体积的沙粒以抵抗提升。还提出了一个方程来确定举升能力。