（1 浙江工业大学建筑工程学院，杭州 310032；    2 浙江大学建筑设计研究院，杭州 310027）

［摘要］对一个双盘模型支盘桩在非饱和粉土中进行了5次循环加载卸载试验。试验证明：支盘桩在小于其极限承载力约0.75倍的重复荷载作用下变形增加很小，工作性能十分稳定；支盘桩与普通等直径桩相比，其承载力和抗变形能力十分优越；支盘桩的荷载传递机理十分复杂，盘附近土体对桩周的摩擦阻力在不同荷载作用下有时为正有时为负；当两盘的间距小于2D（D为盘直径）时，桩周的摩擦力对桩的承载力贡献很小，在每次重复荷载作用下，盘间土体都会经历加压和卸压的过程，卸载后土体会建立新的平衡和物理性质工作状态。研究表明，支盘桩应用于桥梁等承受重复荷载的结构是可行的。

［关键词］支盘桩；模型试验；重复荷载；荷载传递机理

Test study on model piles with branches and plates under repeatedly load

Meng Fanli 1, Wu Jie 2, Lu Chengyuan 1

(1 College of Civil Engineering and Architecture, Zhejiang University of Technology, Hangzhou 310032, China;

 2 Architectural Design and Research Institute of Zhejiang University, Hangzhou 310027, China)

Abstract:A model test was done to analyze the bearing capacity behavior and deformation behavior of the piles with branches and plates under repeated load. It is proved that: the deformation increment of the pile is small and working behavior is very stable when the load is less than 3/4 of limit bearing capacity; the bearing capacity and resistance of deformation are better compared with equal diameter pile; the load transfer mechanism of the pile with branches and plates is really complex, and the skin friction of the silt around the plates is positive or minus under different loads; when the distance of plates is less than 2D, the contribution of skin friction to bearing capacity is very small, and under each repeated loading, the silt between plates would go through the process of load bearing and load shedding. It is showed that pile with branches and plates could be used in bridge engineering  under repeated load.

Keywords:pile with branches and plates; model test; repeated load; loading transfer mechanism

*浙江省自然科学基金项目（502117）。