Comparative study of Y-shaped and circular floating piles in consolidating clay
Comparative study of Y-shaped and circular floating piles in consolidating clay
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Y形与圆形浮桩固结粘土对比研究
DOI：
10.1139/cgj-2015-0634
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发表时间：
2016-09-01
影响因子：
3.6
通讯作者：
Ding, Xuanming
中科院分区：
文献类型：
--
作者：
Lv, Yaru;Ng, Charles W. W.;Ding, Xuanming
虽然工程师们经常利用桩的几何形状来提高桩的轴向承载力，但对固结粘土中浮桩的几何效应仍然没有完全了解。本文通过离心模型试验，研究了Y形桩和圆形桩在竖向荷载和竖向荷载共同作用下的动力响应。考虑弹塑性滑移，进行了三维数值反分析。Y形桩和圆形桩产生相似的下拉阻力，但Y形桩上产生的拖曳荷载大于圆形桩上产生的拖曳荷载。随着轴力的增加，桩身中性面沿非线性路径沿着向上移动，其中Y形桩的倾斜度较平缓。Y形桩的极限承载力是圆形桩的1.73倍。Y形桩和圆形桩上的拖曳荷载最终分别在相应极限桩承载力的约0.56倍和0.83倍处消除。Y形桩的三个翼缘“吊起”与桩身一起沉降的邻近土壤。竖向不均匀陷土的横向范围随轴向荷载的增大而减小。虽然Y形桩和圆形桩的正常使用极限状态相似，但Y形桩在承载力方面具有优势。
Although engineers often make use of pile geometry to improve the axial load capacity of piles, geometrical effects on floating piles in consolidating clay are still not fully understood. This paper reports two centrifuge model tests to investigate the responses of a Y-shaped pile and a circular pile subjected to an induced dragload and applied axial loads. Three-dimensional numerical back-analyses were performed considering the elastoplastic slip. The Y-shaped and circular piles developed similar downdrag, but the dragload induced on the Y-shaped pile was larger than that induced on the circular pile. As the axial load increased, the neutral plane shifted upward along a nonlinear path, of which the gradient of the Y-shaped pile was gentler. The ultimate bearing capacity of the Y-shaped pile was 1.73 times that of the circular pile. The dragload on the Y-shaped and circular piles was eventually eliminated at approximately 0.56 and 0.83 times the corresponding ultimate pile capacities, respectively. Three flanges of the Y-shaped pile "hung-up" adjacent soil that settled together with the pile shaft. The lateral extent of vertically nonuniform trapped soil decreased with increasing axial load. Even though the Y-shaped and circular piles encountered a similar serviceability limit state, Y-shaped pile had advantages in bearing capacity.