砂土中大直径单桩水平受荷离心模型试验

朱斌; 熊根; 刘晋超; 孙永鑫; 陈仁朋

砂土中大直径单桩水平受荷离心模型试验 English Version

朱斌^{1, 2},
熊根^{1, 2},
刘晋超³,
孙永鑫^{1, 2},
陈仁朋^{1, 2}

1. 软弱土与环境土工教育部重点实验室（浙江大学）,浙江杭州 310058; 2. 浙江大学岩土工程研究所,浙江杭州 310058; 3. 广东省电力设计研究院,广东广州 510000

基金项目: 国家自然科学基金项目（51179169,50979097）

详细信息

作者简介:
朱斌(1977- )，男，教授、博士生导师，主要从事海洋岩土工程等方面的教学和科研。E-mail：binzhu@zju.edu.cn。

中图分类号: TU43
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出版历程
- 收稿日期: 2013-02-24
- 发布日期: 2013-10-19

Centrifuge modelling of a large-diameter single pile under lateral loads in sand

ZHU Bin^{1, 2},
XIONG Gen^{1, 2},
LIU Jin-chao³,
SUN Yong-xin^{1, 2},
CHEN Ren-peng^{1, 2}

1. MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou 310058, China; 2. Institute of Geotechnical Engineering, Zhejiang University, Hangzhou 310058, China; 3. Guangdong Electric Power Design Institute, Guangzhou 510000, China

摘要

摘要: 大直径桩基在海洋工程中已越来越广泛应用。针对目前API规范p-y曲线对水平受荷大直径单桩的不适用性,通过离心模型试验研究了砂性土中大直径单桩分别在水平静力和循环荷载作用下的受力和变形特性。验证了通过实测桩身弯矩推算桩身变形和桩周土反力的有效性,分别获得了干砂和饱和砂的大直径单桩水平静力p-y曲线。在修正p-y曲线初始刚度的基础上,采用双曲线型p-y曲线分析了水平受荷大直径单桩的内力和变形。揭示了水平单向循环荷载下大直径单桩的桩身变形及内力变化特性,试验结果显示桩身变形和最大弯矩近似与循环次数的对数线性相关。最后,由各循环次数下的桩身弯矩获得了大直径单桩水平循环p-y曲线,提出了循环应力比相关的p-y曲线循环弱化因子,以及相应的桩基变形累积和内力变化分析方法。
- 离心模型试验 /
- 大直径 /
- 桩 /
- 水平受荷 /
- 砂土
Abstract: Large-diameter pile foundations are more and more widely used in ocean engineering. The current p-ycurve approach given in the API code cannot be used for large-diameter piles subjected to lateral loads. To deal with this problem, the behaviors of large-diameter piles in sand under lateral static and cyclic loadings are investigated based on several centrifugal model tests. The calculation approach for lateral displacement of pile shaft and soil reaction force using the measured bending moment of the pile shaft is verified. Static p-ycurves of large-diameter piles in both dry and saturated sands are also obtained. By modifying the initial stiffness of p-ycurves, a series of hyperbolic p-ycurves are adopted to compute internal force and deformation of large-diameter piles. The change of deformation and internal force of large-diameter pile foundations under one-way cyclic loading is released. The test results show that the head displacement and the maximum moment of pile shaft almost linearly increase logarithmically with number of cycles. Finally the cyclic p-ycurves of large-diameter pile foundations according to bending moment of the pile shaft in each cycle are obtained. A cyclic degradation factor related to the cyclic stress ratio and a corresponding approach for analyzing cyclic deformation and internal force of the pile shaft are proposed.
- centrifugal model test /
- large diameter /
- pile /
- lateral load /
- sand

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参考文献(21)

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