循环压拔荷载作用下桩基础模型试验研究
Experimental study on pile foundation models under cyclic compression and tension loads
朱武卫 1张树筱 2刘彤 3刘义 1李哲 2刘路路 4邵登峰 2马锡洋2
作者信息
- 1. 陕西省建筑科学研究院,陕西西安 710000
- 2. 长安大学公路学院,陕西西安 710064
- 3. 中山大学土木工程学院,广东广州 510275
- 4. 中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州 221116
- 折叠
摘要
随着大型建筑物不断兴起,桩基础作为西部地区基础常用形式之一,在承受上拔力作用时发挥着不可替代的作用.为了探明桩基础在循环荷载作用下的承载特性,在黄土高原区某典型黄土地基上,对单桩进行抗拔试验、循环压拔试验和循环抗拔试验.重点分析循环压拔加载路径下桩顶轴向位移和桩侧摩阻力的分布规律,阐述桩基承载力在不同循环次数以及循环荷载时的变化规律.结果表明:循环荷载和循环次数都是影响桩顶轴向位移变化的重要因素,并引入弱化因子来定量描述循环次数的影响;荷载越大,桩侧摩阻力越大,循环荷载下桩侧摩阻力整体呈下降趋势;压拔循环加载会在一定程度上减少对桩土之间接触的破坏,桩基承载力的损失也会更少,试验对竖向循环压拔荷载作用下的桩基础承载能力研究具有深刻的工程实践意义.
Abstract
With the continuous rise of large-scale buildings,pile foundation,as one of the commonly used foundation forms in the western region,plays an irreplaceable role in bearing uplift forces.In order to study the bearing characteristics of pile foundation under cyclic loading,single pile pull-out tests,cyclic press-pull tests,and cyclic pull-out tests were conducted on a typical loess foundation in the Loess Plateau area.The study analyzed the distribution patterns of axial displacement at the pile top and the side friction strength of the pile under cyclic compression and pull-out loading paths.It elucidated the variations in pile bearing capacity under different numbers of cycles and varying cyclic loading magnitudes.The results showed that the amplitude of cyclic loading and the number of cycles were important factors affecting the change of axial displacement at the top of the pile,and a weakening coefficient parameter was introduced to quantitatively describe the influence of the number of cycles.The greater the load,the higher the side friction of the pile,but overall.the side friction tended to decrease under cyclic loads.Cyclic compression and pullout loading could reduce the damage to the contact between the pile and soil to a certain extent,resulting in less loss of pile foundation bearing capacity.This study has profound engineering significance for the research on the bearing capacity of pile foundation under vertical cyclic compression and pull-out loads.
关键词
抗拔桩/循环荷载/轴向位移/侧摩阻力/桩基承载力Key words
uplift pile/cyclic loading/axial displacement/side friction resistance/bearing capacity of pile foundation引用本文复制引用
基金项目
江苏省卓越博士后计划(2022ZB529)
江苏省自然科学基金青年基金(BK20221136)
陕西省重点研发计划(2021SF-459)
出版年
2024
国家科技期刊平台
NSTL
万方数据