循环荷载下冻土桩基力学特性研究

发布时间：2018-05-22 13:46

本文选题：冻土 + 桩基　；参考：《铁道科学与工程学报》2017年10期

【摘要】：通过给冻土单桩模型上端施加循环荷载,分析循环荷载幅值、频率及冻土温度的变化对桩身应变、桩身轴力、桩侧冻结应力以及桩土相对位移的影响规律,开展循环荷载作用下冻土桩基力学特性的研究。研究结果表明:桩身应变随着加载时间先增加后稳定,且低温环境和小荷载条件下更有利于桩身应变的稳定;桩身的应变随荷载幅值及频率的增加而变大,随温度的降低而减小;桩身轴力沿着桩深不断减小,是由于桩侧土体使桩从上部开始受力;低温环境下桩身轴力相对较小,这是冻土地区桩基稳定的有利条件;桩侧冻结应力首先从桩基的上端发挥作用,并逐渐向下传递,分别增大荷载幅值、频率及降低温度都会增强桩侧冻结应力;桩土相对位移受荷载幅值、频率及温度的影响明显,频率能够影响桩土的承载模式。
[Abstract]:By applying cyclic load to the upper end of the single pile model, the effects of cyclic load amplitude, frequency and frozen soil temperature on the strain, axial force, freezing stress and relative displacement of the pile are analyzed. The mechanical properties of frozen soil pile foundation under cyclic load are studied. The results show that the strain of pile body increases first and then stabilizes with loading time, and the strain of pile body increases with the increase of load amplitude and frequency, and is more favorable to the stability of pile body strain under low temperature and low load conditions. With the decrease of temperature, the axial force of pile body decreases continuously along the pile depth, which is due to the pile-side soil to force the pile from the upper part, the axial force of pile body is relatively small at low temperature, which is the favorable condition for the stability of pile foundation in frozen soil area. The freezing stress of the pile side plays an important role from the top of the pile foundation, and gradually transfers down the pile foundation, increasing the load amplitude, increasing the frequency and decreasing the temperature will enhance the freezing stress of the pile side, and the relative displacement of pile and soil is affected by the load amplitude, frequency and temperature. The frequency can affect the bearing mode of pile and soil.
【作者单位】：兰州交通大学土木工程学院;商丘学院土木工程学院;
【基金】：中国铁路总公司科技研究开发计划项目(2015G005-C)
【分类号】：U443.15

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