粉质黏土中单桩竖向承载力的离心模型试验研究

发布时间：2018-11-09 13:24

【摘要】：桩基础研究的核心问题是桩承载力和桩-土相互作用,包括桩周土的变形和饱和土中孔隙水压力的变化。通过离心模型试验的方法,利用竖向压桩设备把桩压入土体,研究饱和及非饱和粉质黏土中单桩的竖向承载力,以及加载过程中桩周土体的变形和孔隙水压力的变化。粉质黏土饱和后,桩基的承载特性表现出软化的特点,且桩基的承载能力比非饱和粉质黏土中的桩基小,非饱和粉质黏土的压桩试验中桩基没有出现明显的极限承载力。桩基的加载特性与桩周土的变形响应具有显著的相关性,桩的加载过程对桩周土体变形的影响有一定范围,超过这个范围,土体的变形可以忽略不计。饱和粉质黏土中桩基的加载对桩周土体孔压的变化也有一定的影响范围,与桩周土体的变形范围体现出类似的规律。距离桩较近时,桩周土的变形较大;距离桩越远,土体的变形受到桩的影响越小。
[Abstract]:The core problem of pile foundation research is pile bearing capacity and pile-soil interaction, including the deformation of soil around pile and the change of pore water pressure in saturated soil. The vertical bearing capacity of a single pile in saturated and unsaturated silty clay and the deformation of soil around the pile and the variation of pore water pressure during loading are studied by means of centrifugal model test. When the silty clay is saturated, the bearing capacity of the pile foundation is softened, and the bearing capacity of the pile foundation is smaller than that of the pile foundation in the unsaturated silty clay soil, and there is no obvious ultimate bearing capacity of the pile foundation in the piling test of the unsaturated silty clay soil. There is a significant correlation between the load characteristics of pile foundation and the deformation response of soil around the pile. The effect of pile loading process on the deformation of soil around pile has a certain range, beyond which the deformation of soil can be ignored. The loading of pile foundation in saturated silty clay also has a certain influence on the change of pore pressure of the soil around the pile, which is similar to the deformation range of the soil around the pile. When the pile is close to the pile, the deformation of the soil around the pile is larger, and the further away from the pile, the smaller the deformation of the soil is affected by the pile.
【作者单位】：清华大学水沙科学与水利水电工程国家重点实验室;
【基金】：国家自然科学基金(No.51129902)
【分类号】：TU473.1

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