刚性桩复合地基桩顶埋入式垫层机理分析

发布时间：2019-05-23 03:46

【摘要】：基于Meyerhof理论,提出了改进的桩顶埋入式垫层,推导出垫层极限桩土应力比的计算公式,并对桩顶埋入式垫层的作用机理进行了分析。研究发现:桩顶埋入式垫层可减少桩顶向上刺入量和地基沉降量,极限桩土应力比随刺入量的增加和垫层内摩擦角的增大而增大。提出了考虑桩顶垫层厚度及桩距影响的极限桩土应力比修正计算方法,推导了相应的计算公式和计算曲线,可供实际工程应用时查询。研究表明:修正后的埋入式垫层极限桩土应力比随桩顶预埋深度与垫层厚度之比的增加而增大,随桩距的增加而减小。通过算例分析,认为桩顶埋入式垫层具有垫层厚度和预埋深度可双向调节的优点,可用于调节复合地基应力和控制差异沉降,并可作为高层建筑地基变刚度调平设计的手段。
[Abstract]:Based on Meyerhof theory, an improved pile top embedded cushion is put forward, the formula for calculating the stress ratio of ultimate pile to soil in cushion is derived, and the action mechanism of pile top embedded cushion is analyzed. It is found that the pile top embedded cushion can reduce the pile top penetration and foundation settlement, and the limit pile-soil stress ratio increases with the increase of penetration and friction angle within the cushion. A modified calculation method of limit pile-soil stress ratio considering the influence of pile top cushion thickness and pile distance is put forward, and the corresponding calculation formula and calculation curve are derived, which can be used for practical engineering application. The results show that the modified limit pile-soil stress ratio of embedded cushion increases with the increase of the ratio of pile top buried depth to cushion thickness, and decreases with the increase of pile distance. Through the analysis of an example, it is considered that the embedded cushion at the top of the pile has the advantages of bidirectional adjustment of cushion thickness and embedded depth, which can be used to adjust the stress of composite foundation and control the differential settlement, and can be used as a means of variable stiffness leveling design of high-rise building foundation.
【作者单位】：江苏省建筑设计研究院有限公司;东南大学土木工程学院;
【基金】：国家重点基础研究发展计划(973计划)项目(2013CB036304) 江苏省建筑设计研究院有限公司科研项目(B2015-003)
【分类号】：TU472.2

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