冲钻孔灌注桩承载机制和承载力解答研究

发布时间：2018-12-27 15:13

【摘要】：首先对快速和慢速灌注混凝土的情况及其与承载力关系的力学机制进行分析,认为在其他条件相同情况下,快速灌注混凝土情况对应于桩基础承载力的上界,实际施工的混凝土灌注速度介于研究中定义的快与慢之间,所以其承载力也介于这两者之间。其次,对于快速灌注混凝土的情况,桩孔壁土体受处于流态的混凝土法向分布压力作用,其凝固并达到设计强度后的承载性能与法向分布压力大小直接相关,并以此定义桩土作用的力学模型位移和应力边界条件和求解方法。最后,应用变分理论求解桩土作用在桩周土体中形成的应力场和界面的法向压力,求解桩土作用界面上的极限摩阻力,从而求得冲钻孔灌注桩的理论极限承载力和桩身轴力,并结合现有超长灌注桩的桩身轴力实测资料,验证本文分析方法和求解结果的合理性。
[Abstract]:Firstly, the mechanical mechanism of the relationship between the rapid and slow pouring concrete and its bearing capacity is analyzed. It is considered that under the same conditions, the condition of the rapid pouring concrete corresponds to the upper limit of the bearing capacity of the pile foundation. The concrete pouring speed of actual construction is between the speed and the slowness defined in the study, so the bearing capacity of concrete is between the two. Secondly, for the case of rapid pouring concrete, the pile wall soil is subjected to the normal distribution pressure of concrete in the flow state, and the bearing capacity after solidification and reaching the design strength is directly related to the magnitude of the normal distribution pressure. The displacement and stress boundary conditions and the solution method of the pile-soil interaction are defined. Finally, the variational theory is applied to solve the stress field and the normal pressure of the interface between pile and soil around the pile, and the ultimate frictional resistance on the interface of pile and soil is solved, thus the theoretical ultimate bearing capacity and the axial force of pile body are obtained. Combined with the actual measured data of the pile body axial force of the super-long cast-in-place pile, the rationality of the analytical method and the solution result is verified.
【作者单位】：莆田学院土木工程学院;河海大学水利水电学院;河海大学岩土工程科学研究所;
【基金】：省科技厅重点项目(2013H0040) 莆田市科技局项目(2014S05) 河海大学博士后基金资助项目(2016 411096)
【分类号】：TU473.14

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