桩侧桩端后注浆技术在冲孔灌注桩的应用实测研究  

Applied Measurement Research of Punching Pile with Pile Profile and Pile Bottom Grouting Technique

作　　者：万征[1] 

机构地区：[1]中国建筑科学研究院地基基础研究所,北京100013

出　　处：《建筑科学》2014年第5期67-72,共6页Building Science

基　　金："十二五"国家科技支撑计划项目(2012BAJ07B01)

摘　　要：通过分析都江堰地区冲孔灌注桩试桩试验结果,对桩侧、桩端后注浆技术在冲孔灌注桩中的实际应用进行研究。采用自平衡方法对单桩进行加载试验,得到桩身侧摩阻力分布以及桩底反力发展过程。用理论公式与实测反力进行比较,分析自平衡方法测试的特征。理论公式计算与单桩静载试验结果对比表明:①理论公式中桩侧承载力计算结果偏大,对比实测后注浆桩侧侧摩阻力,注浆桩侧阻力增强系数增强后的桩侧摩阻力值偏高;②桩端后注浆采用桩端增强系数修正后的桩端阻力与实测结果基本相符合;③单桩静载试验结果的Q-s归一曲线可采用双折线来近似表达,给出单桩静载的预估曲线公式。预估结果表明与实测具有较好的一致性。The research about practical application of grouting technique with pile side,bottom for bored pile is developed through the analysis of bored pile in Dujiangyan region of test results. The loading tests with self-balance method on single pile are carried out. The development process of distribution for pile side friction and pile bottom counterforce are obtained. The calculated results based on theoretical formula are compared with the test results. Characteristics of self-balanced method tests are analyzed. Comparison between theoretical calculation and static load test results shows that：（ 1） Value of bearing capacity calculated of pile side is larger than that of test results, and value of pile side friction revised by enhanced coefficient of grouting pile is large;（ 2） Value of post-grouting pile bottom resistance enhanced is basically consistent with the measured results;（ 3） Curve of normalized Q-s static load test results can be expressed with double line approximated,and prediction of curve formula for single pile static load test is derived. A good agreement between prediction and test results is showed.

关 键 词：灌注桩 后注浆 侧摩阻力 静载试验 

分 类 号：TU473.14[建筑科学—结构工程]