超长钻孔灌注桩桩端后压浆效果检测 - 岩土力学.pdfVIP

第27 卷第5 期 岩 土 力 学 Vol.27 No.5 2006 年5 月 Rock and Soil Mechanics May 2006 文章编号：1000－7598 －(2006) 05 －0849 －04 超长钻孔灌注桩桩端后压浆效果检测 戴国亮，龚维明，薛国亚，童小东 （东南大学 土木工程学院，南京 210096 ） 摘 要：主要介绍一根超长钻孔灌注桩桩端后压浆试验成果，包含自平衡静载试验以及钻孔取芯试验。结果表明，超长钻孔 灌注桩桩端后压浆水泥浆液上返高度在该类地质条件下约达15 m 左右，但水泥浆液在地下需要较长时间才能达到设计强度， 且分布不均。桩周土层标贯试验表明，贯入击数与压浆前相比，普遍提高。自平衡静载荷试验结果表明，压浆后承载力增加 50 % 。因此桩端后压浆对提高桩承载力和改善荷载传递性能有明显的效果。 关 键 词：超长桩；后压浆；承载力；自平衡法 中图分类号：TU 473 文献标识码：A Effect examination for a base post-grouted overlength drilling pile DAI Guo-liang, GONG Wei-ming, XUE Guo-ya, TONG Xiao-dong (College of Civil Engineering, Southeast University, Nanjing 210096, China) Abstract: This paper mainly introduces the test results of an overlength drilling pile with base post grouting technique, including self-balanced loading test and coring test. According to tests, the grouting cement can rise up to 15 m from pile tip under the geological and construction conditions, but requires much time to reach its design strength and distributes non-uniformly around pile tip. The standard penetration tests (SPT) show the number of SPT after grouting is more than that of before grouting. The self-balanced test results indicate that the bearing capacity of the test pile afte