钻芯检测超长桩的最大桩长计算与关键技术

顺应大跨径桥梁和高层建筑等结构物下超长桩研究的需要,在现有规范的基础上,给出了超长桩适宜钻芯的最大桩长计算公式,例举了如何制定实体超长桩钻芯的较高要求,分析了配套的钻探技术要点,介绍了桩长74.02 m的钻芯实例。结果表明,钻芯检测超长桩要求基桩施工期认真监测,详细记录;钻芯时应在执行现行规范的基础上,根据给出的公式确定严格的钻芯方案和参数;超长桩钻芯成败取决于基桩施工和钻芯两工序的质量。

Key technology and calculation of maximun length in super-long pile core-drilling test

Fitting in with the needs of studying the super-long pile under the long span cable-stayed bridge or high-rise building, based on the present codes, authors have given the calculating formulas of the maximal core-drilling length of super-long piles, illustrated how to make a practical technological process of core-drilling in super-long pile by example, analysed some keys of core-drilling in super-long pile, introduced one core-drilling engineering of super-lone pile with 74.02 m. The results of study show that controlling strictly and noting detailedly will be asked during making super-long pile, the scheme and parameter of core-drilling should be determined on the bases of present codes and these calculating formulas, and the quality of pile-constructing and core-drilling will lead to success or failure in the course of core-drilling in super-long-pile.