超长水泥搅拌桩桩身强度的检测

本文论述在深厚软土地基上采用26m超长水泥搅拌桩加固5万m~3大型油罐地基，对工程桩桩体质量，用标准贵入试验和取芯室内无侧限抗压试验来检验。检测表明，淤泥质粘土中超长水泥搅拌桩桩体连续坚硬、10天龄期N63.5平均21．6击；150天龄期极体强度q_u平均2．5MPa。实践证明，该法是可行的，工程也取得了成功。文章对桩身标贯击数随时间和深度的变化与无侧限抗压强度的关系，以及无侧限抗压强度和E_50的相互关系进行了统计分析，建立了一些相关公式，可供类似的工程参考。

The in-situ strength inspection on deep mixing piles

This paper discussed the on - site inspection on 26m deep mixing piles used as the foundation of a 50 000m3 oil tank. For the quality of project piles, the in - situ inspection methods of the standard penetration test and unconfined compression test are proposed.The test results show that the pile shaft of deep mixing piles is continuous and hard, the SPT blow count N63.5 is 21. 6 at 10 day ages, and the unconfined compression strength quis 2. 5MPa at 150 day ages. The practice testifies that the method is feasible and the oil tank project is successfully built. The paper also gives the N63.5 change at differ-ent depth, the relation of N63.5 vs- qu, E50 vs. qu modules of deformation for reference of other project.