钻孔灌注桩后注浆技术

Post-grouting Technique for Bored Piles

后注浆是改善泥浆护壁钻孔灌注桩桩底沉渣、桩侧泥皮固有缺陷的一项重要技术。介绍了灌注桩后注浆技术的施工工艺以及工艺参数确定,阐述了后注浆加固机理,归纳了注浆后土体物理力学性能研究、桩端后注浆灌注桩的理论基础和其承载力影响因素的有限元分析研究的主要进展,分析了后注浆灌注桩承载变形特性,概括了后注浆灌注桩单桩竖向极限承载力计算的主要方法,对今后灌注桩后注浆技术的研究与应用有一定的指导意义。

Post-grouting is an effective technique to overcome the defects of settlement of debris on the bottom and shaft side mud cakes when slurry is used in boring for bored piles. The construction technology for post grouting and the parameter selection are presented in the paper. The mechanism of strengthening of a bored pile by post-grouting is also introduced. Major developments in the study on the physical and mechanical properties of surrounding soil after post-grouting, theoretical foundation for post-grouted bored piles with grouting made to the pile tips and analyses by finite element method on the factors affecting the bearing capacity of post-grouted bored piles are summarized. The bearing capacity behavior and deformation properties of the piles are also analyzed. And finally major methods to calculate the vertical bearing capacity of the single post-grouted bored piles are summarized. It may provide some guidance for the research and application of post-grouting technique for bored piles in future.