后注浆提高钻孔灌注桩单桩承载力分析

钻孔灌注桩存在桩端沉渣和桩侧泥皮,使其承载力不能充分发挥。后注浆技术可以消除其固有缺陷,可以提高单桩承载力。后注浆对不同持力层的适应性和单桩承载力提高的幅度是不同的。通过对北京、上海、天津、武汉地区大量已有的后注浆工程实例的承载力提高幅度进行对比分析,考虑安全储备后,提出了承载力提高的大致范围,为钻孔灌注桩后注浆技术设计和施工提供了参考依据。

Summary and analysis of increasing range of bearing capability of single bored pile after grouting

There are bottom sediment and slurry skin at pile side in bored piles, so that the bearing capability of piles can not fully develop. Post-grouting technique can eliminate the above inherent defect and enhance the bearing capability. The adaptability of post-grouting and the increasing range of the bearing capability are different in different bearing strata. The increasing range of the bearing capability is summarized according to the numerous examples of construction projects in Beijing, Shanghai, Tianjin and Wuhan. After comparing and analyzing these data and considering the safe reserve, the general increasing range of the bearing capability has been put forward in the above four regions. The advised general increasing range can provide reference to design and construct bored pile after grouting.