灌注桩后注浆技术应用研究及承载力影响分析

Post grouting technology and its influence on the bearing capacity of bored piles

对后注浆技术未能大幅提高灌注桩单桩承载力的工程个案展开分析研判,得出注浆过程控制不力是导致单桩承载力不足的主要原因。严格注浆管、射浆管、逆止阀制作质量管控与安装及注浆过程控制是能否成功注浆进而提高承载力的关键因素。工程案例中对承载力欠缺的区域进行了补桩处理,补桩时规范注浆装置制作、加强注浆过程管控,在补桩达到龄期后进行了静载试验,结果表明其单桩竖向极限承载力满足设计要求。

This paper studies a field case where post grouting technology failed to greatly improve the bearing capacity of the single pile,and concludes that the main cause for the insufficient bearing capacity of the single pile is the poor control of the grouting process.Strict quality control and installation of the grouting pipe,jet grouting pipe and check valve as well as the grouting process control are the key factors for successful grouting,hence improvement of the bearing capacity.In the above field case,the area with insufficient bearing capacity was treated by supplementary piles.During construction of the supplementary piles,the production of the grouting device was standardized and the control of the grouting process was strengthened.After the supplementary piles reached the aging period,the static load test was carried out,and the results showed that the bearing capacity of the supplementary piles met the design requirements.