钻孔灌注桩桩端后注浆技术及应用

PILE TOE GROUTING TECHNOLOGY FOR BORED PILE AND ITS APPLICATION

通过Φ700mm和Φ600mm两种桩径的各3组桩端后注浆和未注浆钻孔灌注桩的对比试验,对比分析桩端后注浆工艺对钻孔灌注桩的承载性能和施工耗时的影响。结果表明采用桩端后注浆工艺,可有效清除桩端沉渣、桩侧泥皮对于承载力的不利作用,改善桩的承载性状,大幅提高单桩承载力。同一承载力要求下,采用桩端后注浆工艺,Φ700mm灌注桩的有效桩长可以减短7～8m,Φ600mm灌注桩的有效桩长可以减短4～5m。Φ700mm的46m灌注桩可缩短为39m,每根桩成孔施工可节约6.2h,节约时间比例32.8%。

Through the comparison test of three sets of pile toe grouting and un-grouted bored piles of Φ700 and Φ600, it was compared and analyzed that pile toe grouting technology influence the bearing capacity and construction time of bored piles. The results show that the pile toe grouting process can effectively remove the adverse effects of pile toe sediment and pile-side mud on bearing capacity, greatly improve the bearing capacity of piles, and greatly improve the bearing capacity of single pile. With the same bearing capacity requirement, the pile toe grouting can reduce the effective pile length of Φ700mm bored pile by 7~8m, and the effective pile length of Φ600mm cast-in-place pile can be shortened by 4~5m. Moreover, the Φ700mm bored pile with a length of 46m can be shortened to 39m, and the construction time of each pile can save 6.2h, which save 32.8% of the time.