后注浆工艺在桩基施工中的应用

Application of Post-Grouting in Pile Foundation Construction

灌注桩后注浆是在混凝土灌注桩成桩后一定时间,利用预先装设于灌注桩底、桩侧的注浆导管和与之相连接的桩端、桩侧注浆阀进行高压注浆,通过渗入(粗颗粒土)、劈裂(细粒土)、填充(虚土)、压密(非饱和松散土)桩底沉渣和桩侧泥皮以及土层,固结桩端沉渣和桩侧泥皮以及一定范围内的土层,改善桩土工作界面,从而改善桩侧摩阻力和桩端承载力,进而提高单桩承载力,相应减少桩基沉降的一项桩基改进技术。

Post-grouting into bored cast-in-situ piles is performed through the grouting pipes previously installed at the bottom and the shaft of the cast-in-situ piles,and is pressurized by the grouting valves connected with it,to carry out high-pressure grouting at a certain time after the formation of the concrete cast-in-situ piles The post-grouting can act infiltration(coarse grain soil),splitting(fine grain soil),filling(loose soil),compaction(unsaturated loose soil)to the pile bottom sediment,pile shaft mud and soil layer at the bottom of the pile.It is a pile foundation improvement technology that strengthens the pile end sediment,pile side mud and soil layer in a certain range,improves the working interface of pile and soil,greatly improves the pile shaft friction resistance and pile end bearing capacity,thus greatly improves the ultimate bearing capacity of single pile and correspondingly reduces pile foundation settlement.