灌注桩后注浆技术应用及施工方法

Application and Construction Method of Post-Grouting Technology

灌注桩在成桩后一定时间内,由预设于桩身内的注浆导管及与之相连的桩端、桩侧注浆阀通过高压注浆泵注入一定压力的水泥浆,通过浆液对桩端沉渣和桩端持力层及桩周泥皮起到渗透、填充、压密、劈裂、固结等作用来增强桩端土和桩侧土的强度,从而达到提高单桩承载力,减少沉降量的一项技术措施。传统灌注桩由于在成孔过程中造成桩底和桩侧土的破坏,土体承载力显著降低,成桩后桩体由于土体承载力的降低而产生下沉。采用后注浆技术后,桩的承载力和沉降量大幅提高,单桩承载力可提高30%-150%,经济效益显著。

in a certain period of time after the pile is formed,the grouting pipe preset in the pile body,the pile end and the pile side grouting valve are injected with a certain pressure cement slurry through the high pressure grouting pump,and the strength of the pile end soil and the pile side soil is enhanced by the effect of slurry on the pile end sediment and the pile end bearing layer and the pile surrounding mud skin,so as to increase the bearing capacity of the single pile and reduce the settlement.Due to the failure of pile bottom and pile side soil,the bearing capacity of the traditional cast-in-place pile is significantly reduced,and the pile body after pile formation is sinking due to the decrease of soil bearing capacity.After adopting the post-grouting technology,the bearing capacity and settlement of the pile are greatly increased,and the bearing capacity of single pile can be increased by 30%to 150%,and the economic benefit is remarkable.