文档介绍：压力注浆对微型桩抗拔承载力影响的试验对比
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苏荣臻
郑卫锋
鲁先龙
( 中国电力科学研究院,北京
100055)
摘
要:微型桩一般采用投石注浆法成桩,因此压力注浆工艺对微型桩承载力具有很大的影响。结合现
场试验,对压力注浆工艺对微型桩抗拔承载力的影响展开研究。试验研究表明,采用一次注浆成桩和直接灌
注细石混凝土成桩的微型桩抗拔承载力相差不大,而采用二次注浆工艺可较大幅度提高微型桩的抗拔承载
力,适当增大二次注浆量有利于提高微型桩的抗拔承载力。对于采用二次注浆工艺的微型桩,其抗拔承载力
计算应考虑二次注浆的提升效应。
关键词:压力注浆;微型桩;抗拔承载力;二次注浆
PARISON OF INFLUENCE OF
PRESSURE GROUTING ON UPLIFT CAPACITY OF MICROPILES
Su Rongzhen
Zheng Weifeng
Lu Xianlong
( China Electric Power Research Institute,Beijing 100055,China)
Abstract :monly use pressure grouting method,which influences the uplift capacity of micropiles. In
this paper,field tests about influence of pressure grouting on uplift capacity of micropiles were reported. Study shows
that the uplift capacity of primary grouted micropiles is almost the same as the uplift capacity of concrete micropiles.
However the uplift capacity of secondary grouted micropiles is enhanced. Increasing the amount of the second-grouting
properly can help micropiles enhance the uplift capacity. Calculating the uplift capacity of secondary grouted
micropiles must consider the effect of the second-grouting.
Keywords :pressure grouting;micropile;uplift capacity;secondary grouting
0
前
言
1
试验概况
微型桩通常是指直径为 0. 10 ~ 0. 40 m 的小直
径钻孔桩,其施工一般采用投石注浆法进行成桩,即
采用成孔—投入碎石骨料—压力注浆的方法。国内
外微型桩主要用于基础托换、挡土结构、边坡支护等
试验地点位于浙江省宁波市北仑电厂三期工地
内。场地地质条件见表 1 所示。
本次试验总计施工了