TEST COMPARISON OF INFLUENCE OF PRESSURE GROUTING ON UPLIFT CAPACITY OF MICROPILES
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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。Abstract: Micropiles commonly 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.
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Key words:
- pressure grouting /
- micropile /
- uplift capacity /
- secondary grouting
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