粉喷搅拌桩桩机自引孔技术的研究及应用

Research and Application of Self Drilling Technology for PowderJet Mixing Pile Machine

为解决粉喷搅拌桩施工中管内粉体难以喷出容易造成输粉管爆管、堵管等故障,依托具体工程,经现场试桩得出不同密度土层对应的电流负荷,确定土层需要先进行自引孔及引孔次数,减少土体密度以降低被动土压力。结果表明:与常规施工方法相比,在正式喷粉成桩前利用桩机自身的钻头对土体进行搅松引孔,使输粉管压力差达到成桩要求,喷粉顺畅,保证了成桩质量。相比采用冲孔桩机引孔回填黏土的引孔方式,粉喷搅拌桩桩机自引孔技术具有引孔速度快、施工简单、孔内无需回填黏土、经济环保等优势,是一种在含有机杂质或局部突变的高密度土层处理中简便易行的施工方法。

In order to solve the problem of difficulty in spraying powder from the pipe during the construction of the powder spraying mixing pile machine,which can easily cause faults such as explosion and blockage of the powder conveying pipe,based on specific engineering projects,the corresponding current loads of different density soil layers were obtained through on-site pile testing.It was determined that the soil layer needs to undergo self drilling and drilling times first to reduce soil density and reduce passive soil pressure.The results show that compared with conventional construction methods,before the formal powder spraying pile is formed,the drill bit of the pile machine itself is used to loosen and guide the soil,so that the pressure difference of the powder conveying pipe meets the requirements of pile formation,and the powder spraying is smooth,ensuring the quality of pile formation.Compared to the method of using a punching pile machine to guide holes and backfill clay,the self drilling technology of powder jet mixing pile machine has advantages such as fast drilling speed,simple construction,no need to backfill clay in the hole,and economic and environmental protection.It is a simple and feasible construction method in high-density soil layer treatment containing organic impurities or local mutations.