旋喷桩加固泥炭质软土应用研究

Application of jet grouting in improvement of soft peat soil

文章总结了某港口工程泥炭质淤泥地层首次旋喷桩试验性施工失败的原因,基于泥炭质淤泥地基的特点,针对性地采取了降低浆液压力、采用复喷工艺、降低浆液水灰比、浆液中外掺石膏、由桩机档位控制注浆管的提速等改进措施。试验性施工及后续大面积施工的钻孔取芯检测,证明上述改进措施成功解决了泥炭质淤泥地基旋喷桩成桩难题,可为类似有机质地基的旋喷桩软基加固提供借鉴及参考。

The cause of failure of the first trial construction of jet grouted piles in peat mud in a port project is summarized in the paper,and based on the characteristics of the peat mud,the following improvement measures were adopted,such as decreasing the slurry pressure,adopting the re-jetting process,reducing the water-cement ratio,adding gypsum in slurry;and controlling the withdrawing speed of jet grouting by rig gear.The results of testing on the core samples from the in-situ trial and the subsequent large-scale construction showed that the above-mentioned improvement measures had successfully solved the problem of unsatisfactory quality of jet grouted piles in peat mud,which can provide reference for similar ground improvement projects by jet grouting method in organic soils.