微生物诱导碳酸钙沉积(MICP)技术对膨胀土性能改良研究

Research on Microbially Induced Calcium Carbonate Precipitation(MICP)Technology for Improving the Performance of Expansive Soils

通过试验分析不同养护时间下微生物诱导碳酸钙沉积技术改良土的膨胀特性,表明微生物对膨胀土进行固化改良后,其自由膨胀率在养护1、3、7、15、30 d后与重塑膨胀土样相比,分别减小了10.0%、13%、15.8%、20.4%、20.6%;微生物改良膨胀土的自由膨胀率随着养护时间的提高持续减弱,在养护前15 d内快速减小,15 d后趋于稳定;随着膨胀土自身膨胀特性的增强,微生物对其改良效果越显著;微生物固化作用能够明显削弱膨胀土的浸水膨胀率。

The expansion characteristics of soil improved by microbially induced calcium carbonate deposition under different curing time were analyzed.The results showed that the free expansion rate of soil improved by microbially cured expanded soil decreased by 10.0%,13%,15.8%,20.4%and 20.6%,respectively,after curing for 1,3,7,15 and 30 d,compared with the remodeled expanded soil sample.The free expansion rate of microbial modified expansive soil continued to weaken with the increase of curing time,rapidly decreased within 15 d before curing,and stabilized after 15 d.With the enhancement of swelling property of expansive soil,the improvement effect of microorganism is more obvious.The effect of microbial solidification can significantly reduce the water swelling rate of expansive soil.