| Microbial Induced Calcium Carbonate Precipitation(MICP)is an emerging green and environmentally friendly improvement technology that has unparalleled advantages over traditional chemical methods,such as low energy consumption,green and sustainable development,which precipitates inorganic mineral crystals through microbial metabolic activity and is one of the current hotspots in soil improvement technology with minimal environmental impact.With further research,this technology is not only applicable to soil with large pores such as sand and silt,but also to lowpermeability cohesive soil.In western Jilin Province,there are issues of channel bank erosion and damage caused by dispersive soils.Therefore,the application of MICP in improving dispersive soils in the western region of Jilin Province is of significant importance for enhancing the ecological environmentThis study used Sporosarcina pasteurii as the experimental strain and cultured a suitable concentration and activity of microbial solution.The dispersed soil was treated by direct mixing,and dispersion tests and unconfined compressive strength tests were carried out on the soil improved by microbial treatment.The effects of p H value,concentration,and curing time of the bonding solution on the improvement effect and mechanical properties were investigated.The results showed that the technology could effectively reduce the dispersion of the soil,and the optimal improvement effect was achieved at p H 8,a concentration of 1.0 mol/L,and a curing time of 7 days.The strength of the soil improved by microbial treatment was increased,and the maximum strength increase was achieved at p H 8,a concentration of 1.0 mol/L,and a curing time of 7days.Finally,the relationship between the amount of calcium carbonate precipitation and the dispersion index and unconfined compressive strength was investigated.The effect and mechanism of MICP on improving the dispersion of soil were comprehensively analyzed from both macro and micro perspectives based on Scanning Electron Microscope experiment.It was found that the dispersion index and unconfined compressive strength were approximately negatively and positively correlated with the amount of calcium carbonate precipitation,respectively.MICP promotes the formation of calcium carbonate through microbial action and improves the soil’s resistance to dispersion and strength by changing p H values and replacing sodium ions.This study applied the MICP technique to dispersed soil with good results,expanding the application range of microbial mineralization technology and providing new ideas for the improvement of dispersed soil. |
