Experimental Study On Solidification Of Sandy Soil Based On MICP-B Technology

With the rapid development of China's economy and the rapid expansion of the population,the per capita available area of the country is decreasing,so the demand for land is increasing.China has a vast territory and a complex geological and terrain.Therefore,it is necessary to improve and strengthen the traditional soil in order to increase the available land.The existing soil reinforcement technology is to improve the soil by adding chemical additives to the soil.MICP mineralization is a new type of green soil reinforcement technology,which has the characteristics of quick response,controllable process and environment friendly.The bus widely exists in the soil bacillus,produced by bacteria in the process of a large number of The new supersedes the old.urease hydrolysis of urea,generate a large amount of precipitation of calcium carbonate filling with soil particles,so as to enhance the integrity and strength of soil particles.The application of MICP technology in the reinforcement of the soil,when the particle size range of 0.35~0.74 mm is better,when the technology is applied to the small particle size sand,the curing effect is poor.The popularization and application of this technology in fine sand.On the other hand,MICP mineralization technology in sandy soil mineralization,although the mineralization of the sample after the unconfined compressive strength value is higher,but the failure form of specimens of brittle failure,limit the technology of large-scale promotion and use in practical engineering.In order to increase the range of MICP curing technology to solidify the sand,the samples of the fine sand after mineralization are of good integrity and uniformity.In this paper,improved test device is added with expansion of polymer materials,selection of different parameters of the geotextile and improve the bacterial concentration of these 4 different methods to improve,make the technology applied in mineralization of fine sandy soil can improve the unconfined compressive strength value of the sample.The results show that the unconfined compressive strength range of the fine sand is increased from 267kPa~345kPa to 716~939kPa.The bacterial concentration value of OD600=0.7 determined by experiments,the best method to improve the fine sand specimen strength values for the incorporation of 0.08% A polymer materials,the fine sand sample MICP mineralization after the unconfined compressive strength can reach 2594 k Pa.In order to increase the range of MICP curing technology to solidify the sand,the samples of the fine sand after mineralization are of good integrity and uniformity.In this paper,improved test device is added with expansion of polymer materials,selection of different parameters of the geotextile and improve the bacterial concentration of these 4 different methods to improve,make the technology applied in mineralization of fine sandy soil can improve the unconfined compressive strength value of the sample.The results show that the unconfined compressive strength range of the fine sand is increased from 267kPa~345kPa to 716 kPa ~939kPa.The bacterial concentration value of OD600=0.7 determined by experiments,the best method to improve the fine sand specimen strength values for the incorporation of 0.08% A polymer materials,the fine sand sample MICP mineralization after the unconfined compressive strength can reach 2594 kPa.On the basis of the original MICP mineralization technology,the viscosity of coarse sand soil was increased by adding the viscous polysaccharide material with MICP-B curing technology.The cohesive force of MICP was used to test the cohesive force of the coarse-grained soil samples,and the cohesive force of the coarse sand samples was 50.24 kPa to the 359.3kPa after the common reaction method of MICP-B curing technology.The maximum value of the viscosity value of the coarse soil samples after the first treatment of MICP-B curing technology was 255.9kPa.In this paper,through the improvement and optimization of the experimental conditions,it provides the theoretical and experimental basis for the application of MICP technology in the fine sand with smaller grain size.On the other hand,the MICP-B curing technology has improved the disadvantage of brittle failure of the coarse sand soil sample,which makes it have obvious deformation when it is damaged.