Experimental Study On Shear Strength Of The Complex Of Plant Roots And Mineralized Aeolian Sand By Microorganisms

Microbial induced mineralization technology is a new environment-friendly technology that has little impact on the natural environment and can maintain the balance of the original environment.The mineralized bacteria themselves are formed between the sand particles due to the biochemical reaction and filled with gelatinous calcium carbonate,which increases the adhesion between the sand particles and increases the strength and rigidity of the sand body.Therefore,this technology is widely used Apply to soil reinforcement and improvement.In this paper,the application of sand-solidified sand-solidified soil in the desert for sand control and sand-fixing is an engineering background.Through a series of experiments,aeolian sand mulching and plant roots are combined to carry out sand-fixing protection.In order to apply the MICP technology and plant sand fixation technology to the wind and sand fixation work in the desert,it is necessary to find out the sand plant species,the suitable concentration of the mineralized bacteria and the calcium source cement that can be adapted to the induced mineralizing bacteria applied by the MICP technology Liquid concentration.And study whether it is possible to establish the three components of urea,calcium chloride and mineralized bacteria to form a new type of film-curing basic material,and finally established.Studies have shown that under different urea,calcium chloride and bacterial liquid dosages,the growth of the three sand plants is not the same.The overall germination rate of Artemisia sphaerocephala was higher than that of Sami and Satawang after 10 days of each dosage?on the 7th day with water addition?.The germination rate of Artemisia sphaerocephala was as high as Urea 6g/L and Ca CL₂ at4g/L.Germination rate up to 54%.Finally,by quantitatively comparing the germination rates of Shami,Shatwang,and Artemisia sphaerocephala,and qualitatively comparing the mineralization effect of the sand surface layer,finally,Artemisia sphaerocephala was selected based on comprehensive consideration of these two aspects.Taking Artemisia sphaerocephala as a sand control and sand fixation plant,ammonium chloride and artemisinin gum were added to the new material for sand fixation and sand control to carry out a four-factor three-level plant cultivation orthogonal test.germination rate.Based on the range analysis of the orthogonal test,a further study was conducted to obtain a sand-fixing and sand-control method under the orthogonal experiment of Artemisia sphaerocephala that could not only fix the surface aeolian sand soil,but also improve and stabilize its germination rate,increase the water-holding capacity and nutrients of the aeolian sand The optimal mix ratio of new-type coating materials is required.The optimal mixing ratio is Bacillus bacilli OD value is 0.45,urea:calcium chloride:ammonium chloride:artemisinin gum=4:6:0.5:1.Finally,the effects of different reinforcement lengths,different quality reinforcement ratios,and different mineralizing bacteria concentrations on the shear strength characteristics of Artemisia sphaerocephala root reinforced aeolian sand combination solidified by MICP technology were studied.The results of the study indicate that the optimal dosage of Artemisia sphaerocephala root is 0.6%and the optimal OD value is 0.9 under the optimal reinforcement length of 15mm.Optimum length of 15mm reinforced mineralized bacteria OD value 0.9solidification rate of 0.6%of the test piece,when the confining pressure 300k Pa,the residual stress exhibited the most ideal?the final value strength effect is good and economic?in the future on-site test should focus on the mixing index.The optimal reinforcement length of Artemisia sphaerocephala root was 15mm.At each reinforcement rate,the mineralized bacteria had an OD value of 0.5.The cured samples showed pull-out damage.When 0.9 continues to increase to 1.3,the pull-out and pull-out coexistence type destruction.It was found that the exertion of the tensile strength of the reinforcement material is positively related to the curing effect of aeolian sand:Under the same conditions,the maximum stress value of the solidified reinforced aeolian sand under the concentration of mineralized bacteria at an OD value of 0.7 is about 3.3 times that under the condition of OD value of 0.5;Under the same conditions,when the bacterial concentration OD value is increased from 0.5 to 0.7,the maximum partial stress of solidified reinforced aeolian sand increases by a large amount.At this time,the maximum partial stress increase is about 1.5 times that of unreinforced solidified aeolian sand.