Study On The Relationship Between Macroscopic Mechanical Properties And Microstructure Of Red Clay Polluted By Alkali

During the previous study on the bearing capacity of the red clay in the foundation of Guizhou Aluminium Plant,it was found that the red clay was seriously polluted and its physical and mechanical properties were different from those of the common red clay due to the infiltration of waste lye in alumina production.Therefore,the mechanical properties and microstructure of alkali-contaminated red clay are studied.In this paper,based on the actual contaminant concentration and the sources of the production process of Alumina,the time and concentration effect were taken into account,and the original red clay with alkali pollution was tested by indoor soil.Base on this,the aspect of the physical and mechanical properties,microstructure and macro-microscopic connection of alkali pollution red clay were studied.we put forward some suggestions on the macro-microscopic study of soil mass.The main points and conclusions include:(1)At low concentration,and the overall physical and mechanical properties become worse.In high concentration,the physical and mechanical properties of the whole are better.At the sources of the production process of Alumina,the physical and mechanical properties are the best.In the 0d-10 d,the physical mechanics property of the alkali contaminated soil gets better,the greater the quality score becomes better.The physical and mechanical properties of 10 d ~ 40 d have great fluctuation,and there is no obvious corresponding relationship between them.The physical and mechanical properties of 40 d ~ 80 d tend to be stable.(2)Microstructure: include the method of qualitative analysis,such as three-dimensional treatment,elemental analysis,pore equivalent elliptic long axis orientation distribution,and also include other quatitative analysis methods for the SEM images of the soil on the fracture surface,and the methods of extracting particle shape fractal dimension,particle size,total number of pores,the ratio of inert pore area,the number of inert pores,the probability distribution index of the pore area,the pore area,the pore probability and the number of particles,were obtained: under the low mass fraction,the microparameters in the whole were reduced,the particles in the soil and the pore morphology were less varied.Much as the connection between particles is weak in fracture.Under the high quality score,the microcosmic parameters are larger in the whole,and the granule and pore morphology in the soil vary greatly.Connection between particles is weak in the fracture,the friction between the soil particle also play a role.Under the sources of the production processof Alumina,the microcosmic parameters were reduced in the whole,and the soil particles and pore morphology changed the most.Friction between soil particles plays a major role.The response laws of microstructure to macroscopic physical and mechanical changes were analyzed from alkali-soil action,compression and shear(3)The relationship between macroscopic mechanics and microstructure: by regression analysis,the nonlinear regression equation of the anti-shear index and microstructure parameters of the red clay was obtained.The correlation between microstructure parameters and shear strength is analyzed by grey correlation theory.Based on the RES theory,the BP network model was established in Matlab platform,and the interaction between micro indexes was analyzed,and the weight of the influence of microstructure parameters on the shear strength index was obtained.