Research Of Weak Soft Soil Microstructure Characteristics Of Xingheng Highway

For Xing Heng highway which goes through the ancient lakes wetland areas, along thehighway the weak soft soil is widely distributed, this region is affected by natural factorssuch as rainfall and climate, which has the characteirstics distinct from the eastern coastalplains of soft soil.The massive researches and practices have proved that the project natureof soil has close relation to its mateiral ingredient and pellet distribution. Its microscopicstructure factor like grain shape, the distribution, arrangement and the way of link，the gapcirterion and the factor of porosity also determine the project nature of soil oil. Thecomplexity and randomness of soft soil’s microstructure lead to the complexity andrandomness of its macroscopic mechanical properites. In this article，through experiment,scanning electron microscope and fractal theory was used to study the microscopicstructure of soil mass under different stress state. The main research contents and results areas follows:￠1) Undisturbed soil by XingHeng highway along the weak soil indoor geotechnicalexperiment and X-ray diffraction (XRD)，draw XingHeng high-speed the basic physicaland mechanical properites of soft soil and mineral composition. Using scanning electronmicroscope (SEM) test technology for XingHeng high-speed inner soft soil under differentstress path along the horizontal section and vertical section of undisturbed soil samplemicrostructure characteristics were observed and analyzed different stress affectingmicrostructure characteristics of the sample.￠2) The soil microstructure parameter extraction and quantitative analysis. Use soilmicrostructure image data to extract the expression characteristics of soil microstructureparameters, such as patricle equivalent grain size, quantity, roundness, the stress state ofsoils with different horizontal section and vertical section of microstructure parameters,reveals the soft soil under different stress state their microstructure parameters changingwith the pressure, thus in this paper，the microscopic mechanism of macroscopicdeformation of soil.￠3) According to fractal theory which is suitable for the study of complex irregulargraphics features, this paper use the fractal theory depth analysis the microstructure of soil.At the same time, according to the characteristics of the study content, deifnes the researchof soil pore and grain distribution in the surface fractal dimension. Using the MATLABlanguage, has carried on the plane to soil microstructure image fractal dimensioncalculation, analysis of the test under different stress state after the fractal characteristics ofsoil microstructure.