This paper aims to solve the negative effects of the large unfrozen water content and high compression of high warm and frozen soil on the stability of roadbed. In this study

by taking the silty clay in the permafrost regions of Qinghai-Tibet Plateau as the research object

15% ordinary Portland cement

high-performance Sulphoaluminate cement

and (ordinary Portland cement+high-performance Sulphoaluminate cement) were prepared as samples at negative temperature. The oven drying method

TDR (time domain reflectometry) technique

X-ray diffraction

scanning electron microscopy (SEM)

and thawing compression test were adopted to analyze changes of the total water content

changes of unfrozen water content

and the phase composition of the soil with the addition of soil stabilizers

as well as to compare the solidification effects of different soil stabilizers. MATLAB was used to develop CURVEEXTRACT image analysis system to deal with SEM image

which was then imported to the Image-ProPlus6.0 (IPP) software to analyze the characteristics of micro pore distribution

morphology

and directivity of high warm and frozen soil before and after solidification. The relationship between macroscopical and microcosmic before and after solidification was established based on the relationship between compression property and pore orientation fractal dimension. Results show that adding soil stabilizer could reduce the total water content and increase the unfrozen water content in the soil samples. After solidification

soil particles became closer

the pore area of the soil decreased

and the pore transformed from narrow to equiaxial. There was a good linear relationship between the pore directional fractal dimension (Df) and the coefficient of thaw compression (av). The better the curing effect was

the smaller the Df was

and the smaller the corresponding av was.