Abstract:In this study, we conducted a direct shear test of undisturbed loess (typical low clay silt) in the Lanzhou new district, used high-power electron microscopy, and conducted an energy spectrum test to obtain the cohesion C, internal friction angle φ, mineral element ratio, and micro structural parameters of the loess. We then analyzed the correlation among the microcosmic parameters, the mineral element ratio, and the shear strength (C, φ) of the soil samples by a single-factor and multiple regression fitting method. The results indicate that the φ value has a linear correlation with the mean angle value, and the correlation coefficient of the fitting formula is 0.82. The cohesion C value is linearly correlated with the kurtosis and skewness of the long axis, Fe/Si, Al/Si, and K/Al, and the maximum correlation coefficient after fitting is 0.99. The fitting formula for the microcosmic parameters and shear strength provide a new research approach for predicting the shear strength of soil samples.