SHEAR STRENGTH CHARACTERISTICS OF SOIL IN THE SLIDING ZONE ON HIGHWAY SLOPE IN GUIZHOU PROVINCE

To explore the change rule of strength and normal deformation properties of soil in the sliding zone on highway slopes, taking the mountainous highway in Guizhou Province as an example, the paper studies the shear strength characteristics of sliding zone soil under different water content and normal stress by ring shear apparatus. The results show that there is a good linear relation between the peak strength and residual strength of sliding zone soil with different water content and the normal stress. The larger the normal stress is, the larger the shear displacement required for the specimen to reach the peak strength will be. Under the condition of high water content, the shear stress tends to increase when the sliding zone soil decreases from peak strength to residual strength. With the increase of water content, the cohesion shows an increasing trend, and the internal friction angle reaches the peak near the plastic limit and then gradually decreases. The study on the properties of sliding zone soil will provide scientific basis for the identification and prevention of highway landslides.