Influence of Coarse Grain Content on the Mechanical Properties of Red Sandstone Soil

Coarse-grained red sandstone soil is often used as embankment filling material but prone to being broken by extrusion, which lowers the stability of roadbed. This paper aimed clarify influence variation in coarse-grain content on mechanical properties coarse-grained soil. Soil with a grain size greater than 5 mm regarded soil, and soils different contents coarse grains were prepared cylindrical specimens diameter 300 height 600 mm. Under three confining pressures, large-scale triaxial apparatus was carry out shear tests. The results showed that (denoted p) increased, deviation stress static failure showing hyperbolic relationship. internal friction angle also increased hyperbolically, while cohesion reached peak value then decreased, maximum 133.8 kPa at p = 30%. As dilatancy increased. amount shrinkage when A equal 30% optimum material.