IMPACT OF STONE CONTENT TO SHEAR PROPERTIES OF SOIL-ROCK MIXTURE USING PARTICLE FLOW CODE SIMULATION

DEM numerical models based on PFC^2D contact bond model are performed to probe the impact of stone content variation to shear properties of soil-rock mixture(S-RM).The micro parameters of unbound granular materials are calibrated with lab large-scale direct shear tests. Then the shear properties of S-RM of different stone content under different normal stress are studied. The result shows that for S-RM under the same normal stress, the high stone content would result in the high peak shear stress, the high shear strain at peak shear stress, the high post-softening strength, the stronger dilatation behavior, the more shear "leap" behavior. The friction angle of the S-RM increases and the cohesion decreases with the increase of the stone content. The cohesion keeps almost constant after stone content exceeds 50%. For S-RM with the same stone content, the high normal stress would have the high peak shear stress and the stronger strain-softening behavior. The shearing process of S-RM mainly overcomes the friction energy and strain energy are overcome whilst the change of the kinetic energy is almost zero.