Based on the refined method for constructing DEM model based on the computed tomography scanning of irregularly shaped(IRS) particles, a random technique for constructing DEM model for IRS rock block is proposed, and 3D DEM models for soil-rock mixture(SRM) which conforms to the macroscopic statistical rule are established. In order to study the mechanical properties and deformation mechanism of SRM with various rock block proportions(RBP), DEM numerical simulations of large scale triaxial tests are conduct...