Multi-scale Finite Element Method for Simulating the Deformation Characteristics of Soil-rock Mixture Slope

Soil-rock mixture is a natural multi-phase geological material integrated by multi-grain mineral particles,and has significant heterogeneous and discontinuous mechanical properties.Based on the idea of soil cell element model,an elastic-plastic constitutive relation of soil-rock mixture considering the rotational degree of freedom of rock block is derived,and a multi-scale and hierarchical finite element program of soil-rock mixture is developed.Relevant model parameters are determined by large-scale direct shear tests on soil-rock mixture.Moreover,the proposed multiscale finite element method (FEM) is used to analyze the cross-scale formation and evolution of the shear band of soil-rock mixture slope.The results show that the multi-scale coupled FEM can scientifically simulate and predict the cross-scale evolution of the deformation of soil-rock mixture slope,and can effectively overcome the pathological mesh-dependency of conventional elastic-plastic FEM;during the deformation of soil-rock mixture slope,the rotational displacement of rock blocks mainly concentrates in the shear band of the slope,the maximum calculation result is 40.7°,and the rotational displacement of rock blocks outside the shear band is zero.