A systematic framework for the 3D finite-discrete modelling of binary mixtures considering irregular block shapes and cohesive block-matrix interfaces

A systematic three-dimensional finite-discrete approach that considers realistic irregular blocks and cohesive block-matrix interfaces is proposed to simulate a binary mixture of geomaterials. First, the photogrammetry-based technique is employed to acquire realistic irregular block shapes, which are subsequently represented by spherical harmonics (SH). Next, the realistic binary mixture models are reproduced by random allocation of the SH-based irregular blocks into the sample domain. The cohesive zone model is employed to capture traction-separation responses of the block-matrix interface and to simulate progressive failure of the binary mixture. A hybrid model for the finite-discrete simulation of binary mixtures is established by inserting cohesive elements into the mesh model of binary mixtures. A series of basic mechanical tests are performed to calibrate modelling parameters and validate reliability of the proposed method. The proposed model shows great potential for addressing heterogeneous binary mixtures of geomaterials that maintain the characteristics of both continuity and discontinuity.