Abstract: A discrete element method contact model building method includes: selecting a filling body in a disaster-causing structure to obtain a change rule of cumulative loss of the filling body ; performing test simulation, and determining a relation function of each group of corresponding mesoscopic mechanical parameters in each time period and mesoscopic parameters of a DEM contact model representing a change rule of macroscopical parameters of the filling body; embedding each mesoscopic parameter relation function into an existing particle contact model, performing test simulation, and updating a fracture failure criterion of the contact model according to a corresponding relation of macro-mesoscopic strength during model failure; and based on a seepage failure indoor test, building a seepage failure discrete element calculation model, and simulating the seepage failure process of a rock and soil mass by using the obtained particle contact model and the fracture criterion of the particle contact model.

Abstract: A rock mass engineering cross-scale simulation calculation method based on REV all-region coverage, including establishing a rock mass engineering scale calculation model of particles and joints, and providing the model with particle material parameters and contact parameters; performing model region division dividing the model into multiple finite elements, and performing all-region coverage and mesh division using the finite elements, wherein a volume of the finite element is equal to a representative elementary volume of a REV model; and applying boundary conditions, calculating force and motion information of finite element nodes using a continuous medium method, obtaining a failed finite element according to the node force and motion information, and calculating motion information of particles of the REV model in the failed finite element using a discontinuous medium method. According to the calculation method, the calculation efficiency is improved, and the accuracy of calculation results is ensured.