Study Of Lattice Cellular Automation Of Numerical Simulation Of Rock Failure

With the development of mining engineering in deep underground and underground structure engineering, more and more mining tunnels and permanent underground caves will be built. On the other hand, some engineering disasters such as rockburst, landslide and so on occur from time to time. The study on mechanisms of rock failure is the basis to solve, finally to control these disasters. It demands of us to understand the mechanisms of rock failure from macroscopic to microscopic scale. Though many scholars have adopted various theories and methods to deeply study the rock failure, because of the complexity of this problem how to connect the macroscopic deformation and failure of rock with the evolution of cracks and defects in rock is still an issue that needs to be solved.In order to solve this issue, based on the elastic-plastic failure theory lattice cellular automata are presented to simulate the rock failure and study the mechanisms of rock failure and crack propagation, coalescence. Lattice cellular automata have the advantages of both cellular automata and lattice model. My work can be concluded as below,1. Verify the feasibility to adopt cellular automata to solid mechanics analysis. And based on the equilibrium equations, geometrical equations and constitutive equations cellular automata that may be used to solve 2-D truss elastic problems, 2-D truss plastic problems, 2-D rigid framework elastic problems and 2-D continuum elastic problems are introduced or presented.2. Lattice cellular automata are presented to simulate rock failure. And the basic thoughts to simulate rock failure, the methods to express the heterogeneity of rock and AE during rock failure are introduced in detail.3. Lattice cellular automata are used to simulate the fracture process of rock samples in uniaxial direct tension. And the influences of heterogeneity, slenderness and size of rock samples on rock failure in direct tension are studied. The model is also used to simulate the fracture process under indirect tensile conditions such as splitting and three-point bend and so on. The simulated results are in good accordance with the experimental results.4. Lattice cellular automata are used to simulate the failure process under uniaxial compression conditions. The influences of heterogeneity of rock, slenderness and size of rock samples on failure process of rock samples are studied.5. The crack extension is also studied based on lattice cellular automata. Firstly the extension of I-type cracks is simulated. The influences of the length of cracks and heterogeneity are studied in uniaxial direct tension. Then in uniaxial compression the fracture processes of samples with one or two pre-existing cracks are simulated. And the influences of geometries and distance of two pre-existing cracks on interaction mechanisms of two pre-existing cracks are studied.