Stability Analysis Of Tailing Dam Based On DEM With PFC

With a large number of mineral resources exploited, the number of tailing ponds increases and their scale is enlarged. The instability of tailing dams will lead to greater harm. In order to study the microscopic failure mechanism of tailing dams, the dam stability of a tailing pond in Hunan province is studied based on DEM (discrete element method) with PFC (particle flow code), and the geotechnical laboratory test and numerical simulation are applied comprehensively.The main research works are as follows:(1) The engineering background of this tailing pond is introduced systematically. The tailings in the tailing pond are divided into three layers according to the result of particle size analysis test. The physical mechanical properties and parameters of different tailings are gained through the triaxial compression test.(2) The micro-parameters calibration of tailings particles. The relationship between particle microscopic and soil macroscopic parameters is founded by the virtual biaxial test with soil particle assembly. The microscopic parameters of tailings of the PFC model are chosen, which show the same mechanical characteristics with the actual tailings.(3) The stability of the model of tailings dam built by particle flow code is analyzed with strength reduction method. It shows that, compared to limit equilibrium method, the safety coefficient is larger, and the most dangerous slip surface is shallow and its span is smaller. The reason is that there is no direct relation between microscopic and macroscopic parameters. It will show the particle properties after bonds break.(4) The effect of water and earthquake on the dam stability. It shows that, the area of the dangerous slip surface is wider under the action of water. The higher the water level, the larger the span of surface dangerous slip surface. It becomes deeper under the earthquake. The results are similar to the limit equilibrium methods’. There are some difference because of the different mechanism of water and earthquake.