| There are more than12000tailings dams in our country. The safety and stability of tailings dam has become the most important factors affecting mine production operation, the safety of the downstream people’s life and property and the surrounding ecological environment. Seepage failure is the key factor that causes the unstability of the tailings dam. But related theoretical basis for deepening the research at present, especially in the process of the seepage caused by dam siltation problem is extremely scarce. As a result, the scientific problems to carry out a detailed and quantitative research have important theoretical and practical value.On the basis of muddy water seepage sand column test, this paper studies the relationship of Tailings dam parameters such as permeability coefficient and tail ore porosity with the change of infiltration time. Based on experiment and the siltation mechanism’s result, the mathematic model of tailings dam considering muddy water seepage is established. Finally, combining with the engineering practice, through the numerical simulation of tailings dam stability calculation and analysis, the siltation mechanism is revealed. Paper’s main research content is as follows:(1)The muddy water seepage sand column test. This experiment chooses Beijing Yun Ye mining Bai Zao Yu tailings dam’s natural tail ore tailings as experimental material. By the research of the sand column, the rule of variation of physical parameters such as the coefficient of permeability and porosity of sand column reveals the internal mechanism of the tailings dam siltation, exploring the time and space distribution characteristics of siltation evolution.(2)The key problem influencing tailings dam seepage is the interaction problem between the deposition of tiny granules in the ore and muddy water seepage. The complex process in tailings dam seepage, accompanied by pore jams, dam body settlement consolidation, sedimentation consolidation of solid particles, and many other factors, needs to establish a reasonable and effective calculation model. This study, based on darcy’s law and the law of conservation of mass, establishes the muddy water siltation mathematical expressions expressed by permeability coefficient and porosity, gives actual boundary condition of the tailings dam according with the real situation and a brief overview of the related numerical methods.(3) In-depth study of law of seepage contributes to analyze the cause of the accident of tailings dam and its destruction form, to provide theoretical support for the related countermeasures. Based on the Beijing Yun Ye tailings mining Feng Jia Yu iron mine Bai Zao Yu tailings dam as the research object, taking the permeability coefficient of the material itself as the initial parameters and considering the laboratory test of the muddy water siltation variation law of permeability coefficient for tailings dam seepage with finite element method analysis, the influence law of the effect of muddy water siltation on tailings dam stability is researched by the numbers, in which, the seepage change law of parameters such as pore water pressure, displacement of dam body is calculated while the tailings dam working under different working conditions, velocity, seepage filed, seepage flow, seepage gradient, as to provide theoretical basis for the safety of the tailings dam stability evaluation.(4)The property of tailings is very complex under ever-changing environment and working conditions. In this paper, aiming at the shortcomings of the existing evaluation methods, based on detailed evaluation theory in slope stability evaluation, combining with the characteristics of tailings dam, basal and dam construction, a detailed evaluation method of tailing dam was established. According to relevant laws and regulations, technical standards and regulations, the stability of the present situation of Bai Zao Yu tailings dam and after heightening is calculated, which shows that the evaluation results is feasible and reliable. |
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