基于耦合模型的尾矿坝稳定性对比分析

以山西襄汾尾矿坝2008年溃坝案例为研究背景，分别采用应力-渗流耦合和连续-离散耦合数值分析方法建立数值模型。应力-渗流模型根据坝顶实际水位和溃坝出水点设定水力水头差，连续、离散网格区域分别采用有限差分FLAC和颗粒离散元PFC进行建模。在应力-渗流耦合计算的浸润线基础上，采用连续-离散耦合计算分析坝体在静水作用下的失稳破坏特征，同时以应力-渗流耦合的计算结果来验证连续-离散耦合研究的有效性，使边坡稳定性分析方法获得了新的应用。结果表明：①应力-渗流耦合的边坡稳定性分析结果与连续-离散耦合方法呈现出的位移发展趋势基本一致，并可获得后者计算所需的浸润线特征；②引入浮重度参数，将坝体材料考虑为在静水作用下的含水土体，可用于连续-离散耦合算法，其模型计算结果与溃坝成因基本一致。

Comparative Analysis of Tailings Dam Stability Based on Coupling Model

On the background of Xiangfen tailings dam-break of Shanxi province in 2008，the numerical model is built by using stress-seepage coupling and continuum-discrete coupling numerical analysis method.According to the actual dam water level and the point of dam-break，the stress and seepage model sets hydraulic head.Continuum and discrete area are analyzed by finite difference grid FLAC and discrete element PFC，separately.Based on the seepage line calculated by the stress-seepage coupling，the instability and failure characteristics in hydrostatic action are analyzed by the continuum-discrete coupling.Simultaneously，the effectiveness of continuum-discrete coupling is verified by the calculated results of stress-seepage coupling model.Therefore，the slope stability analysis method gets new application.The results show that ①Displacement development of slope in the stress-seepage coupling and continuum-discrete coupling maintains superior consistency in the process of computation，and thus，the seepage line required by the continuum-discrete coupling can be obtained.②Using the buoyant weight parameters，dam materials are considered as soil mass containing water under hydrostatic pressure，which can be used in continuum-discrete coupling method.The calculation results of model are basically the same as the reason of dam-break.