Static Stability Analysis of Tailings Dam Based on Finite Element Method

为了确保尾矿库的安全性，对尾矿库坝体要进行地震动力稳定计算，而在此之前要先对坝体进行静力分析。静力分析是动力反应分析的基础，其目的是确定震前坝体与坝基的应力状态，判断深层稳定性并为地震动力反应分析和液化分析提供基础。在进行尾矿坝初始应力状态计算时，采用邓肯 E-ν 模型计算尾矿静力状态下的应力应变，特别是剪应力状态。选取尾矿库原设计终期、扩容终期主坝模型和扩容终期副坝模型进行有限元静力计算分析，得出结论：尾矿坝在各个计算标高内，其有效大主应力、有效小主应力的分布及大小均在正常范围内，全部为压应力，坝体不存在拉应力区；尾矿坝的位移变形主要表现在垂直方向，总体上属一个漫长变形沉降过程；坝内最大剪切应力主要分布在初期坝底及库底基岩层；库内尾砂区域绝大部分剪应力值较小，不会产生相对错动滑移。最终认定，尾矿库静力状态下不存在深部滑动及较大变形区域，坝体是静力稳定的。In order to ensure the safety of the dam body of the tailings reservoir, the seismic dynamic stability of the dam body of the tailings reservoir should be calculated. Before this, the static analysis of the dam body should be carried out. Static analysis is the basis of dynamic response analysis, which aims at determining the stress state of the Dam Body and Dam Foundation before an earthquake, judging the deep stability and providing the basis for seismic dynamic response analysis and liquefaction analysis. When calculating the initial stress state of the tailings dam, the Duncan E-ν model is used to calculate the stress and strain, especially the shear stress state under the static state of the tailings dam. The main dam model at the end of design and expansion and the auxiliary dam model at the end of expansion are selected for the finite element static analysis, the distribution and magnitude of the effective major principal stress and effective minor principal stress are all in the normal range, all of them are compressive stress, and there is no tensile stress zone in the dam body. Displacement of the tailings dam occurs primarily in the vertical direction and, overall, constitutes a long-term settlement process. The maximum shear stress in the dam is mainly distributed at the initial dam bottom and the foundation rock of the reservoir bottom. Finally, it is concluded that there is no deep sliding and large deformation area in the static state of the tailing reservoir, and the dam body is statically stable.