精细地形下的尾矿坝稳定性及溃坝模拟分析

目前在尾矿坝稳定性和溃坝模拟分析方面，对溃口位置及水砂的流动状态难以做出准确判断。将尾矿坝稳定性和溃坝模拟有机结合，采用FLAC3D计算正常水位、洪水位、漫顶水位三种工况下尾矿坝稳定性，并利用Rhino与Fluent建立尾矿库及下游精细地形，开展尾矿库溃坝水砂在不同时刻及不同地形下的流动状态研究分析。结果表明:（1）浸润线的埋深随尾矿库水位的升高而变小，由正常水位升高至洪水位时浸润线埋深下降5～8 m，漫顶水位时坝顶浸润线沿坡面向下运移约8 m；（2）库水位对剪切带及尾矿坝稳定性有显著影响，从正常水位到洪水位时，剪切带纵向上不断向坝体内部延伸，横向上不断向坝脚延伸，剪切应变率增大为5.78×10?5，尾矿坝稳定系数由1.80下降至1.32；（3）达到坝顶时剪切带急剧缩短，而剪切应变率进一步增大为3.32×10?4，尾矿坝稳定系数由1.32下降到1.18。溃坝水砂的流动状态受地形影响明显，在山谷中表现为范围减小、流速增大的汇聚流动，在平坦农田处表现为范围增大、流速减小的发散流动特点。

Combined simulation analysis of the tailings dam stability and dam break under fine terrain

At present, it is difficult to accurately judge the location of the break and the flow state of water and sand in the simulation analysis of the tailings dam stability and dam break. Combining the stability of tailings dam with dam break simulation, FLAC3D is used to calculate the stability of tailings dam under the normal water level, flood water level and overtopping water level. Rhino and Fluent are used to establish the tailings pond and downstream fine terrain, the flow state of water and sand in dam break of tailings pond at different times and under different terrain is studied and analyzed. The results show that the buried depth of the phreatic line decreases with the increasing water level of the tailings pond. When the normal water level rises to the flood level, the buried depth of the phreatic line decreases by 5～8 m. When the normal water level rises to the overtopping water level, the phreatic line of the dam crest moves down about 8 m along the slope. The reservoir water level has a significant impact on the stability of the shear zone and tailings dam. From the normal water level to the flood level, the shear zone extends longitudinally to the interior of the dam body and laterally to the dam toe, and the shear strain rate increases to 5.78×10?5, the stability coefficient of tailings dam decreases from 1.80 to 1.32. The shear zone shortens sharply when reaching the dam crest, and the shear strain rate further increases to 3.32×10?4, the stability coefficient of tailings dam decreases from 1.32 to 1.18. The flow state of dam break water and sand is obviously affected by the terrain, which is characterized by convergent flow with reduced range and increased velocity in the valley, and the divergent flow with the increased range and reduced velocity in the flat farmland.