Stability Analysis Of A Tailing Reservoir Dam Under Valley Topography

With the continuous expansion of mine production capacity,most of the built tailings reservoirs can not meet the mine's emission needs.However,as far as the reality is concerned,there are not many topographic conditions near the mining area that can meet the new tailings reservoir.According to the actual topographic conditions of a mine,it is planned to build a new tailings reservoir downstream of the built tailings reservoir to stack tailings.It is planned to build another dump next to the downstream of the new tailings reservoir,and the waste rock of the dump is planned to be used as raw material for the new tailings dam body.After the completion of the construction work,the upstream tailings reservoir,the new tailings reservoir and the new dump will be integrated.Whether the risk of tailings reservoir can be controlled,whether the tailings reservoir can operate safely and steadily,whether the adjacent stacking of the dump and the tailings reservoir dam body is beneficial or harmful to the stability of the dam body,the corresponding research carried out in this paper is mainly as follows:1)Select tailings from reservoir area for screening test,seepage test and triaxial shear test.Through relevant experiments,qualitative and quantitative research and summary are made on the properties of tailings.The size composition,deposition law,permeability and shear resistance of tailings are studied and analyzed,and the basic mechanical parameters of tailings are obtained.2)The research stage is divided into three stages: the early stage,the middle stage and the late stage of the new tailings reservoir.The seepage field distribution characteristics and dam stability of the new tailings reservoir dam under different working conditions in three stages are analyzed by using Geostudio software.Through analysis,it can be concluded that the dump site adjacent to the tailings dam body can not only add a surcharge to the dam body,but also prolong the seepage path,reduce the saturation line,prevent piping and other risks,which is conducive to the stability of the dam body.3)The stability of new tailings reservoir dam with different service periods is analyzed and studied by Midas software in three-dimensional state.It can be seen that with the construction of new tailings reservoir,the areas where deformation and destruction occur mainly concentrate on the empty face of the dump and the empty face of the dam body.The dump effectively alleviates the large displacement and stress concentration at the dam body of the tailings reservoir,and is conducive to the stability of the dam body of the tailings reservoir.4)The relevant parameters of upstream tailings dam break are calculated theoretically,and the evolution path and height along the upstream tailings dam break are obtained.The Midas software is used to reconstruct the model and analyze the stability of the new tailings reservoir under the condition of dam break.It can be seen that dam break in upstream tailings reservoir will not lead to overtopping risk,and the deformation area is basically the same as that before dam break,which will not affect the stability of the dam body.