| Tailings dam break has become one of the major disasters in our country in recent years,so a reasonable and accurate assessment of the dam before dam break is one of the important means to solve the disaster of tailings dam break.In the process of tailings dam evaluation,many factors should be considered,including the structure of tailings dam,geological conditions,hydrogeology and surrounding environment.When evaluating the stability of tailings dam,it is necessary to analyze its stress,stress state and deformation characteristics.According to the actual situation of Luanchuan water dew ditch tailings dam,this paper can be evaluated by field investigation,data analysis,numerical simulation and other means.In the field survey,it is necessary to record and analyze the structure characteristics,soil characteristics,dam stress,seepage and other conditions of the tailings dam in detail.At the same time,it is also necessary to assess the surrounding environment,including the nearby topography,hydrogeological conditions and other factors.The main contents are as follows:(1)Combined with the indoor dynamic and static mechanical test,the conventional physical properties of the soil and the critical parameters of the failure of the same bored soil under the corresponding working conditions were determined respectively,and the parameter results obtained by comparison finally used the data under saturation and non-consolidation as the most unfavorable parameter combination,which provided the parameter basis for subsequent simulation(2)The head distribution under normal working conditions and seismic conditions is calculated by formula,and the natural head distribution cloud and the head distribution cloud under pressure of section 1-1 and 2-2 are simulated by Geo-studio software,and the tailings dam body model in seepage environment is established,and the infiltration line requirements of the dam body under different working conditions are analyzed and derived,and the results show that the stability of the tailings dam body under the action of the seepage field of the water dew trench meets the requirements of the specification.(3)Based on the Geo-studio software using the Bishop method,the water volume and rainfall of the flood process are calculated after the basin is zoned,and compared with the flood discharge capacity to evaluate the factors affecting stability such as flood peaks and heavy rainfall under flood conditions.At the same time,the weakest sliding surface in the 1-1 profile and 2-2 profile was simulated by presetting the normal working conditions,flood working conditions and seismic working conditions,and the safety factor calculated by the weakest sliding surface was compared with the lowest safety factor,and the results showed that the tailings reservoir could remain stable under flood action and earthquake action.(4)Based on the elevation point coordinates of the tailings dam body by Mat DEM software,the corresponding model box is set for gravity accumulation and layering and material training is carried out,and the mechanical action between tailings sand particles is set from the microscopic level,and after importing the formation material information,the cementation between the soft sliding surfaces is broken,and the sliding failure of the soft surface is simulated,and the simulation results are consistent with the simulation results of G-studio software,which further demonstrates that the stability of the tailings reservoir dam body meets the specification requirements.(5)Based on the theoretical calculation,the stability analysis of the whole dam body under the actual flood erosion is carried out,and the maximum impact force and flood discharge capacity of the dam body are deduced,and the results show that the stability of the dam body meets the stability specification requirements after the third phase of dam heightening. |
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