Analysis On Seepage Flow Of Tailings Dam And Sustained Stability After Heightening Under Water Level Increase

Tailings Dam is used to store tailings in mining process,due to the limitations of the prior art smelting and other factors can not use the place of mine waste materials,if tailings dam unstable failure occurs,the library accumulation of mine waste material poured out,will It poses a great threat to the life and property safety of the ecological environment,staff and surrounding residents.There are many factors that can lead to unstable failure of tailings dams,of which water seepage is the main reason.Studying the stability of tailings dams under seepage has important guiding significance for controlling the normal and safe operation of tailings dams.In this paper,we take the Jiajiawan Mine of the Changning City as the reference object of the actual project.While obtaining the relevant engineering geological data of the tailings reservoir,combined with the analysis of on-site monitoring data,we use the GEO Studio simulation software to establish the corresponding simulation calculation.Analyze the model to analyze the static seepage flow of the tailings dam,the seepage analysis under the water level fluctuation,and the stability analysis and calculation under consideration of the fluid-solid coupling in the tailings dam heightening project,supplemented by reliability analysis.A comprehensive assessment of its safety and stability,and ultimately based on simulation and calculation results to derive the main conclusions and make reasonable recommendations.The main research contents of this article are as follows:1.According to the above data,a tailings dam simulation analysis model was established to analyze the changes of the saturation line and pore water pressure of the tailings dam under six different conditions through the “seep/w” module,and the variation of the pore water pressure to the rising speed of the water level was obtained.It is more sensitive,the safety factor is affected by the height of the water level rise,and the saturation line is similar to the change trend of the safety factor;the variation of the saturation line obtained from the simulation is compared with the monitoring data of the actual tailings dam saturation line,and it is found that the simulation calculation The tailings dam saturation line is well fitted with the monitored tailings dam saturation line,and the seepage analysis results are of significance for reference for actual projects and can be used in subsequent analysis.2.Set up the simulation model of tailings dam,analyze the changes of the saturation line and pore water pressure of the tailings dam under six different working conditions through the seep/w module,and conclude that the change of pore water pressure is sensitive to the speed of water level rise.The safety factor is greatly influenced by the height of the water level rise,the conclusion that the saturation line is similar to the change trend of the safety factor;the change of the saturation line obtained from the simulation is compared with the monitoring data of the actual tailings dam seepage line,and the tailings calculated by simulation are found out.The saturation line of the dam is well fitted with the monitored saturation line of the tailings dam.The results of the seepage analysis can be used for reference in the actual project and can be used for subsequent analysis.3.Based on the results of seepage analysis,a tailings dam heightening design scheme was adopted to calculate the stress and deformation of the tailings dam in the case of fluid-solid coupling through the sigma/w module.A stability analysis model based on fluid-structure coupling was established to check the stability and safety factors of the tailings dam after normalization under normal operating conditions and flood operation conditions.4.On the basis of the above results,taking into account the defects in the calculation of the safety factor of the fixed value to take into account the variability of the dam material,the reliability analysis method is used to supplement the evaluation of the stability of the tailings dam,so as to fully and objectively reflect the tailings dam's real state of stability.Based on the above research work,this paper summarizes the regularity of the change of the saturation level of the tailings dam with the reservoir level.,and the influence of the height difference and velocity of the reservoir water level on the stability of the tailings dam,and calculates the tailings dam through the calculation of the fluid-solid coupling theory.The stress and strain conditions are used to evaluate the impact of tailings dam heightening on the stability of the tailings dam.Finally,according to the conclusions,reasonable suggestions and preventive measures are proposed.