Seismic Stability Analysis And Safety Evaluation Of Tailings Dam In Qinglong Area

Tailings dam as a structure to store water and tailings.Actually,the tailings dam can be regarded as a man-made dangerous area of debris flow with relatively high potential energy.If the tailings dam breaks down,it will seriously threaten the safety of downstream residents and facilities.It is of great engineering significance and theoretical value to consider the stability of seismic action after the initial seepage of tailings dam.In this study,three typical tailings dams in the Qinglong Manchu Autonomous County of North China were used as the engineering background.Through the analysis of the stability calculation results,an empirical fitting formula was proposed.The formula considers the relationship between safety factor,permanent displacement and influencing factors,and the scientificity of the formula is confirmed by actual engineering.Firstly,the geological environment conditions and seismic activity background of Qinglong Manchu Autonomous County in North China were introduced.The three dams of the Quntai Iron Mine tailings dam,the Guanshan Iron Industry tailings dam and the Huiming Mine tailings dam were research object.Based on the nonlinear finite-difference software FLAC3 D,a three-dimensional solid model was established to analyze the stability of the dams under the natural state and initial seepage of different water levels.Secondly,the stability of earthquakes based on the initial seepage is studied.The effects of different internal and external factors on the stability of the tailings dam are described,including the seismic intensity,the duration of the earthquake,the length of the dry beach,the slope gradient,the cohesive force,the internal friction angle,etc.Through the setting of key monitoring points,the common change laws of response acceleration,response displacement and safety factor of tailings dam are analyzed.Furthermore,considering the many uncertainties existing in the tailing dam safety evaluation process,the unascertained measure theory is applied to introduce the unascertained safety evaluation of tailings dam,and evaluate the safety of tailings dam under the earthquake condition.The preliminary identification of the Shenjiashan tailings dam in the Qianxi County,Hebei Province,was carried out.Finally,the numerical simulation results and laws were analyzed and consolidated,and a quantitative evaluation system for seismic stability after initial seepage was constructed.The Shenjiayu tailings dam was still used to verify the rationality of the evaluation system.This evaluation system intuitively and accurately expresses the stability of the tailings dam from a quantitative perspective,which can be used as a supplement to the unascertained evaluation,and also provides a theoretical reference for the safety management of other tailings dams.