Study On The Influence Of Rainfall On The Stability Of Tailings Dam

Whether the tailings pond is in a safe operation state is of vital significance in the production of mining engineering enterprises from the past and even at present.With the continuous improvement of the current technology,the tailing sand particles become more and more fine in the process of generation,the tailing materials are more and more complex,and the height of the tailings dam is higher and higher.In many tailings pond accidents,rainfall has a serious impact on the tailings pond.Heavy rain or continuous rainfall is an important reason for the deformation and dam break of the tailings pond.Once the accident occurs,it will cause irreversible great harm to the downstream people and the surrounding environment.To sum up,it is not only rich in academic value to study the distribution characteristics of seepage line of tailings reservoir under different rainfall conditions and its influence on the stability of tailings dam body,but also the most important social,economic and social benefits.(1)Through the field investigation and the survey data provided,the basic information of the topography,geomorphology,geology and hydrology of the Chimou Pine tailing pond project is obtained,and various factors affecting the stability of the tailing pond are analyzed and described.On this basis,the failure mechanism under the condition of rainfall infiltration and ground motion load is analyzed.(2)The engineering geology exploration,sampling,on-site monitoring and indoor geotechnical test are carried out to obtain the stratification of tailings in the tailings reservoir,and analyze the deposition law and characteristics of different tailings as well as the physical and mechanical structural parameters of the tailings layer.Poisson's ratio,elastic modulus,internal friction Angle,cohesion,compressive strength and permeability coefficient of rock mass are obtained,and these parameters are used to provide reference for the next numerical modeling.(3)The finite element software was used to conduct two-dimensional and three-dimensional numerical modeling of The Chimox Pine tailings pond,and the analysis model was applied to different rainfall intensity(25mm/ 1d,50mm/ 1d,100mm/ 1d,200mm/ 1d);Different rainfall duration(25mm/1.5d,25mm/ 3d,25mm/6d);The seepage field changes under the same total rainfall(25mm/ 6d,50mm/ 3d,100mm/1.5d,200mm/0.75d)(different rainfall intensity,different rainfall duration)and the strength reduction method is used to analyze the tailings pond stability.From the analysis of the above situations,it can be concluded that in the above three working conditions,with the increase of rainfall intensity and the increase of rainfall duration,the pore water pressure will increase and the rate of tailing pond stability decline will increase.The pore water pressure in the tailings pond is more obvious,the matric suction of the tailings in the tailings pond also shows a downward trend,and the stability of the tailings pond also shows a downward trend.(4)By simulating the actual local basic seismic fortify intensity standard,and under the condition of ground motion load,the variation law and stability of displacement field,stress field and effective plastic zone of tailings pond under the effect of applying seismic peak acceleration 0.05 g and seismic wave are analyzed.The analysis shows that the area range of the effective plastic zone belongs to a relatively small range according to the whole tailings pond model,and the effective plastic zone produced does not achieve the effect of breaking through,nor does it show the trend of breaking through.The calculated minimum safety factor is 1.831,which appears at2.2s.In this way,it can be shown that the tailing pond will not be unstable when the peak acceleration of the earthquake is 0.05 g.(5)Measures and suggestions to improve the stability of the chimou Pine tailing pond are given under the condition of rainfall infiltration and ground motion load.