Study On Dynamic Stability Of A Tailings Pond Under Earthquake

Tailings pond is used for storage of metal and nonmetal mine ore selected don't back out of the tailings.Downstream of the tailings pond often have villages,factories,farms and other important facilities,once the tailings dam break,it will seriously threaten the safety of downstream life and property,resulting in huge losses.At the same time,China is a multi earthquake country,the earthquake is a major factor in the tailings dam break.Therefore,the present paper selects Lazigou tailings pond in Chengde of Hebei province as the research,In this paper,The main work is carried out on the dynamic stability of tailings dam under earthquake action as follows:(1)The basic situation of tailing pond is described and summarized,the ge ological condition and seismic effect of the tailing pond are described in detail,and the stability analysis of the two sections is also carried out.(2)In the static stability analysis of the dam,the incremental method is used to consider the nonlinear properties of the soil,and the stress-strain relationship of the soil is E-v model with Duncan-Chang model.In the two sections of the tailings pond selects from eight kinds of conditions,using the finite element software to calculate each section under different conditions of maximum principal stress,minimum principal stress,shear stress,horizontal displacement and vertical displacement,according to the calculation results under different conditions,it can be judged that the dam is in steady state under the static action.(3)This paper uses step by step integration method in time domain for dynamic analysis in accordance with the equivalent linearization method,selecting two measured seismic waves and one synthetic seismic waves from the input earthquake wave and using the finite element software to calculate the dynamic response of the X,Y direction node acceleration,the maximum and minimum principal stress and the X-Y dynamic shear stress in two different sections under eight different conditions.According to the graph can be seen on the top and base level surface acceleration response is the largest,the largest vertical acceleration response in the dam surface.In order to obtain the changing trends of acceleration,dynamic shear stress and displacement with time,corresponding time history diagrams are drawn under the same conditions.According to the relevant figures,we can get that the acceleration and the dynamic shear stress is relatively small,and there is an increasing tendency,and the earthquake has great influence on the displacement of the dam.The maximum displacement occurs at about 3/4 height of the dam slope.(4)Basing on the analysis of the tailing sand dynamic test and seismic response,according to the two section and four working conditions,the influence of the numerical value of the relative compactness in the same section under the same condition on the distribution range of the liquefaction area of the dam section is calculated.Elcentro wave,Taft wave and synthetic seismic wave are used to analyze the liquefaction of tailing pond,three kinds of seismic waves are similar to the distribution law of liquefaction area and the result of calculation is relatively concentrated,this shows that the seismic wave selection is reasonable,at the same time shows that the stability of the calculating program.Through the finite element software to calculate each section of the two sections to determine under three different seismic waves that after the earthquake occurred the residual deformation of tailings minimum freeboard and the minimum length of dry beach meet the specification requirements.(5)The risk factors and main reasons for the occurrence of tailings dam are summarized.Putting forward the measures to strengthen the field management.,and the effective management system is established to ensure the long-term safety and stability of the tailing pond.