Stability Analysis Of Tailings Pond With High Slope With Median Line Method

Under the situation that the safety and stability of tailings ponds are getting more and more attention,relevant practitioners have begun to try various methods to improve the safety and stability of tailings ponds.The midline method of dam construction has attracted researchers’attention due to its low infiltration line,good stability,and high seismic strength,and is the direction of future research and development.In this thesis,a middle-line method high-slope tailings pond is taken as the research object,and seepage analysis,nonlinear static analysis and dynamic stability analysis are carried out on it.The main research results are as follows:(1)Taking a middle-line method high-slope tailings pond in Sichuan Province as the research object,the relevant physical and dynamic parameters of tailings sand were obtained through seepage test,static triaxial and dynamic triaxial tests,and the test data were sorted out for simulation.The calculation provides parameters.Through the test data,it is found that the larger the particle size of the tailings sand,the larger the permeability coefficient and internal friction angle of the tailings pond.Therefore,it is proved that the tailings sand on the slope surface of the dam using the midline method is beneficial to drainage and good stability.(2)In the seepage comparison analysis,it is found that the addition of seepage drainage facilities in the tailings pond with the central line method can effectively reduce the infiltration line.The Duncan-Zhang constitutive model is used to conduct nonlinear static analysis of the centerline method accumulation dam.The overall settlement of the tailings pond is not large,but there is still a small part of the deformation exceeding 2m.Therefore,attention should be paid to engineering reinforcement and corresponding protective measures should be taken;deformation The deformation is mainly in the vertical direction,and the maximum deformation occurs at the top of the dam vertically above the initial dam.(3)Using the equivalent viscoelastic constitutive to analyze the dynamic response of the tailings pond with the centerline method of the high slope,the dynamic response of the dam body is small under the action of El Centro seismic wave,Taft seismic wave and artificial seismic wave.Under the action of Taft seismic wave,the acceleration value at 1820m of the dam crest is 2.12m/s~2,and the amplification factor is 2.16.At this time,the dynamic response of the dam crest is the largest in the horizontal direction;under the action of artificial seismic waves,the acceleration at 1820m of the dam crest is 1.90 m/s~2,the amplification factor is 2.79,and the dynamic response of the dam crest is the largest in the vertical direction at this time.(4)Through the comparison of the liquefaction area before and after the tailings pond drainage,no liquefaction area appeared on the dam slope after adding the drainage measures;the permanent deformation analysis was carried out using the softening modulus method,and the tailings pond vibrated under three earthquakes.The rear deformation is small,mainly vertical deformation,and the maximum total deformation value is 0.58m.The total deformation is mainly in the form of the upper part of the accumulation dam sinking downward and the lower part extruding upward to the empty surface.(5)Calculate the dynamic safety factor before and after the dam slope is compacted.It is found that the higher the density of the tailings material,the safer the dam body.The canonical safety value is 1.15.