Numerical Simulation Analysis Of Stability Of A Tailings Dam In Hunan Based On PFC Under Earthquake Action

Because of the frequent earthquake activity in China and the extensive distribution of tailing reservoir,the safety and stability of the tailing dams have become the focus of the tailing dams research.The change of related mechanical parameters of tailing dams under earthquake action is related to the safe operation of the whole tailing dams.It is also related to the safety of tens of thousands of people's lives and property,and the protection of social ecological environment.Therefore,a tailing dam in Hunan Province as the research object was studied.According to the functional characteristics of the particle flow software,the dynamic simulation and the time step display calculation algorithm of PFC2 D software were used to simulate the effect of seismic wave on the stability of the tailing dam,and analyzed the location and development trend of the damage of the tailing dam under the action of the earthquake.The main research work and achievements of this paper are as follows:(1)According to a specific example of tailing dam,PFC2 D is used to simulate the relevant parameters of seepage coefficient under seismic action and the change of stress and displacement at different positions.The simulation results show that the seepage coefficient is independent of the time interval of the model and the apparent volume of the domain,but the relationship between the seepage coefficient and the conductivity is not proportional to the particle pore ratio.With the earthquake loading,the tailing dam gradually slips during the earthquake action,and the maximum sliding position of the X direction appears at the measuring circle 8,that is,the upper part of the upper part of the bedrock near the coarse sand and the maximum value is 1.8872 m;the maximum sliding position of the Y displacement appears at the measuring circle 1,that is,the lower base rock is near the initial dam.Part,the maximum value is 0.9346 m,the larger displacement of bedrock is relative to the tailing dam.(2)The analysis of the stress and strain curves in the tailing dam under the earthquake action is an important part of the safety and stability analysis of the whole tailing dam.The simulation results show that the seismic slip part under the action of the whole tailing dam is lower after first produced large displacement above the sliding,which caused the overall local slip slip dam;initial dam and fine sand relative to the bedrock is prone to slip and slip displacement obviously,compared with the fine sand coarse sand is easy to produce displacement.(3)Based on the numerical model,the maximum displacement of tailing dam after sliding and the judgement of the instability failure of tailing dam are studied.At the same time,the failure trend of the tailing dam under earthquake action is explored.The change of the displacement of the tailing dam changes with the change of the seismic load and the maximum change is located at the foot of the slope.The displaced cloud chart shows the stratified failure surface,which indicates that the tailing dam has been in a state of destruction.Through the analysis of the numerical model of the tailing dam,the safety performance of the tailing dam under the action of the earthquake is judged,and some examples are provided for similar projects.(4)The numerical simulation results show that the tailing dam toe is the most prone to obvious slip through the method of seepage drainage reinforcement comprehensive comparison and selection,the horizontal location of radiating well in the saturation line is 50 m,150m,250 m,350m and 450 m,which can reduce the height of the saturation line to varying degrees.