Three-dimensional Numerical Analysis Of Seepage And Static Stability Of Saturated Fine-grained Tailings Pond

As a special hydraulic structure for storing tailings,tailings pond has become a potential man-made hazard source due to its high potential energy.Once it is unstable,it will cause huge losses to local environment and downstream people’s life and property.Therefore,it is urgent to conduct a comprehensive evaluation on the stability of the tailings pond in the operation stage,judge whether it meets the safety requirements,and then take scientific and effective prevention and elimination measures to avoid the occurrence of safety accidents and ensure that the tailings pond is always in a stable stateThe research object of this paper is an upstream tailings pond in Jiangxi Province,where a large number of saturated fine-grained tailings are stored.Due to the difference between the actual dam slope ratio and the design documents of the tailings dam,the stability of the tailings pond is comprehensively evaluated from two aspects of seepage field and static stability by field investigation and numerical calculation.The main contents of this paper are as follows:(1)Engineering geological investigation,field monitoring and indoor geotechnical experiments were carried out to obtain the stratification of each tailings layer of fine-grained tailings,the deposition law of tailings and the physical and mechanical parameters of each tailings layer of fine-grained tailings.The water level of the saturation line observation hole and the displacement of the displacement monitoring pile of the dam body were monitored and combined with the monitoring records over the years,the current saturation line position,dam body displacement status and The variation law with dam height.(2)Based on the above geological survey results,combined with the preliminary design data and the topographic map of tailings pond,the 3D simulation model of tailings pond is established by Midas GTS NX.On this basis,the seepage field of the current dam height and the final design dam height of the tailings pond under normal and flood conditions is simulated and analyzed,and the saturation line location distribution and seepage field characteristics of the current tailings pond and the final design dam height under different water levels are obtained.(3)Based on the three-dimensional seepage analysis,the static stability of the current situation of the tailings pond and the final design dam height are analyzed respectively,and the plastic zone and displacement variation law of the current tailings pond and the final design dam height under different working conditions are obtained,and the stability of the dam body is comprehensively judged according to the safety factor calculated by the strength reduction method.(4)The three-dimensional results are compared with the two-dimensional results by using the comparative analysis method,and the differences and relations between the wetting line position,plastic deformation zone and potential slip surface distribution with the twodimensional calculation results are summarized.