Stability Analysis Of Jianshui Miandian Tailings Pond Under The Condition Of Rainfall Infiltration

As a special hydraulic structure,Tailings reservoir is an important structure to maintain the normal production of the mine.Most of the tailings in the reservoir contain toxic and harmful substances.Most of the tailings in the reservoir contain toxic and harmful substances.In the event of a dam break,in addition to causing casualties and property losses,it will also cause serious environmental pollution,which directly affects the safety of downstream residents and the safety of public facilities.Therefore,it is of great significance to study the safety of the tailings pond.The Jianshui Miandian tailings reservoir is under closed reservoir construction,its downstream conditions are complicated.The original dam safety factor fail to meet the specification requirements under special operating conditions,it is urgent to strengthen the dam body and study its stability.This paper takes the Jianshui Miandian tailings reservoir project as a research object,analyzes the engineering geological and hydrogeological conditions of the Jianshui Miandian tailings reservoir in Yunnan reference field survey results and engineering survey data.Based on theoretical analysis and laboratory experiments,seepage characteristics of tailings,the basic differential equation of three-dimensional seepage,and the interaction mechanism between the tailings reservoir seepage field and stress field are analyzed.Finally,the stability analysis of the tailings reservoir under the rainfall conditions is studied in depth by means of numerical simulation software,The main research results of this paper are as follows:?1?On the basis of particle size distribution case,the tailings sedimentation law is analyzed,and the effects of tailings thickness and compactness on the tailings permeability characteristics are investigated through the laboratory penetration test.The test results show that the hydraulic conductivity of the tailings is positively correlated with the characteristic particle size d₅₀ and negatively correlated with its density;the thickness and the compactness of tailings have a certain effect on the hydraulic conductivity,but the compactness has a greater effect.?2?Applying basic knowledge such as soil mechanics,hydraulics,and advanced seepage mechanics,combined with the actual situation of the tailings reservoir,the basic differential equation of three-dimensional stable seepage of the tailings dam and its solution conditions are elaborated;the coupling mechanism of seepage field and stress field is analyzed while the expressions of indirect coupling and direct coupling of seepage field-stress field are obtained through detailed mathematical derivation,which more intuitively reflects the interaction and mutual influence between stress field and seepage field.?3?With the help of Flac-3d numerical simulation software,the stability of tailings reservoir under different conditions is calculated,the effect of rainfall on the stability of the tailings reservoir,the impact of buttress's reinforcement to tailing dam as well as the influence of drainage hole on the stability of tailings reservoir are analyzed.The results show that:in the initial state,there is no water in the reservoir,the horizontal stress value and vertical settlement are small,and it is in a stable state;after the rainfall is applied,pore water pressure occurs in the reservoir,the horizontal stress value and the vertical settlement in the reservoir both increased,there is a slight stress concentration at the bottom of the tailings reservoir and the initial dam has the risk of overturning;when the initial dam is reinforced there is no significant change in the pore water pressure in the reservoir under rainfall conditions,the horizontal stress and vertical displacement in the reservoir are reduced,and there is no risk of overturning in the initial dam;after draining the initial dam,,the pore water pressure in the reservoir is obviously reduced under the condition of rainfall,and the horizontal stress and vertical settlement are reduced,while additional drainage facilities,most of the lower seepage water is discharged along the drainage hole,which plays a good drainage effect and thus improves the overall stability of the tailings reservoir.