| With the increasing demand of society for mine resources,the mining of minerals must be accompanied by the production of tailings.Permeable rockfill dam is widely used as an initial dam in tailings reservoir because it is composed of rockfill body and reverse osmosis body and has the advantage of pervious filter slag.The stability of tailings dam is related to the safety of life and property of downstream people and the environment around mines.Therefore,the stability of pervious rockfill dam has gradually attracted people’s attention and research in recent years.Based on the background of Beigou tailings initial dam,this paper studies the causes of stability and instability risk of pervious rockfill dam;conducts qualitative or quantitative analysis of the risk indicators causing the stability of pervious rockfill dam itself;and establishes the risk evaluation model of pervious rockfill dam to formulate a risk early warning scheme for Beigou tailings dam.It plays a preventive and early warning role for the occurrence of accidents and has practical significance for the safety evaluation of pervious rockfill dams.The main contents and conclusions of this paper are as follows:(1)During the construction of permeable rockfill dam,the quality of dam body is determined by the construction quality of dam foundation excavation and dam body filling.Measures should be taken to strictly control the construction quality of dam body from five aspects: construction technology,dam material,engineering quality,operation quality and personnel quality.(2)The causes of tailings dam instability accidents are complex.Statistics show that the major factors affecting dam stability are hydrogeology,survey quality,construction conditions,drainage seepage and backleaching,flood discharge facilities and maintenance quality.(3)According to the safety grade of dam body,the stability of dam body is divided into four grades.According to the characteristics of each index,19 stability indices are constructed as membership functions.Qualitative indices are used to quantify or quantify the safety grade.Qualitative indices are used to give the evaluation basis of grading criteria.Quantitative indices are used to give the numerical range of grading indices according to relevant standards and industry standards.(4)On the basis of matter-element extension model,the stability evaluation model of pervious rockfill dam is established.The uncertain information in stability analysis of pervious rockfill dam is processed by unascertained measure,and the single index weight is calculated by entropy weight method.The improved matter-element extension model is objective and accurate in evaluating the stability of Beigou tailings dam.The safety early warning and prediction scheme of Beigou tailings dam is formulated to strengthen safety management and improve its standardization and standardization level.This paper clarifies the influence degree of factors such as dam construction quality on stability,provides reference for risk analysis and evaluation of the stability of pervious rockfill dam,and provides reference for the study of dam stability management. |
