Physical And Mechanical Properties Test Of Tailing Sand And Stability Analysis Of Excavation Slope In Huibaoling Iron Mine

Tailings are "waste" discharged by mining enterprises under certain technical and economic conditions,but at the same time they are potential secondary resources.Tailings mining is of great significance for making full use of non-renewable mineral resources.However,once the tailings slope is unstable when mining tailings,it will cause significant economic losses and casualties.How to ensure the safety of the tailings sand excavation process has important guiding significance and social value for the actual project.In this paper,the safe excavation of tailing sand in Huibaoling Iron Mine is taken as the research object,the physical and mechanical test of tailing sand is carried out,the physical and mechanical parameters of the tailing sand are obtained,and the deformation and failure characteristics are analyzed.Using FLAC3D software,the numerical calculation model of tailings slope is established,and the influence of various factors on the stability of excavation slope is analyzed.The main research content and achievement include:(1)Analyze the factors that affect the safe excavation of tailings sand,such as the environment,mining process and accumulation characteristics of the ore sand,and summarize the safety analysis method.Intuitive interpretation and stress analysis.(2)The physical and mechanical parameters of the sample were determined through physical and mechanical tests on the tailings sand.It can be seen that the sample taken in the test belongs to fine powder of tail powder.When the moisture content of the sample is extremely small,the bulk density of the sample reaches its maximum,and the permeability coefficient of the tailings sand decreases linearly with the increase of the dry density of the sample.Under certain dry density conditions,as the moisture content value increases,the shear strength index of tailings sand will also increase linearly with it.Through the triaxial compression test of the tailings sand sample,the stress-strain curve and the variation of stress-strain with the confining pressure are obtained.(3)Taking the Huibaoling tailings slope as a geological prototype,the tailings slope after generalization of typical profiles was selected for numerical simulation,and the excavation slope rate,slope top load strength,stepped method,anchor reinforcement and different water content were studied respectively Stability during excavation of lower tailings sand.Through FLAC3D software and the strength reduction theory,the numerical simulation of tailing sand slope excavation is carried out.It can be seen that during tailing sand excavation,the excavation slope rate,slope top load strength,stepping method and anchor reinforcement do indeed affect the tailings slope body Stress and deformation development have an impact.However,compared with the general soil slope,the tailings sand slope is more sensitive to slope rate,load and reinforcement,and the change of safety factor is smaller for the staged excavation and the change of water content.