The Caving Stope Below The Filling Stope Of Chengchao Iron Mine Stability Analysis And Roof Security Controle

With the continuous exploitation of mineral resources by human society,near-surface resources are gradually becoming scarce,and the exploitation of underground mineral resources is gradually transferred to the deep,so it is facing a series of problems.With the trend of ore body,the stope of Chengchao Iron Mine gradually expands to the West and the deep.Before the relocation of the concentrator,the security pillars were mined by filling mining method.Now the concentrator has been relocated.The mining of the security pillars under the filling stope has been restored to the caving mining method with large output and high efficiency.Therefore,the new mining method faced complex mining face.The roof structure causes problems such as uneven distribution of stress in the mining site and high concentration of local stress,which threatens the new level of mining.Therefore,in view of the special working condition that Chengchao Iron Mine is changed to caving mining under the filling stope,this paper analyzes the ground pressure distribution law of the stope by means of computer numerical simulation,laboratory similar experiment and theoretical research,explores the stability of the stope,and puts forward the safety countermeasures in line with the actual situation of Chengchao iron mine.Firstly,an indoor similarity model is established in combination with the typical section of the west mining area of Chengchao Iron Mine to simulate and study the general surrounding rock deformation law of the stope before and after the excavation of the prospective roadway and identify the dangerous area;Analyze and summarize the stress distribution of the mining site,and use mechanical numerical simulation software to simulate the mechanical behavior of the overall and local roadway under mining conditions,and explore the deformation and failure characteristics of the mining roadway under different roof rock and different stress distribution conditions Laying the foundation for the proposed measures;Based on the above research results,considering the reliability and economy,a fuzzy evaluation model of the roadway support system is established to optimize the support scheme.The test results show that the deformation of the surrounding rock under the mining roadway is larger than the surrounding rock under the caving body.The stress environment is more complicated and the stress concentration is more obvious.There is a concentration of tensile stress on the bottom plate,plastic deformation on both sides of the top and bottom plates is obvious,shear damage is easy to occur,and the deformation of the two gangs is relatively small and relatively safe.After optimization,the supporting scheme for the mining roadway under the stope is as follows: anchor and shotcrete support,7 anchor rods with a spacing of 700 mm are selected on the top,two anchor rods are used for the two gangs,and inclined anchor rods are added at the bottom angles of the two gangs Among them,1#,2#,9# ? 13# anchor rods are extended anchor rods with a length of 2500 mm,3# ? 8# anchor rods with a length of 1800 mm,a spray layer thickness of 80 mm,and a row spacing of 900 mm.