Analysis Scheme Pillar Mining Under Complex Conditions And Levels Of Stability

In the process of underground ore body mining,a various types of pillar should be left for avariety of technical reasons.including a typical one: level pillar, which is important in keepingstope stability and the control of strata pressure. But as the orebody mining, level pillar of thethin plate structure may produce instability, causing catastrophic accidents.therefore, analysis ofthe stability of level pillar and evaluation of the type of mine will have a reference value.withlevel pillar of anqing copper mine-385-m of as the engineering background, this article usestheoretical analysis, in-situ monitoring and numerical simulation technology to study and analysethe stability of level pillar. in this paper, the main research contents and conclusions are asfollows:1,Do the brief analysis of the characteristics of mining area geology situation, joint, thestability of rock mass, ground stress. Get three sets of main mining area of rock mechanicsparameters through the indoor experiment of rocks, then combine it with elastic wave method,Hoek Brown method and folding subtraction on rock mass mechanics parameters for theengineering processing, and get the mining rock mass mechanics parameters, for reliable basis ofsubsequent theoretical research and numerical simulation.2, According to the stress characteristics of horizontal pillar, use the catastrophe theory toestablish the cusp catastrophic model,get instability conditions of the level pillar, the conclusionshows that theory thickness of instability of level pillar is almost zero. Use thin plate theory andultimate tensile and get the relationship between the stope span and reserved thickness of levelpillar3,Use secondary stress and displacement monitoring and ground penetrating radar (GPR)nondestructive detection means for on-site monitoring of the stability of level pillar. Stressmonitoring data show that the large and thick ore body in western region produces a certainamount of stress concentration and stress at the ends shows the stable. Displacement monitoringdata shows the stable and absolute value is small, on the macro,large-scale ground pressureactivity is never to appear. Ground penetrating radar (GPR) data shows that horizontal pillar is acertain damage, but the stability of the overall is good.4, Using FLAC3D numerical model, analyse mechanics effect on level pillar of lower partof ore body mining and the accumulation of ore body mining, from the aspects such asdisplacement, stress and plastic zone. Make the preliminary choice on level pillar stopingmethod, then put forward four kinds of solutions on stoping sequence. Through comprehensiveanalysis of four kinds of solutions ondisplacement, stress and the size of the plastic zone after mining, get the conclusion that the optimal recovery sequence is from two wings to the middle of stoping, which provides thereliable theory basis for pillar stoping.