Study On Safety Mining Stage Height Of Multilayer Deposits

When multilayer deposits are mined, the different seam mining has stressdisturbance on the adjacent seam, disturbance of the original rock stress field bringsadverse effect on mine safety production, pressure management, mining engineeringarrangement.Reasonable stage height and mining sequence is one of the effective ways toprevent and reduce disturbance characteristics between adjacent seam disturbances ofmultilayer deposit. By analyzing disturbance characteristics between adjacent minestratums during mineral deposit mining, the analytical formula is established betweensafety stage height and the rock movement angle, the orebody dip, the spacing of minestratums. Base on this, the iinfluence discipline is studied between the stage height ofmultilayer deposits and all factors. Safety stage height H of mining the lower ore afterthe upper ore increases with the increase of the spacing of mine stratums a and rockmovement angle γ1. Safety stage height H decreases with the increase of orebody dip α2.Safety stage height h of mining the upper ore after the lower ore increases with theincrease of the spacing of mine stratums a, rock movement angle β2and orebody dip α1.The effect of occurrence factors on the safety stage height of multilayer deposits isstudied by the orthogonal range analysis considering three factors. The influence degreeof all factors on the safety stage height H have been ranked as: orebody dip α2,thespacing of mine stratums a, rock movement angle γ1. The influence degree of all factorson the safety stage height h has been ranked as: the spacing of mine stratums a, orebodydip α1(rock movement angle β2).Based on characteristics of safety stage height under different occurrenceconditions, the study discussed the choice of stage mining method, hierarchical miningmethod and segmentation mining method and safe mining sequence between adjacentseams in the same stage, when two layers of ore body were mined from top to bottom atthe same time or the lower ore was mined after the upper ore or the upper ore wasmined after the lower ore of tilt-steeply inclined multilayer ore body under differentoccurrence conditions. Mining methods for mining safety of multilayer deposits underdifferent occurrence conditions were investigated. Based on disturbance characteristicsbetween adjacent mine stratums during mineral deposit mining, this study establishes analytical formula between safety stage height and the rock movement angle, theorebody dip, the spacing of mine stratums, which provides a theoretical reference formining safety of multilayer deposits.