Study On Upward Coal Seams Movement And Feasibility Of Ascending On The Condition Of Pillar Mining

Under the background of the actual geological and pre-production inTongshengjingtongxingwang coalmine, the use of field research and practice,the method of theoretical analysis and numerical analysis of the activities underthe laws of the overburden the lower room and pillar coal mining conditionswere studied. Based on this analysis and the upper part of the lower coal seamby the extent of room and pillar mining mining influence, demonstrate thefeasibility of upward mining.For a comprehensive analysis of the lower seam different room and pillarmining effects on the overlying strata movement, based on the actual productionof coal mine combined, the paper analyzes the use of orthogonal principle,taking into account the mining width, leaving the main factors of coal pillarwidth, etc. degree of stability and the impact of the activities of the overburdendeformation, Numerical Simulation of stay than the two factors affecting miningwidth on the12th of room and pillar coal mining, on this basis, on the9th of theupper coal seam using stepwise numerical simulation of excavation, lower partof the study room and pillar mining and coal mining upper coal seam up theprocess, leaving more than mining, and other factors affecting mining width ofroom and pillar coal pillar and the overburden deformation events. The mainfindings are as follows:1. When picking stay within1/2to2ratio range, mining width remainsunchanged, mining and reservation ratio, the stress is more likely to focus oncoal pillar stability pillar worse than mining remain unchanged, the larger mining width (the width of coal pillar left), the better the stability of coal pillar,bearing ability. Upper coal seam extraction process, the secondary effects ofmining will further affect the stability of the pillar, supported by the leading roleof the pressure, in the steady state limit instability of coal pillar collapse easily.2. The lower part of the room and pillar mining coal seam stressdistribution after the formation of "booster zone" and "relief area" appearalternately, so that the overburden activities have different degrees ofdeformation; when mining than stay in the range of1/2to2when mining widthremains unchanged, leaving mining than smaller alternating stress distribution,the more obvious the more easily formed within mining width wave, miningwidth bigger waves more obvious. Abutment pressure affected the uppersecondary coal mining will further exacerbate alternating distribution, furtherdevelopment of the wave up.3. Through theoretical analysis and numerical simulation, with the studentsproficient on the9th booming coal seam fracture zone in the lower coal seamafter the balance on rock, rock structure can be formed without the risk levelequilibrium dislocation, in the12th seam upper goaf upstream coal mining onthe9th.