Research On Mining Gateway Under Goaf Supprting Technology In Yangwangou Mine

Roadway layout and supporting is an important problem in the study of mining engineering, facing the grim reality of coal demand increasing and the coal resources exhaustion, how to layout and support reasonably in the old mined-out area, to recycle resources early caused by the irrational exploitation,which has the real significance and practical value to study on the proper exploit methords.Applying theoretical analysis, engineering analogy, numerical simulation and field test to research roadway support problems gob area on6seam6203working face in Yangwangou coal mine, analyzing surrounding rocks stability under goaf, according to the pressure arch theory and the supporting pressure band theory, it points out that the air return roadway should be arranged in the stress decreasing zone under goaf. Through elastic-plastic theory analysis, also combining the results on theoretical analysis and numerical calculation, it is proved that the rational coal pillar width should be in25m; Through engineering analogy analysis based on loose circle theory, it is determined that the roadway uses compound supporting way, that is the bolt net adding steel shed.Through analyzing field measured data,it is known that the air return roadway arranged in stress decreasing zone under goaf, after3-4weeks later, the roadway displacement in two help and roof subsidence are stable in the control scale about43mm and50mm.By bolt pullout test,the bolt pulling level is in40kN-50kN, achieving design intensity range. Through detecting bolt pretightening force, the bolt should be tightened again in broken surrounding areas, so that the anchoring force reaches15MPa. From the analysis above, air return roadway supporting scheme under goaf satisfies the requirements on safety and high efficiency in recoverying coal resource.