Control Technology for Hard Roof of Variable Spacing Overburden Rock in Extra-Thick Coal Seam of Zhuxianzhuang Coal Mine
The lagging collapse of the extra-thick and hard roof of the coal seam poses a significant threat to the mining face.Usually,advanced pre-splitting measures are taken to reduce the span length of the roof.Taking the management of the extra-thick conglomerate roof at the 8831 working face of the Zhuxianzhuang Coal Mine as the research background,key control areas of the extra-thick roof were identified based on the distance variations between the coal seam and the extra-thick conglomerate.On the basis of the structural analysis of overburden strata in extra-thick coal seam,the given load of the roof was obtained,the influence of the variation of the interlayer distance on the mining pressure was analyzed,the control target layer of overburden strata was determined,and the spatial layout parameters of boreholes were designed.By using high-performance coal mine water-gel explosives combined with multidirectional cumulative tubes and grouting sealing technology,deep hole blasting technology practice was carried out on the hard roof of coal seams,achieving good cracking effect of hard roof blasting.The deformation of the surrounding rock of the mining roadway and the manifestation of mining pressure on the working face were effectively controlled.
Extra-thick coal seamHard roofOverburden structureDeep hole blastingDeformation of the surrounding rock
万方数据
维普
