Study On Mine Pressure Regularity And Control Of Hard Roof Working Face In Qidong Mine 8₂22

In the coal mining in our country, the occurrence of hard roof in coal mines accounted for about 30%. There are many outstanding problems in the control of hard roof, for example,no support space to expand,unable to achieve effective working resistance,support structure instability,support equipment damage,easily causing shock pressure, etc.This paper takes the 8222 working face of Qidong mine as the research object.It’s roof is hard roof. Through the analysis of geological data and mining condition, the theoretical analysis and the similar simulation method, the study of the deep hole pre splitting blasting is made,it can get the first caving step distance 55.3m, limit span 55.2m and periodic weighting step distance 22m;and risk falls with the height of 10m, about 3.8 times the working face. The first caving step distance is 35m and the hanging roof length of 17m, calculate the reasonable blasting cycle step for 17m. Blasting caving height is more than 10 times mining height, blasting in the 81 and 82 layer key layer, hole spacing should be less than 20m.The results of the study as hard roof control provides theoretical basis and practical reference value, and the control of hard roof has a certain guiding significance.