Study On Roof Control Technology Of Expecial Incompact "Three-soft" Coal Seam Working Face

In recent years,our country have done much research on roof control technology of coal seam working face which is difficult to mine,although we have got a certain achievement,there are also a series of problems.Most controlling design of roof depends on experience,this kind of method has the nature of limitation and blindness, it is hard to control the roof safely,what's more,it often brings the consequence of much accident from roof,low efficient of supporting,bad economic efficiency.To alter this consequence,it is quite necessary to work out a series of design method Of roof control.Based on a lot of data and on-the-spot investigations,the geological condition of Daliu coal mine No.2 coal seam 2103 working face and the occurrence of coal seam, to analysis theories,aiming at the difficulty of roof control about expecial incompact "three-soft" coal seam working face,in order to optimize parameters of blast-winning technology and bring forward general supporting system of hydraulic prop cooperates withπgirder,two-resisting plastic netting and wooded sticks.Paper adopts a suit of systemic measure of roof control of "strengthening the protecting of roof,protecting of floor,control rib spalling",founding on giving attention to "propping roof,protecting roof,making props steady,allowing roof to go down" and on the best important of "protecting roof".Then analysis of the paper adopts FLAC^3Dnumerical simulation and similar material simulation in order to gain weighting interval and intensity of working face roof,range of needed control strata and front abutment pressure distribution characteristic of working face via studying completely working face surrounding rock stress distribution rule of the expecial incompact "three-soft" coal seam,strata movement rule of roof and floor,abutment pressure distribution rule of working face. The rationality of control design scheme is validated by analyzing locale in order to optimize design scheme again and make coal winning safe and efficient.Results in this paper do great good to excavate "three-soft" coal seam and cracked roof management.