Spalling prevention technology of delta area in high cutting coal mining face

Acording to the stress concentration and the serious mine pressure bunp behavio in the delta area of the high cutting coal mining face and the large are saling and other problems ocured in the mining process,the theoretical anaysi sie measurement industrial trial and other methods were applied to analize the failure mechanism ofthe delta coal of the oo at the face end ofNo.1308 high cutting coal mining face and the adivance supor rssure infuence scope and falire soopeofthe high cuttig mining face which could povide the basis to the salling preventio and conrlwih the rational grouting rea grouting opporunty and the groutparameter selection.The study resuts showed that the infuence scope of the advance suppor prssure was 35 m,the maxinfuence areawas at s m infrontofth coal mining face and the max value of th suppor pressure wa 2.3 MPa.The new inorganic grout material had a no separation and no shrinkng,high seting rate of 100% and other advantages and could obiously inprove the seam inegity and stailty, Thus the salling depth could be reduced by 0.5~ 1.6 m in average and the grouting effect was obvious.