Abstract: Due to the low permeability,long time operation and poor effect of gas drainage for coalbeds in Xuehu coalmine,the hydraulic punching in crossing holes of floor roadway in the 2306 pannel in Xuehu coal mine is applied to improve the effect of gas drainage.The wear layer drilling holes arrangement design of hydraulic fracturing extraction is analyzed in detail from the aspects of drilling,fracturing process and fracturing anti-reflection extraction gas outburst elimination effect.The results show that the coal porosity,plasticity,moisture and water permeability are improved by the application of the hydraulic punching technique in cross-measure boreholes,besides that,the physical and mechanical properties of coal are also changed,the gas drainage rate is improved obviously.Therefore,the problems of the concentration of construction and excavation,the study results of the paper can provide the practical experience and theoretical basis for the ensuring the high yield and efficiency of coal mine.

Key words: Drainage lane of floor, Drainage of crossing hole, Outburst hazard elimination, Hydraulic punching, Permeability