Cause and Countermeasures of Hole Spraying from Borehole Drilled Along Seam of No.1605 Coal Mining Face in Pinggou Mine

According to the hole spraying occurred during the regional drainage borehole drilling along seam of No.1 605 coal mining face in Pinggou Mine, the safe ty danger conditions could be occurred to the borehole dilling operation.With the theoretical analysis on the coal mining face in a non protected area and the analysis 0 n the stress distribution law of the stress field over the coal mining face, seam deposit variation, borehole drilling technique and other factors, the causes of the hole spr aying were found.Based on the circumstances, the countermeasures to prevent and control the hole spraying were provided and thus a safety successful construction 0 f the borehole drilled along the seam of the coal mining face could be ensured.