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.1605 coal mining face in Pinggou Mine,the safety danger conditions could be occurred to the borehole drilling operation.With the theoretical analysis on the coal mining face in a non protected area and the analysis on 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 spraying were found.Based on the circumstances,the countermeasures to prevent and control the hole spraying were provided and thus a safety successful construction of the borehole drilled along the seam of the coal mining face could be ensured.