我矿进行煤体注水初期是在回风巷用岩石电钻沿煤层倾斜向下钻孔。由于煤质松软,容易塌孔,钻孔最深只达19米,相当于采煤工作面斜长的六分之一,远远达不到全面充分湿润的要求。近两年来,随着矿井生产不 In the early stage of coal mine water injection, mine used rock electric drill to return borehole down the coal seam. As the coal is soft and easily collapsible holes, drilling the deepest only up to 19 meters, which is equivalent to one-sixth of the inclined length of the coal face, far below the requirements of full and adequate wetting. In the past two years, with mine production not