Drilling Technology of Directional Drilled Borehole for Advance Grouting Reinforcement of Seam Floor

In order to improve the borehole grouting reinforcement effect of seam floor in underground mine, the paper provided a borehole floor grouting reinforce ment technical method with a drilling measuring and directional drilling technology. A systematic study was conducted on the casing drilling, rotary deflection drilling, dir ectional deflection drilling and through hole drilling technology and matched drilling tools. A drilling technical procedure was designed. The site trial results in Zhaogu N 0.1 Mine showed that the directional drilled borehole could realize the advance treatment of the seam floor, the grouting quantity of a single borehole would be increas ed by a large margin and the seam floor reinforcement effect was obvious.