Study on deep hole blasting technology in unmanned working face of steep seam

In order to solve the problems of poor drilling accuracy, slow charging speed, difficult charging and low construction efficiency in deep hole blasting technology of unmanned working face in steep seam, this paper systematically analyzes the causes of drilling trajectory deviation and depth deviation, summarizes the causes of hole collapse and the difficulties of deep hole charging based on a large number of deep hole blasting engineering cases.Through field test, the deep hole blasting technology of unmanned working face in steep seam is put forward, including borehole deviation correction, anti-collapse hole and deep hole upward charging technology, and a kind of charging blasting barrel which can meet the self-stability of the charge in the blast hole is developed.Field application shows that borehole deviation correction can be solved by reasonable arrangement of blastholes, reasonable design of hole diameter and depth, reasonable selection of drilling rig and strengthening on-site operation training; hole collapse can be effectively avoided by inserting flexible casing immediately after drilling; the problem of deep hole charging can be solved by designing upward charging blasting barrel.This technology can effectively improve the blasting progress, greatly reduce the deviation from the original design in the construction process, and play a positive role in promoting the mining technology of unmanned working face in steep seam.