Abstract:

because of the large thickness of main roof, the dense hard, not easy caving stoping process, easy to form a large overhang. To reduce roof hanging area, to reduce the roof caving step distance for the first time, to prevent or weaken the work top corner gas overrun and preventing top-coal and roof during the preliminary extraction caused by the large area caving working face gas overrun it is necessary to weaken the roof. According to the geological and mining conditions of 1311 face and strata structure characteristics, determined the pre-splitting blasting scheme and related technical parameters. Cut the practice results show that the use of the eye as a group as a unit for construction of blast hole, by optimizing the blasting scheme makes the hole at the bottom of the uniform distribution on a straight line, through field observation and analysis to pressure indicators, pre-splitting blast proof roof can effectively weaken the first pressure strength and to realize safe mining.

Key words: Pre-splitting roof, Effect analysis