Optimization of charging parameters of non-pillar roof cutting and shaped charge blasting in medium-thick coal seam
The optimization of the charging parameters of roof-cutting cumulative energy blasting in non-pillar medium-thick coal seam is investigated based on the engineering background of No.11101 transport roadway at Qipanjing Coal Mine(East Area).Through the mechanism and charging parameters of roof-cutting blasting,numerical simulation is used to verify single-hole and multi-hole blasting.Roof-cutting energy blasting parameters are designed for the engineering situation of No.11101 working face.The results indicate that the cutting rate of mainly sandy mudstone broken roof is lower than the sandstone roof and intact roof test groups.It is also found that when the roof in mud sealing section is sandy mudstone,the opening shows a certain degree of damage.The effect of the pre-cracking slit of the roof in quarry directly affects gangue filling effect in the mining area,which in turn affects the stress transfer in overlying rock layer of the quarry.The relevant conclusions are verified through on-site blasting tests,and the blasting technical parameters suitable for No.11101 working face of Qipanjing Coal Mine(East area)are determined as a key technology to guide roof cutting and pressure relief.
shaped charge blastingcrack extensioncharging parametersroof cutting and pressure reliefnon-pillar mining
NETL
NSTL
万方数据
