Experiment study on deep hole pre-splitting blasting technology in low permeability outburst working face

In order to solve the problems of gas drainage difficulties and long construction period in ow permeability outburst working face of mining process,it was proposed to adopt deep hole pre-splitting blasting technology to increase the coal seam fracture and seam permeability.The mechanism of deep hole pre-splitting blasting technology was studies,the process of deep hole pre-splitting blasting technology was described,and the effect of permeability increasing was tested in site.The results showed that: for the deep hole pre-splitting,blasting compared with before blasting,the average gas extraction volume increased by 2.32 times and the average seam permeability coefficient increased by 5.6 times,maximum 11.5 times,and it improved the gas pumping rate effectively.The stope cycle of working face shortened considerably,and it provides a guarantee for the safe and fast recovery.