Research On Cumulative Blasting Technology For Improving Coal Seam Permeability And Roof Weaking

Based on cumulative effect of cumulative charge, coal and rock splitting mechanism was studied. The cumulative blasting process, fracture initiation and extension condition and fracture partition characteristics were analyzed. At the same time, the safety of cumulative explosives and hidden danger of blasting circumstances were analyzed. Divide the cumulative explosion process into five steps including locating, drilling, loading, sealing and detonation. Aiming at the possible accident in the process, the corresponding safety technical measures were adopted to ensure the field test smoothly. Using Songshu Coal Mine of Tonghua Mining(Group) CO., Ltd as a test field, mine gas geology law including geological structure, coal seam existence, gas drainage and coal and gas outburst characteristics and its geological reasons were studied. On this basis, deep-hole cumulative blasting was applied to improve permeability in the low gas permeability coal seam and roof weakening in hard and stable roof, and test plan was designed as well as implemented. The result shows that cumulative blasting works well to improve coal seam permeability and provides technology and method to solve large area hanging roof, which ensures the safe production of working face.