Blasting parameter study of deep-hole cumulative blasting to improve coal seam permeability

In view of the technical parameters of cumulative blasting to improve the permeability of coal seams with low permeability, under the condition of constant charge diameter, blast holes were designed with different charge coefficients and blast spacings, and then field test was carried out. The variation of gas drainage pure quantity before and after blasting was comparatively analyzed in blasting influence area, and the influence of blasting parameters on the permeability-increasing effect of coal seams was investigated on the basis of experimental data. It is shown that the permeability-increasing effect of coal seams can be improved by controlling blast-hole radial charge decoupling coefficient, axial charge length, sealing reliability, and blasting times.