Research On Long-hole Pre-splitting Controlling Blast Technology Improveing Gas Extract In Low Permeability Coal Seam

Long-hole pre-splitting controlling blast is a measure that is used to improvepermeability of coal seam and strength gas extraction developed in recent years.Long-hole pre-splitting controlling blast in coal seams is to solve the problem that gasextraction rate of the permeability of coal seam is very low in a new way，Meanwhile，it is very important practical significance to prevent gas outburst and guarantee safetyproduction in coal.This paper mainly is basic on the theory of coal seam gas and long-holepre-splitting controlling blast mechanism，the paper detailed discussed and analysis thecharacteristics of long-hole pre-splitting controlling blast，and that the explosivesexplode and impact process in the coal seams. According to the knowledge fromblasting mechanics, mechanics of elasticity theory，studying technology that is calledlong-hole pre-splitting controlling blasting，and preliminarily determines the blastingparameters. Utilizing RFPA-Flow solid and gas coupling system， established amathematical model of the long-hole pre-splitting controlling blast，and simulate andanalysis with the help of (RFPA2D)numerical simulation software，study coal aroundblasting holes broken and change of stress field、acoustic emission field、elastic filed.And with historical material of Henan coal chemical company’s hemei eight ore，settinga group optimal blasting parameters for its work and test in the field.The study shows that：long-hole pre-splitting controlling blast can reduce terrastress and gas pressure effectively，increase the coal cracks around the boreholes in acertain extent，further extend efficient draining radius，increase the coal permeablecoefficient，and finally raise the coal seam’s gas-extracting quantity and gas-extractingrate. Besides，it reduces me menace of coal-and-gas outburst，further solves the problemof gas concentration and gas outburst on working face in the high gas-outburst coalseam．Therefore，it is a technology with great valuable to popularize.