Research On High Gas Coal Seam Long Hole Blasting Pre-split And Antireflective Technology

In recent years, China’s coal mine gas accidents occur frequently, causing huge loss ofpersonnel and property, face our country to control gas and coal-bed methane mining technicaldifficulties, especially for low permeability coal seam, coal body technology research hasbecome a urgent task.In order to improve coal presplit blasting effect and improve gas extraction rate andshorten the purpose of gas drainage time, based on previous research achievements, and on thebasis of rock mechanics, mechanics by blasting and fracture mechanics theory, this paperanalyzes the physical and mechanical properties of coal blasting effect and the influence of thepresplit blasting long the mechanism; Using ls-dyna software to simulate the group leader holepre-split blasting process of initiating direction, have without controlled hole hole blastingholes, control and the different distance and hole spacing rupture range of factors and theinfluence of the presplit blasting long technical advantages and disadvantages are analyzed.The simulation results show that, long hole pre splitting blasting, reverse priming thanpositive initiation has better blasting and presplit effect. Presence control hole blasting is betterthan no control hole blasting. Control hole, can control the stress wave propagation direction,improve the blasting effect, increase the crack production and control, hole played a role ofcompensation compensation space, the broken zone and loose zone space required, so that afterthe bursting of the coal body relatively even without being compacted. Conducive to thecontrol hole near the main crack and secondary crack propagation. Improving the effectiveutilization rate of the explosive, can enlarge the rupture of coal range. Control hole and the holeblasting of different distance simulation, shows that the long hole blasting of effective radius is3-3.5m, therefore can be calculated, the optimal blasting hole spacing should be6-7m. Longhole blasting in favor of coal fissure, improve the permeability of the coal seam, but in theprocess of blasting, gas pressure on blasting effect and how to develop the gas outburstdangerous coal seam this technique does not induce gas outburst measures and eliminate othersafety aspects, need further research.It is of realistic significance to reserch pre-splitting blast technology in coal seam. Studyresults in this paper will provide theory basis for blasting parameters optimization and inspirefurther study ideas of pre-split blasting near the blasthole.