Study On Combined Antireflection Technique Of Hydraulic Punching And Blasting Antireflection In Gaocheng Coal Mine

Aiming at the problems of poor permeability of coal seam,soft coal quality and difficult gas extraction in Gaocheng Coal Mine,this paper adopts the research method of combining theoretical analysis,similar simulation test and field industrialization test,with the help of dynamic strain meter.In this paper,the mechanism of coal seam enhancement combined by hydraulic punching and blasting is studied in the system,and the technical parameters are optimized.The specific contents of the study are as follows:Firstly,the mechanism of anti-explosion combined with regional pressure-relief antireflection is analyzed.The effects of blasting energy,stress wave,explosion gas and control hole on the crack propagation are analyzed.It is found that the explosion energy is released outward by the stress wave and the explosion gas at high temperature and high pressure,and when the stress wave propagates to the surface of the control hole,The fracture area is further developed by reverse tension,and the crack is expanded by the wedge of explosion gas into the crack produced by stress wave.Secondly,the simulation experiment of flushing and blasting combined with regional pressure relief and antireflection similarity was carried out,and the propagation law of stress wave and the damage characteristics of regional coal seam were obtained.According to similarity theory and similarity criterion,coal and rock mass simulation materials and their proportions are determined,and similar simulation test schemes are designed according to similarity theory,fracture mechanics and geological data of Goucheng coal mine.The experimental results show that the control hole has an obvious guiding effect on the fracture development,and the existence of the control hole provides the space needed by the coal blasting to produce crushing and fracture areas,and at the same time it can eliminate the stress concentration,and the data collected by the dynamic strain meter show that,The stress wave produces obvious repeated stretching action in the coal body.The more close to the blasting hole,the more obvious this action is,and the data can be obtained by means of electric instrument,which is a new method which can observe coal seam cracks directly and clearly,and has practical application value.Finally,the field industrialization test of the combined regional antireflection test was carried out.The measured data show that the influence radius of the combination of flushing and blasting combined with regional antireflection can reach 15m,the concentration of gas extraction and the pure flow rate of the drainage hole are kept at a high level within 48 hours,and the blasting hole is connected to the drainage pipeline for gas extraction.The results show that the blasting hole has a higher concentration of gas extraction than the drainage hole,and the extraction effect is better than that of the drainage hole.The combination of flushing and blasting combined with regional pressure relief and antireflection technology can play a better antireflection effect in soft coal seams with low permeability and greatly improve the efficiency of gas drainage.The results of the study are of great value to the similar coal seams in China,especially the soft coal seams with high gas and low permeability.