Research On The Energy Attenuation Law Of Mine Outburst Shock Wave Buffered By Elastic Devic

The proportion of coal and gas outburst accidents in coal mine accidents is increasing year by year,and the accident casualties are relatively serious.Especially,the huge energy of outburst shock wave is easy to cause serious damage to underground workers and ventilation facilities.Therefore,based on the research on the existing roadway obstacles to weaken the impact energy and prevent the accidental release of energy,this paper designs an elastic device installed on the two walls of mine roadway to accelerate the attenuation of mine outburst shock wave energy,and artificially accelerates the attenuation of mine outburst shock wave energy to the safety level.The numerical simulation software Fluent was used to study the attenuation law of the outburst shock wave energy under three effective section changes（unchanged,enlarged and reduced）,three outburst pressures（0.6 MPa,0.8MPa and 1.0 MPa）and two elastic device models.The structural model of the elastic device required to accelerate the attenuation of the outburst shock wave energy to the safe level is determined.The main research results are as follows:（1）The propagation attenuation law of the outburst shock wave and the action principle of the elastic device are analyzed,and the physical geometry model and the energy propagation system model of the outburst shock wave under the buffer of the elastic device are established.The results show that the energy attenuation of shock wave can be accelerated by artificially adding an elastic device in the roadway,and sufficient space behind the area where the elastic device is arranged can avoid the harm caused by the local pressure surge caused by the excitation effect of obstacles.When the effective section of the elastic device decreases in turn,A₀₁<A₀₂<A₀₃<A₀₄,and the area change rate A_0i/A keeps increasing,the attenuation speed of the energy of the protruding shock wave will become larger and larger,and the final energy attenuation effect is the best.（2）Through the numerical simulation of elastic devices with different effective section changes,it is concluded that the change of effective section will affect the attenuation degree of shock wave energy.When the effective section changes,the pressure at each measuring point decreases the fastest,and the attenuation degree of the outburst shock wave energy is also the largest.Elastic devices with different effective section changes can accelerate the energy attenuation of shock wave.The more elastic devices are set,the less energy of shock wave will be transmitted to the end of roadway at the same time.（3）The numerical simulation study by changing the outburst pressure shows that the change of the outburst pressure has a certain influence on the effective section of the elastic device when the effective section of the elastic device remains unchanged and becomes larger in turn.The pressure at each measuring point increases with the increase of the outburst pressure in the same trend,but the effect on the effective section of the elastic device becomes smaller in turn.This indicates that when the effective net fault area of shock wave propagation increases intermittently,the effect of accelerating shock wave energy attenuation is very stable and will not fluctuate greatly with the increase of outburst pressure.（4）Through the numerical simulation study by changing the elastic device model,it is concluded that the second model has a better effect on accelerating the energy attenuation of the outburst shock wave than the first model.Especially,when the effective section changes,the pressure drop is smoother and there is no pressure surge phenomenon.Even when the outburst pressure is 1.0 MPa,the energy of the shock wave can be reduced to the safety level and human body can be prevented from being damaged.It shows that when the total effective section of the same elastic device is basically unchanged,it can be divided into more independent and evenly distributed parts,or fill more gaps in the middle of the roadway,which can enhance the weakening ability of the elastic device to the outburst shock wave energy and accelerate its attenuation.