Experimental Study On Dynamic Response And Rockbusrt Characteristics Of Roadway With Combined Support Of Anti-burst Shell And Energy Absorber

Coal mine rock burst seriously affects the safety production of coal mine and causes the instability and failure of roadway because of its complexity,sudden occurrence and severe damage.Protecting the safety of personnel in roadway is one of the most important tasks in mining production.How to improve the impact resistance of roadway more effectively has become an urgent problem to be solved in coal mines.The energy-absorbing body support such as adding energy storage structure and anti-scour support in roadway has been proved to be effective through field practice,but the combined mechanism of bolt and energy-absorbing body is not clear.This thesis focuses on the key problem of ’ dynamic response and impact characteristics of surrounding rock of roadway with combined support of anti-impact shell and energy absorber ’.Firstly,based on the theory of rock burst induced by dynamic and static load superposition,the whole process of instability and failure of roadway under dynamic and static load combination is simulated,and the dynamic response characteristics of anchorage roadway and the mechanism of anti-impact shell structure are studied.Subsequently,the similar simulation test of dynamic and static load superposition of ’anti-impact shell-energy absorber ’ combined support roadway was carried out,and the dynamic response and impact failure characteristics of bare roadway,anchoring roadway and anchoring-energy absorber combined support roadway were compared and analyzed.Then,the influence of different energy absorption support parameters on the dynamic response and impact characteristics of the roadway is systematically analyzed.Finally,based on the theory of dynamic and static load superposition and surrounding rock cracking and buckling,the transient trigger-chain failure impact model of surrounding rock is established,and the anti-scour mechanism of anti-scour shell-energy absorber combined support is studied.Research shows that :(1)When the dynamic load strength is small,the surrounding rock of the roadway remains stable without obvious displacement.With the increase of dynamic load strength,the stress concentration in the surrounding rock of anchorage roadway is obviously enhanced,and the particle vibration velocity of surrounding rock also increases.When the dynamic load reaches a certain strength,the roadway is instantaneously damaged,the vibration velocity and displacement of the surrounding rock are abruptly changed,and the impact damage intensity of the roadway increases with the increase of the dynamic load strength.(2)In the dynamic and static load test of the model,when the dynamic load energy is 196.0 J,the bare roadway is destroyed,when the dynamic load energy is 431.2 J,the anchoring roadway is destroyed,and the anchoring-energy absorber combined supporting roadway is only slightly deformed.At the same time,when the dynamic load energy increases by 39.2 J,the vibration acceleration of the bare roadway increases by approximately 1.0 times,and the vibration acceleration of the anchoring roadway increases by approximately 0.5 times.The vibration acceleration growth rate of the anchoring-energy absorption combined support roadway is similar to that of the anchoring roadway,but the vibration acceleration value is significantly lower.Therefore,the combined support of anti-scour shell and energy absorber can further improve the impact resistance of roadway.(3)The research on the influence of energy absorption support on the dynamic response and impact characteristics of the roadway shows that after the energy absorption support is added to the roadway,under the same dynamic load,the deformation of the roadway floor is reduced from 0.95 m to 0.05 m,and the deformation of the right side is reduced from 0.4 m to 0.1 m.With the increase of damping force and number of energy absorbers,the peak vibration acceleration of floor can be effectively reduced,the attenuation of vibration velocity can be accelerated,and the risk of roadway impact can be reduced.(4)The transient triggering-interlock failure impact model of surrounding rock shows that the impact load generated by the first fracture of coal body caused by the superposition of dynamic and static loads is transmitted from the inside of surrounding rock to the outside.When the surface rock mass of the roadway is destabilized and broken,the surrounding rock of the roadway is continuously destabilized from the outside to the inside in an instant,which better expounds the continuous release process of the accumulated energy of the surrounding rock.The combination of bolt and energy absorption support is conducive to controlling the fracture instability of the surface rock mass of the roadway,forming an effective supporting effect on the internal rock mass,and inhibiting the continuous failure and instability of the internal rock mass.