Mechanism And Control Of Rockburst Induced By Mutual Feedback Of Static Load And Coupling Of Dynamic Load Under Mutual Disturbance Of Mining And Excavation Conditions

Rock burst is one of the typical coal and rock dynamic disasters.The mutual disturbance of mining leads to the superposition of dynamic and static stress fields in different working faces and induces the disturbance type rock burst,which seriously affects the safety of production.In this thesis,field investigation,theoretical analysis,mechanical test,similitarity simulation,numerical simulation and engineering practice are used to study the coupling mechanism of mutual disturbance of mining and mining.The characteristics of rock burst induced by mutual disturbance of mining and excavation are investigated and analyzed,and the whole classification is made.The disturbance impact has the typical characteristics of being significantly affected by mining,the excavation roadway is more susceptible to stress disturbance of the mining face,the impact strength of the mining face is higher than that of the excavation roadway,and the dynamic damage is obvious.According to the disturbance object,position relation,disturbance direction and combination type,the research objects are divided.Among them,the disturbance degree of dynamic and static stress between the facing stope face is the strongest,which is easy to induce shock.The mutual feeding process of mining stress field and the coupling mechanism of complex dynamic load were revealed.With the approach of relative distance,the different stages of mutual feeding between mining and excavation face under static load are divided.The influences of raw rock stress,stress concentration coefficient,roadway height,coal strength and other factors on the degree of mutual feed disturbance are discussed.Under the given conditions,the range of static load disturbance of mining face facing opposite direction,mining face facing opposite direction and driving face facing opposite direction is 60 m,30m and 5m respectively.In terms of reducing dynamic load disturbance caused by composite mine seismic,the relative safe distance of working face should not be less than 500 m.The anisotropic stress at the interface of deep surrounding rock and anchorage structure is positively correlated with PPV and proportional to frequency.It is determined that the roof of roadway and the oblique direction of 45° should be strengthened under the action of composite dynamic load.There are three kinds of co-phase superposition,reverse superposition and opposite superposition in the co-phase superposition process,among which the dynamic load increment corresponding to the co-phase superposition is the highest,which is easy to induce the impact.The induced impact effect of coal mass under stress disturbance load is revealed.The higher the quasi-static load rate and stress level,the amplitude and frequency of cyclic load,the transient load increment and stress level,the weaker the resistance to disturbed load,the faster the energy accumulation and release,and the more severe the dynamic failure.Before the disturbance load,the elastic strain energy is mainly stored.During the disturbance stage,the elastic energy is rapidly released into the macroscopic expansion of coal mass and the kinetic energy and heat energy of particle ejection.Three kinds of impulse inducing effects of disturbance loads,namely "high static load dominant type","mine seismic fatigue dynamic load dominant type" and "instantaneous impact dynamic load dominant type",are summarized.The evolution characteristics and progressive damage mechanism of the mutual disturbance of mining and excavation are revealed.In the process of quasi-static mining,the disturbance near the excavation face causes the static load to rise gradually,and the upper strata does not break,which does not reach the impact starting condition.With the increase of external dynamic load intensity,the dynamic response of surrounding rock becomes more severe,so the critical impulse induced energy of mining face and excavation face is obtained.The evolution of mining stress,the law of energy accumulation and release,and the dynamic load response characteristics of surrounding rock in the process of face mining are studied.It is concluded that the disturbance type impacts of "high static load + high dynamic load" and "high static load + low dynamic load" are formed at different stages in the process of mutual disturbance of mining and mining.The impact mechanism model is established,the dynamic and static load source is determined,and the criterion of the impact induced by the mutual disturbance of mining and excavation is put forward.A technical system of pre-mining assessment and separate source load reduction,shock absorption and shock prevention for mining and mining mutual disturbance induced working face is proposed.A separate source warning method based on the coupling principle of "stressvibration-energy" is proposed,and a targeted control scheme is given.The research results were carried out in the engineering practice,which effectively reduced the impact risk and achieved good social and economic effects.The dissertation contains 156 figures,13 tables,and 180 references.