Study On Breeding And Evolution Law Of High Energy Level Mining Tremor And Disturbance Effect Of Surrounding Rock

In recent years,the depth of coal mining has gradually increased,and some mines in Ordos mining area have entered the stage of deep mining.Under the influence of complex deep mining conditions and geological changes,mine earthquakes are more and more serious and harmful.There is a lack of systematic research on the breeding and evolution mechanism of mine earthquake under the condition of deep well mining and economic and effective treatment measures,which is not conducive to the construction and development of modern mine with high yield and high efficiency.Therefore,this paper takes 2215 working face of Yingpanhao Coal mine as the research background,analyzes the breeding and evolution law of mine earthquake and its influencing factors under the condition of deep well and thick bedrock,reveals the focal process of mine earthquake under different influencing factors,explores the disturbance effect of mine vibration load on roadway surrounding rock and puts forward the corresponding load reduction and shock absorption prevention scheme.Based on the determination of key strata,the development height of the "three zones" of overlying rock,the spatial distribution characteristics of microearthquakes under overlying rock activities,and the spatio-temporal evolution of microearthquakes,it is concluded that the roof periodic compression during the mining of 2215 working face is the main incentive for the occurrence of large energy mining tremors,and the basic roof periodic compression only provides a basic environment for stress concentration.The occurrence of large energy mining tremor events is also controlled by other important factors such as lateral abutment pressure in goaf,fault and connecting roadway.The load source and inducing factors of mine tremor are determined,which provides a theoretical basis for subsequent research.The moment tensor inversion method is used to carry out a quantitative analysis of the source waveform,study the source mechanism and the response law of mechanical parameters,further analyze the fracture characteristics of the source in the frequent mining tremor areas such as fault,tunnel connection,advance abutment pressure peak,and reveal the mining earthquake leading fracture mechanism and evolution process under the occurrence characteristics of the coal seam,and further confirm the above conclusions from the microscopic level.It provides the basis for the prevention and control measures of different types of mining tremors in the later coal mine.Based on UDEC discrete element numerical analysis software,the instability process of roadway under the action of tremor load disturbance is simulated,and the damage and failure characteristics of roadway surrounding rock under different conditions are analyzed.Through changing dynamic load strength,it is concluded that the larger the dynamic load strength is,the larger the disturbance range and damage degree of roadway will be.When the dynamic load strength is 25 MPa,the dynamic characteristics of roadway are obvious.Prone to impact damage;According to the analysis of changing dynamic load horizon,the closer the dynamic load horizon is to the roadway,the less weak rock strata will pass through,the smaller the energy dissipation will be,and the greater the impact of dynamic load on roadway damage.At the same time,changing the weakening coefficient of the hard roof verifies the feasibility of reducing the disturbance of the roadway caused by dynamic load.Based on the theoretical analysis and statistical data results,according to the tremor load source and inducing factors of 2215 working face mine,the targeted seismic load reduction and shock absorption prevention and control measures of high energy mine are formulated according to the zoning classification,forming the "top-coal-bottom" zoning classification comprehensive load reduction and shock absorption prevention and control system.At the same time,based on the microseismic data of 2215 working face and the statistical analysis results of footage,combined with the existing supporting capability of the working face,the prevention plan of mining tremor area is formulated.Through the engineering effect test,it is confirmed that the high energy mining tremor prevention scheme is feasible.It provides the research foundation for the early warning and prevention of high energy mining tremor or rock burst disaster,and further improves the early warning level and coping ability of mine strong earthquake.This thesis has 68 figures,15 tables and 94 references in this thesis.