Study On Prediction Of Danger Of Rock Burst Of Fault Environment In 3306 Working Face Of Yangcheng Coal Mine

Fault structure is the product of relative movement on both sides of rock layer after fracturation,and it is one of the influencing factors of geological structure induceing rock burst.The mining activities in the fault area have broken the original balanced state.A large number of field facts have proved that the rock burst is prone to happen near the fault,and it even can cause the dislocation of the fault itself,which has caused huge disasters to the underground personnel and facilities.The process of rock burst is very complicated,so it is difficult to solve it accurately by mathematical model.However,there is a lot of precursory information before the impact ground pressure occurs,and the most intuitionistic form of these information is all kinds of rock burst monitoring data,especially the monitoring data of continuous time,it is the result of the coaction of coal and rock system under the influence of various factors,and it is also the inevitable result of the inoculation,development and occurrence of rock burst.Therefore,in this dissertation,based on the engineering background of 3306 face in Yangcheng Coal Mine,with the help of numerical simulation software flac and time series analysis Eviews software,the main control factors of pre-mining induced impact ground pressure and the time series of micro-earthquake in mining process were studied.The main conclusions are as follows:(1)According to the precondition of rockburst occurrence and combined with the principle of static and static superposition induced rockburst,it was concluded that static load determines the magnitude of residual energy of impact,and dynamic load mainly plays the role of triggering impact.From the point of view of original stress,the main factors of fault environment induced impulse were studied.(2)Based on the mechanism of rock burst and the relationship between stress and energy and the principle of superposition induced by dynamic and static loading,the index of measuring the magnitude of impact danger was determined:stress gradient and elastic specific energy.(3)By looking for various factors of impact induced by fault environment,the influences of "buried depth","fault type","fault dip angle","fault drop" and "coal seam thickness" on the impact ground pressure were determined.Through the orthogonal numerical test,the main controlling factor of the fault environment was "buried depth".(4)Based on the analysis of the monitoring indexes of two types of microseismic systems,SOS and KJ551,in Yangcheng Coal Mine,the single day maximum energy of microearthquakes was selected as the early warning index for microseismic monitoring in fault environment.(5)Based on the single day maximum energy monitoring data of micro earthquake on 3306 working face,a combination model of regression and time series was established by using Eviews software.That was,dlnnt=0.65d ln zt-0.96d ln nt-1-0.8?t-2(6)From the angle of qualitative(main control factor method)and quantitative(synthetic index method,possibility diagnosis method,etc.)before mining,the impact risk of 3306 face was analyzed,and the model was used to predict the sample extrapolation during the mining process.It turned out that danger warning can be realized.