Prediction And Prevention Of Rock Burst In Deep And Thick Coal Seam Roadway Of Mengcun Coal Mine

It is of great engineering value to carry out research on prediction and prediction of impact ground pressure in deep and thick coal seam roadway.Based on the engineering background of Mengcun Mine in Binchang Mining Area of Shaanxi Province,this paper analyzes the precursory information and prevention technology of impact ground pressure through theoretical analysis,indoor test and on-site measurement.It mainly does the following work:(1)The main reason of the impact ground pressure in the coal seam roadway of Mengcun Coal Mine is analyzed.It is found that the maximum horizontal principal stress is 1.66-2.10 times of the vertical principal stress during the roadway excavation process,which belongs to the tectonic high stress.The Mengcun coal seam is a deep buried coal seam with an average buried depth of 672m.The ground stress is large and its mechanical properties are quite different from those of the shallow part.The coal seam is an extra-thick coal seam with an average thickness of 19.95m and thin and medium-thick coal seams.Compared with the impact,the ground pressure is more than the release energy,the damage area is large,and the influence range is wide.The coupling between the dynamic load generated in the mining activity and the static load under the original high ground stress is the main factor that causes the impact ground pressure to occur.(2)Through the three-axis static load test of coal rock indoors,it is found that the larger the confining pressure,the more the elastic deformation performance of the internal storage of coal,the more energy is released during the failure;the experimental study on the internal triaxial dynamic and static load of coal rock shows:The lower the frequency under the condition of amplitude and confining pressure in the triaxial dynamic static load combination,the more energy is released when the damage occurs;the amplitude of acoustic emission under the dynamic load shows a phase change characteristic,and its rapid rise phase can be used as Precursor information on the destruction of the coal body,thereby predicting the period of time during which the damage occurred.(3)A hierarchical monitoring and early warning technology is proposed for the impact pressure mechanism of Mengcun mine roadway.The hierarchical monitoring model is adopted,which absorbs the advantages of the comprehensive index method,the microseismic method and the drill cutting method,and forms a“global-region-The characteristics of"local"form the characteristics of“real-time-dynamic-continuous”in time,which provides a reasonable and effective prediction method for the prediction of the impact pressure of Mengcun mine roadway.(4)Based on the concept of"strong unloading strong support,shock absorption and energy absorption",a comprehensive prevention and control scheme combining the composite support system of rock-filled rectangular roadway and large-diameter borehole pressure relief is proposed.The engineering practice shows that the proposed anti-shock The measures are reasonable and effective.