Research And Application Of Drilling Pressure Relief Layout Parameters In Coal Mine Roadway

Due to the complex geological situation of the mine,and with the increasing of mining depth,the stress concentration of coal and rock around the roadway is increasingly prominent,which is easy to lead to rock burst disaster.Drilling pressure relief technology can effectively reduce the high stress of coal and rock mass near the roadway,and can transfer the peak stress to the deep surrounding rock.In addition,it has the advantages of simple construction technology and low economic cost,and has been widely used in various measures to prevent rock burst.Therefore,It is of great scientific significance and engineering value to study the mechanism of drilling pressure relief and reasonably arrange drilling parameters.At first,this paper adopts the method of theoretical analysis to explore the mechanism of borehole pressure relief,applying borehole in the coal with impact danger,make the coal and rock mass around borehole form a larger area of the break zone and the drilling area interconnected of fractured formation,the formation of a wider range of unloading zone,reduce the transfer and stress of the roadway surrounding rock near the peak,and unloading effect,moreover,According to the theory of elastic-plastic mechanics,the force analysis of a single borehole is carried out,and the range of residual strength zone,plastic softening zone and elastic deformation zone formed successively from inside to outside of the borehole is obtained.Accordingly,the basis for determining the layout parameters of the borehole is given.Secondly,FLAC^3D numerical simulation software was used to establish the test roadway model,and the deformation characteristics and stress distribution law of surrounding rock during roadway excavation were respectively simulated under different mechanical properties of coal seam and buried depth.At the same time,by using numerical simulation method to study the effect of drill hole arrangement parameters on the effect of pressure relief,analysis of the single variable,keeping other parameters constant,observation of roadway and the stress distribution characteristics of coal and rock mass around borehole,it is concluded that when the unloading effect,the optimal drill hole arrangement parameters combination,and proposes the selection of the hole diameter needs to deal with the relationship between the unloading effect and the stability of surrounding rock,The spacing of drilling holes should ensure that each pressure relief area is interconnected,and the depth of drilling holes should reach or exceed the stress concentration area of roadway surrounding rock,and the layout of drilling holes can be reasonably selected according to their respective pressure relief characteristics.Finally,the results of theoretical analysis and numerical simulation in this paper have been effectively verified in the practical engineering application of Zhaolou Coal Mine 7302 working face.The site microseismic monitoring system shows that the borehole pressure relief has achieved the purpose of preventing rock burst,which proves the rationality of the research results.Figure[51]Table[15]Reference[83]...