Numerical simulation and influence analysis of coal seam outburst risk with different coefficient of variation
To reveal the influence of coal seam thickness variation on the outburst danger of coal seam,a coupled model of coal seam deformation field and gas field was established,and coal seam models with different coal seam variation coefficients were established based on Gaussian distribution.The dis-tribution laws of stress field and gas field under different variation coefficients were studied.The main research conclusions are as follows:there is a significant difference in stress field between stable coal seams and unstable coal seams.The unstable coal seams form stress concentration phenomenon at thin coal seams,which decrease linearly when excavating towards thick coal seam areas.The stress of stable coal seams is greater than that of unstable coal seams at the thick coal seam,and the stress decreases further with the increase of coal seam variation coefficient.The stress of coal seams with different varia-tion coefficients gradually increases with the increase of variation coefficient,and the growth rate of the principal stress increases with the decrease of advancing distance.The thickness variation of coal seam leads to the lateral force of the roof acting on the coal seam.For the thin coal seam,the lateral force of the roof is directed towards the coal seam,which leads to stress concentration at the thin coal seam.For the thick coal seam,the lateral force of the roof deviates from the coal seam,resulting in smaller stress than that of the thin coal seam.In addition,with high gas concentration,low permeability,and more de-veloped structural coal,it is prone to outburst under disturbance.
coal and gas outburstcoal seam thicknesscoefficient of coal seam variationmultiphysical fieldgas pressure
万方数据
维普
