Disturbance law of mining speed of steeply inclined coal seam to coal and rock mass
Because of the complex occurrence environment of steeply inclined coal seam,the disturbance effect of coal and rock mass by advancing speed is obvious,so a numerical model of steeply inclined coal seam mining is constructed to obtain the evolution law of stress and energy of coal and rock mass under different advancing speeds.We statistically analyze the characteristics of microseismic energy-frequency,output and recovery rate under different advancing speeds,and determine the reasonable advancing speed based on the coupling relationship between advancing speed and pressure relief.The numer-ical simulation results show that after coal mining,the rock pillar is bent and pried,and a region of high stress concentration and high energy accumulation is formed near the roof of B1+2 coal seam.With the increase of advancing speed,the degree of high stress concentration and high energy accumulation in the rock pillar is increased,and the bending and pried effect of the rock pillar is more obvious.The results of microseismic monitoring show that with the increase of advancing speed,the frequency and energy of microseismic events increase,the disturbance degree of coal and rock increases,the output increases but the recovery rate decreases,and the coal loss increases.Based on the coupling analysis of advancing speed and pressure relief,the K value of single-day output/single-day explosive consumption is put forward,and it is concluded that when the advancing degree is 3.2 m/d,the K value is the largest,and the K value decreases when the advan-cing degree is reduced and increased,so the advancing speed can be appropriately increased under the conditions of ensu-ring the safety of pressure relief.The study provides some reference for determining the advancing speed of steeply inclined seam.
steeply inclined coal seamadvancing speedcoal and rock massmining disturbancepressure relief regulation
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