Study On Roof Separation And Support Optimization Of Roadway In Longde Coal Mine

Roof separation is a factor affecting the stability of roadway roof,especially when the roof strata outside the anchorage section are very easy to lead roof to collapse when the strata are separated.Therefore,studying the roadway roof separation value of specific conditions and judging the supporting state of roadway and taking corresponding measures are great significance for the actual production of coal mines.Based on the actual background of Longde coal mine,the law of roof separation in Longde coal mine is studied,and the actual separation value of roof is measured.By comparing,the effect of roof control is determined,and the support is strengthened or the support is optimized.Based on the basic geological conditions of the 201 working face,explore the mechanism of roof separation and different forms of separation.According to the load theory,span conditions and deflection conditions,we have identified the phenomenon of separation between the 3 rock strata of the roof.Through 3DEC software,this paper simulates the influence of six factors such as ground stress,mechanical property of surrounding rock,width of roadway,size of coal pillar,anchoring mode and mining movement on roof separation law.The results show that the roof separation increases with the increase of vertical stress,horizontal stress and roadway width,and decreases with the increase of rock friction angle,cohesion and roof support strength.However,the tensile strength of roof rock has little effect on roof separation.The critical value of roof separation is determined to be 72.8mm by the empirical formula of the general institute of coal science,the method of maximum extension value of anchor bolt and numerical simulation.The measured data found that the total value of 32mm roadway roof separation,only reached the critical value of 44%,the top and bottom separation value is smaller;total close quantity is 182mm,the convergence between the two sidewalls of 149mm,the roadway deformation is smaller;groove bolt stress is the biggest increment 74kN,about 52kN,the 209 auxiliary transport crossheading bolt the force does not exceed 40kN,the increment was 3 kN,the stress of anchor is small.The measured data show that the supporting state of the roadway is good,and it can completely resist the deformation of the surrounding rockIn order to improve the mining rate and save the supporting material,the supporting parameters are optimized.Through theoretical calculation,the width of coal pillar in protective lane should be greater than 12.1m,and the row spacing between bolts is less than 12.8m.The width of optimized coal pillar will change from 20m to 12.5m,and the row spacing between bolts is 1000*1000mm.