Research on Coal Pillar Width and Support in the Roadway Along Goaf Section of Inclined Coal Seam Semi Coal Rock
In view of the problem of instability and large deformation of the surrounding rock caused by the unreasonable width of section coal pillars during the stoping process of the inclined coal seam semi coal rock roadway along goaf in Changxing Coal Mine,taking the 1163 working face as the research object,a coal pillar model of the inclined coal seam semi coal rock roadway along goaf is established based on the limit equilibrium theory.A numerical calculation formula for the reasonable width of the coal pillar is proposed,combined with engineering geology and on-site construction conditions,the reasonable reserved width of the coal pillar is determined to be 4.89-5.24 m;by numerical simulation of the failure characteristics of roadways under the condition of coal pillars with different widths,it is determined that the width of the coal pillar in the section is 5 m.Combined with the asymmetric failure characteristics of semi coal rock roadways,a joint con-trol scheme of"filling behind U-shaped shed wall+asymmetric through layer grouting anchor cable"is proposed;The on-site industrial test results show that after leaving and setting up coal pillars with a width of 5 m and adopting the joint control scheme,the bearing capacity of the surrounding rock can be effectively utilized,and the deformation amount of the roadway surrounding rock can be significantly reduced,meeting the requirements of safe and efficient production in the working face.