Narrow coal pillar width optimization and surrounding rock control for 3200 working face of Nanguan Coal Industry

Taking the background of Nanguan Coal Industry 3200 working face’s initial retaining narrow coal pillars for excavating roadway along goaf，the reasonable width of retaining coal pillars and the control technology of surrounding rock stability were researched.By theoretical analysis and calculation，the distance between the fracture position of key rock block B in the 3200 working face and the coal wall in the goaf is obtained.By taking into account the anchor rods and safety margins，a reasonable width range for the coal pillar is determined.Based on the numerical simulation results，when the width of the coal pillar reaches 8 meters，the maximum vertical stress within the coal pillar wall surpasses that of a physical coal pillar wall，which confirms the advantage of 8 meter coal pillar in optimizing stress distribution and controlling the deformation of surrounding rock.By analyzing the range of advanced disturbance and combining the initial pressure step distance，it is determined that the advanced support distance should be kept at more than 40 m.A combined support approach consisting of “anchor rods，steel mesh，Wsteel strips，and anchor cables” is proposed for the 3200 material roadway，thus effectively controlling the deformation of the surrounding rock in the roadway，and ensuring the safe and efficient mining of the working face.