Reasonable Setting and Safety Evaluation of Protective Coal Pillar Under Bridges and Tunnels of Railway

Based on the transporter line from Tarangaole Coal Mine to Hanjia Village of Shenhua Group Baoshen Railway, the protective coal pillars under bridges and tunnels were preserved, and the coordinated protecting technical measures of underground and surface combined mining for the railway were proposed. The quantity of protective coal pillars was estimated, and the safety was evaluated. The results showed that 32.580 4 million tons of coal would be more exploited, and the resource recovery rate was increased by 51.5%, the maximum subsidence was 2.341 mm, the maximum inclination was 8.3 mm/m, and the maximum horizontal deformation was 2.5 mm/m caused by mining of every coal seam, which could be adjusted with maintaining technical measures. Therefore, mining under railways in this area is safety.