Research on the breaking mechanism of bolts and cables in the gateway driven along a small coal pillar in the Datong mining area and the corresponding control technology

The gateway of the thick coal seam working face in Datong mining area was excavated along a small pillar, resulting serious bolt (cable) breaking failure, strong surrounding rock deformation, ground pressure appearance, and difficulties control. So, characteristics corresponding causes 5106 return air with pillar Dongzhouyao mine (a area) were analyzed through an on-site investigation, geotechnical parameters test, theoretical analysis, laboratory experiment, engineering other research means. study carried out testing analysis on stress distribution laws bolts, put forward mechanism prevention countermeasures, completed field industrial test relief support joint control technology gateway. tracking data showed that conditions bolts (cables) significantly reduced by improving initial force (cables), optimizing supporting materials components, canceling ring, implementing hydraulic fracturing top cutting + high prestressed full cable technology. displacement bottom plates 51%, two sides 46%, influence distance advance from 85 m to 30 m. successful implementation results provided reference for promotion application similar area.