Study on protection and support technology of small coal pillar in thick coal seam

In order to solve the problem that the coal pillar of thick coal seam in Changping Coal Mine was large and the deformation of the roadway was serious, t he feasibility and the surrounding rock control scheme of the small coal pillar roadway in Changping Coal Mine were studied by theoretical analysis, numerical simulatio n and engineering analogy. The concept of supporting the 6 m wide coal pillar and the' 'closedcontrol of the whole surrounding rock" was put forward, and the field test wa s carried out in No.4309 mining face of Changping Coal Mine. The results showed that the whole supporting scheme of shallow excavation, timely bolting and cable sup port, floor anchorage pouring strengthening, secondary and timely spraying and anchor ( cable) .The overall structure of the 6 m wide coal pillar on both sides of the roa d to help anchor reinforcement, ahead of the working face 20 ~ 40 m and lagging face 50 ~ 100 m pillar grouting could effectively strengthen the small coal pillar to impr ove its bearing capacity, the use of a beam and three pillars of the roadway and retaining the road ahead of 40 m shed support, 100 ~ 150 m after the face of the roadw ay stay support could further reduce the dynamic pressure under the roadway deformation.